[cctalk] Re: LCM STL Files for 3D Printing of DEC PSU Chassis

[Anders Nelson via cctalk]

Great fix!

I'd like to suggest that anyone distributing 3D models for 3D printing,
please include a STEP file. STLs are mesh based (at least that's how they
load into Fusion 360) and by default you can't align objects to them or
perform other standard operations. I include STEP, STL and F3D (Fusion
source) file formats in all my posts on Thingiverse, Printables, etc.
because my goal is to let people modify them as they need.

=]
--
Anders Nelson
www.andersknelson.com


On Tue, Oct 15, 2024 at 9:20 AM hupfadekroua via cctalk <
cctalk@classiccmp.org> wrote:

> Next try …
>
> https://flic.kr/s/aHBqjBMV48
>
>
> A.
>
> > Am 15.10.2024 um 15:28 schrieb Milo Velimirović <
> milovelimiro...@gmail.com>:
> >
> > The photos didn’t make it through. I’ve got a pdp11/05 that I’d like to
> restore and new PSUs make total sense to me. Please send photos directly.
> >
> > Thanks!
> > —Milo
> >
> >> On Oct 12, 2024, at 6:35 AM, hupfadekroua via cctalk <
> cctalk@classiccmp.org> wrote:
> >>
> >> Hi all,
> >>
> >> Once I visited LCM some years ago I was allowed to visit their repair
> laboratory.
> >>
> >> I was introduced to an approach  to substitute DEC BA11 PSU modules by
> modern DC-DC converter modules.
> >>
> >> They used a 3D printed plastic chassis to mount the converter,
> electrolytic as well as the connectors to be fitted into the psu chassis of
> a BA11 enclosure, quite nice.
> >>
> >> See photo attached …
> >>
> >> Does someone knows if this stl or design has been saved while or after
> LCMs closure?
> >>
> >> Best
> >>
> >> Andreas
> >
>

[cctalk] Re: Microsoft & Apple

[Anders Nelson via cctalk]

Sure seems like Apple recovered, as I type on my Macbook M3 Max! Investing
in developing their Unix-like OS and buying that silicon company were some
of the greatest business decisions I've witnessed.

--
Anders Nelson
www.andersknelson.com


On Thu, Sep 5, 2024 at 12:44 AM Murray McCullough via cctalk <
cctalk@classiccmp.org> wrote:

> I had not realized it was 27 yrs. ago that Microsoft ‘gave’ Apple $150-$200
> million. It was done to keep Microsoft safe from regulators - for its
> monopoly practices. Later did the lawsuits end between Apple and Microsoft.
> Did this save Apple? Haven’t researched this enough to deduce a learned
> response!
>
> Happy computing,
>
> Murray 🙂
>

[cctalk] Re: New VCF Video bumper

[Anders Nelson via cctalk]

Personally I like Brad's idea of a machine sound versus an intro tune. And
if we can reduce background noise (e.g. putting the machine in an anechoic
chamber or surrounding it with acoustic panels) when capturing that sound
it would feel really professional. Might be easier said than done
considering the size of some of these machines, haha.

Acoustic foam: https://a.co/d/7cp3H6g

=]
--
Anders Nelson
www.andersknelson.com


On Mon, May 6, 2024 at 2:26 AM Steve Lewis via cctalk 
wrote:

> I picked the regular Daisy Bell one (except there is a little blip/bump at
> the 2-second mark that is a little jarring).   It's a homage to what the
> IBM 7094 did back in 1961 (while that one did have vocals, it is a bit
> eerie, and so just an audio track like a PDP-1 might play it is good).
>
>
> On Sat, May 4, 2024 at 12:03 AM Jeffrey Brace via cctalk <
> cctalk@classiccmp.org> wrote:
>
> > The Vintage Computer Federation is looking for a new bumper to add to the
> > front and back of all their new videos.
> > There are 7 different versions. Vote on the one that you like best!
> >
> > https://forms.gle/Y9Qrj26xokeFXjub6
> >
>

[cctalk] Re: Double Density 3.5" Floppy Disks

[Anders Nelson via cctalk]

Ha! You mean using the transformer's magnetic field to bamboozle the media?

--
Anders Nelson
www.andersknelson.com


On Tue, Apr 30, 2024 at 1:48 PM John Robertson via cctalk <
cctalk@classiccmp.org> wrote:

> On 2024/04/30 10:08 a.m., Anders Nelson via cctalk wrote:
> > Having grown up with 1.44MB 3.5" floppies, I have a question: is it
> > possible to use a 1.44MB disk and just format it as a 720K disk?
> >
> > =]
> > --
> > Anders Nelson
> > www.andersknelson.com
>
> As I recall you had to bulk erase the old diskette and then you could
> format it as 720 - covering the 1.44 hole of course.
>
> Not bulk erasing (the side of a Weller soldering gun works just fine)
> led to erratic results. We all have Weller guns for fixing computers, eh?
>
> John :-#)#
>
> >
> >
> > On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk <
> cctalk@classiccmp.org>
> > wrote:
> >
> >> Does anybody have any extra 720K (double sided, double density) 3.5"
> >> Floppy Disks that could use a good home?
> >>
> >> If so, please email me directly at bit...@12bitsbest.com.
> >>
> >> Thank you,
> >>
> >>Mike
> >>
>
> --
>   John's Jukes Ltd.
> 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
> Call (604)872-5757 (Pinballs, Jukes, Video Games)
>   flippers.com
>   "Old pinballers never die, they just flip out"
>
>

[cctalk] Re: Double Density 3.5" Floppy Disks

[Anders Nelson via cctalk]

Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?

=]
--
Anders Nelson
www.andersknelson.com


On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk 
wrote:

> Does anybody have any extra 720K (double sided, double density) 3.5"
> Floppy Disks that could use a good home?
>
> If so, please email me directly at bit...@12bitsbest.com.
>
> Thank you,
>
>   Mike
>

[cctalk] Re: SMD/ESDI emulator progress report

[Anders Nelson via cctalk]

Hey Guy,

This sounds like a very cool project. FWIW I commissioned RTL work in
Verilog using Upwork, with very good results. I'm an embedded C and C++ man
myself and can (mostly) read Verilog but couldn't have delivered that code
in a reasonable timeframe. Here's the husband and wife RTL team I worked
with: https://www.upwork.com/freelancers/~01453f295752b85d81. I hope
they're still around, haha.

I also found the Wavedrom tool super useful in creating timing diagrams:
https://wavedrom.com/

Good luck with your emulator!
--
Anders Nelson
www.andersknelson.com


On Thu, Mar 14, 2024 at 3:55 AM Guy Sotomayor via cctalk <
cctalk@classiccmp.org> wrote:

> Hi,
>
> I just wanted to provide a bit of a progress report on the SMD/ESDI
> emulator project.
>
> Now that I'm retired I have a bit more time to actually work on it.
> Previously I was just doing a bunch of research and writing notes on the
> design.  I now have a solid design and I'm starting with the
> implementation.
>
> I'm going to list some of the design goals and then sketch out a few of
> the major issues and how they're being addressed.
>
> Goals:
>
>   * Emulate any drive geometry
>   * Emulate a drive's performance characteristics
>   * Work across different interface types
>   * Fully built emulator cost below $500
>
> Major Issues:
>
>   * SMD/ESDI have head switch times < 10 microseconds (basically the
> time it takes for the read amplifiers to settle on a "real" drive).
> Solving this issue drives the majority of the design
>   * Address marks on a "real" drive are implemented by writing a DC
> signal on the track and the read circuitry detects that and
> generates the address mark signal
>
> When looking at the specifications for SMD and ESDI disks there aren't
> really a lot of difference in how the drive behaves.  The interfaces
> differ in detail but in reality the differences are pretty minor.  So
> the current design should allow for 95+% code sharing between SMD and
> ESDI emulators.
>
> To solve the head switch performance, it is necessary to have an entire
> cylinder in some sort of RAM.  This allows for very fast head switch
> times (e.g. the selected head just addresses a particular portion of the
> RAM).  However, this means that loading a cylinder (which in some cases
> could be as much as 1MB) could take considerable time.  It will take
> even longer if some of the tracks in the cylinder are "dirty" due to
> them having being written to prior to the seek.
>
> Since I want the emulator to be able to faithfully emulate drives in all
> respects, the limiting factor is the cylinder-to-cylinder seek time
> (e.g. moving from one cylinder to another cylinder that is adjacent).
> This is typically in the 4-8ms range.  So doing the math, one must move
> 1MB in 4ms (that turns out to be ~250MB/sec of bandwidth...using 32-bit
> transfers, this means over 60M transfers/sec).
>
> The above implies that the cylinder RAM and where the storage holding
> the cylinders of the image must be capable of at least 60M transfers/sec
> between them.  This is going to involve a complex FPGA that is able to
> have large internal RAMs and a direct connection to some sort of DRAM to
> hold the full image.  I've chosen to use a SOM (System-On-Module)
> version of the Xilinx Zynq 7020.  This has dual 32-bit ARM cores (plus a
> whole bunch of peripherals), 32-bit DDR3 memory interface, plus a fairly
> large FPGA with enough block RAM to contain the maximum cylinder.  The
> calculations I've done should allow a new cylinder to be loaded from
> DRAM into the cylinder RAM in 4-8ms (I think with a few tricks I can
> keep it in the lower range).
>
> I've looked a quite a few Zynq SOMs (and have acquired quite a few for
> evaluation purposes).  I finally found one that's ~$200 (most of the
> others are in the $400-$1000+ range).  This SOM brings out most of the
> Zynq's I/Os (94 I/Os) in addition to having ethernet, USB, serial, SD
> card, etc. as well as 1GB of 32-bit DDR3 DRAM.  It also runs Linux which
> means that developing the SW is fairly straight forward.
>
> The next issue was how to emulate address marks.  The emulated drive
> will have a bit clock which is necessary for clocking out the data when
> reading (or out when writing).  The bit clock is always running (just
> like a "real" drive when spinning).  That will drive a counter (which
> represents which bit is under the emulated "head"), that counter (along
> with the head number) will be used to address the block RAM.  The
> counter is always running, so as to emulate the spinning disk.  The
> address marks are emulated by having a series of comparators (one for
> each possible sector).  They compare the bit counter with the value
> associated with the comparator, if there's a match then that signals an
> address mark.  It's bit more complicated because writing address marks
> (in the case of soft-sectors) has to be dealt with.
>
> The emulator is composed of 4 major components:
>
>  

[cctalk] IBM 38 on Facebook Marketplace

[Anders Nelson via cctalk]

I know nothing of what they're referring to, but just in case someone is
interested:

https://www.facebook.com/marketplace/item/1033559851065048


--
Anders Nelson
www.andersknelson.com

[cctalk] Re: Burroughs TD700

[Anders Nelson via cctalk]

Oof, those are pretty.
--
Anders Nelson
www.andersknelson.com


On Sun, Dec 3, 2023 at 3:09 PM Chris Coley via cctalk 
wrote:

> Why are you scrapping them?
> Are they generally complete?
>
> If there is enough to refurb into a unit I am interested.  I'm in Sequim,
> WA.
>
> Thanks
> Chris
>
>
> On Sun, Dec 3, 2023 at 12:01 PM Mike Stein via cctalk <
> cctalk@classiccmp.org>
> wrote:
>
> > Do any of you three or four TD700 owners out there need any parts? I'm
> > about to scrap a couple (in the Toronto area).
> >
> > m
> >
>

[cctalk] Re: Free to good home HP 7510a Photo Plotter - UK

[Anders Nelson via cctalk]

What an interesting device, I've never heard of such a thing.

How does it realize full-spectrum color if it uses primary color wheels?
Maybe by varying exposure time of each color?
--
Anders Nelson
www.andersknelson.com


On Thu, Nov 16, 2023 at 5:24 AM Dave Wade G4UGM via cctalk <
cctalk@classiccmp.org> wrote:

> Folks,
>
>
>
> Trying to reduce the weight in my loft and I would like to donate my HP
> Photoplotter to a good home.
>
> . Photos of the plotter and some sample plots are on my OneDrive here:-
>
>
>
> https://1drv.ms/f/s!Ag4BJfE5B3ongspXY7zySSZsDj-WMg
>
>
>
> It has both serial and IEEE interfaces and uses HPGL like the GP and Roland
> pen plotters.
>
> The plots on there are the samples built into the plotter taken on a Fuji
> XE-1 digital camera and are cropped because the Fuji does not have a full
> frame sensor.
>
> The tube is actually a white tube and the colours are generated by rotating
> colour filters.
>
> Its powered by a 68000 and you can see the various boards in the pictures.
>
>
>
> Dave
>
>
>
>
>
>

[cctalk] Re: Theory of operation of DEC H7441 regulator?

[Anders Nelson via cctalk]

This guy bucks.

I'm much less an analog guy, but that explanation was clear enough to make
sense of every stage. Very cool!

--
Anders Nelson
www.andersknelson.com

On Thu, Sep 28, 2023, 3:29 AM Brent Hilpert via cctalk <
cctalk@classiccmp.org> wrote:

> On 2023-Sep-27, at 9:01 PM, Tom Hunter via cctalk wrote:
> > The DEC H7441 regulator is a relatively complex circuit using 2 x 555
> > timers, 2 x LM301 op-amps, 2 x transformers and 2 inductors
> > I am struggling to understand how it is meant to work and was hoping to
> > find a maintenance manual for it.
> >
> > Could anyone with such a manual please help?
> >
> > Alternatively is there another explanation of the operation of this or
> > similar types of circuits?
> > The circuit implements a switch mode supply.
> >
> > One of the two 555 timers operates as an oscillator, the second I think
> > operates as a monoflop with the pulse length controlled via one of the
> > LM301s.
> > Overall the circuit seems very complex and while I understand parts of
> it,
> > other parts are mysterious.
> >
> > In particular the top left section around Q1/Q2/Q3 and T1/T2 and E3 is
> most
> > confusing.
> >
> > I did not find anything remotely similar in "The Art of Electronics" from
> > Horowitz & Winfield.
> >
> > The H7441 schematics are available from here:
> >
> >
> https://deramp.com/downloads/mfe_archive/011-Digital%20Equipment%20Corporation/08%20PDP-11/01%20PDP-1104-1134/02%20PDP-1134A%20Power%20Supply/H7441%20FMPS%20MP00271%20part-1%20(H7441).pdf
> >
> > Thanks for any help or suggested reading material.
>
>
>
> I'll take a stab at a brief description:
>
> The basic form is that of a switching inductive buck/step-down regulator.
>
> L1 is the main bucking inductor.
> D12 is the inductor discharge diode for the bucking operation.
> Q1 and Q2 are the main switching transistors, operating in parallel with
> T2 in their emitter circuits to balance current through the two transistors.
> Q3 is a driver stage for Q1,Q2.
> C11,L2,C16 are the main output filter.
>
> Fixed-frequency oscillator E1 triggers variable-width monostable E2 via Q6
> to create the PWM switching pulses.
> Q8 and associated form a constant-current source for the timing capacitor
> C10 of this PWM-monostable, to linearize the charge curve of the capacitor
> for better operation of the pulse-width timing.
>
> The switching pulses from the PWM-mono are amplified by Q5 to drive T1.
> T1 provides galvanic (voltage) isolation to shift the pulses up to the
> higher operating voltage of Q1,Q2,Q3.
> All base-drive energy for Q1 and Q2 is delivered through Q3 from T1, thus
> Q5 driving T1 must itself be a reasonably hefty driver.
> Excessive current through Q5 produces a V-drop across R10 which may turn
> on Q7 to take the PWM-mono into reset (E2.4=low).
> D7,D8,R3 clamp and sink reverse voltage/energy from the T1 secondary to
> avoid reverse breakdown/damage to Q1,Q2,Q3.
>
> Op-amp E4 is the voltage-sense amplifier for the main regulation feedback
> loop.
> D18 and associated provide the master reference voltage.
> An increase in the sensed +5 output voltage presented at -input E4.2
> relative to the reference voltage at +input E4.3 lowers the voltage into
> the PWM-mono control input E2.5 to shorten the ON-width of the switching
> pulses, and vice-versa for a decrease in the +5 output.
>
> Op-amp E3 is running open-loop to function as a comparator for
> over-current sense.
> R17,R18 are the current-sense resistors, placed here in the negative
> supply line of the +5 main output.
> If the current-induced voltage drop across R17,R18 becomes high enough, E3
> trips high, turning on Q7 to take the PWM-mono into reset.
> R19,R20 provide the counter-bias V that the R17,R18 V-drop must overcome
> to trip E3.
> E3 tripping high also turns on Q9 to short the reference voltage to GND at
> E4.3, to minimize the ON-width of the switching pulses.
>
> D20,D21,D22 form a crowbar for the +5 output.
> The crowbar tripping performs two actions: shorting the +5 output via D19,
> as well as shorting the switching pulses at the base of Q5 via D23 so the
> supply doesn't keep pumping energy into the shorted output.
>
> D2,Q4 and associated form a simple linear regulator for internal supply of
> ~ +12V to the control electronics.
> C7,D17,D25,C8 are a little charge pump driven off oscillator E1 to create
> a negative V supply for the op-amps E3,E4.
>
>

[cctalk] Re: FTGH: (3) Qualstar 1260 9 track tape drives pertec interface

[Anders Nelson via cctalk]

Yup, right there in /doc.
--
Anders Nelson
www.andersknelson.com


On Wed, Sep 27, 2023 at 2:58 PM Anders Nelson 
wrote:

> Chuck - is this the one?:
>
> https://github.com/Tubatstuff/Pertec-Interface-Tape-Controller
>
> =]
> --
> Anders Nelson
> www.andersknelson.com
>
>
> On Tue, Sep 26, 2023 at 11:13 AM Chuck Guzis via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> On 9/26/23 07:11, jim stephens via cctalk wrote:
>> > Overland data Pertec controllers, ISA, AT and PCI interfaces with
>> > utilities for the Pertec interface drives.
>>
>> I also posted plans and software for a Pertec tape controller using an
>> MCU with U SB or serial for comms and control.  Data is stored on mcriSD
>> card.  You can find details on Github.
>>
>> I run mine with a 32GB SD card; it works just fine.
>>
>> --Chuck
>>
>>
>>

[cctalk] Re: FTGH: (3) Qualstar 1260 9 track tape drives pertec interface

[Anders Nelson via cctalk]

Chuck - is this the one?:

https://github.com/Tubatstuff/Pertec-Interface-Tape-Controller

=]
--
Anders Nelson
www.andersknelson.com


On Tue, Sep 26, 2023 at 11:13 AM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:

> On 9/26/23 07:11, jim stephens via cctalk wrote:
> > Overland data Pertec controllers, ISA, AT and PCI interfaces with
> > utilities for the Pertec interface drives.
>
> I also posted plans and software for a Pertec tape controller using an
> MCU with U SB or serial for comms and control.  Data is stored on mcriSD
> card.  You can find details on Github.
>
> I run mine with a 32GB SD card; it works just fine.
>
> --Chuck
>
>
>

[cctalk] Re: Good C to FPGA/PLA compiler

[Anders Nelson via cctalk]

Oh, and Verilog all the way. I just can't with VHDL.

😆
--
Anders Nelson
www.andersknelson.com


On Fri, Sep 22, 2023 at 3:24 PM Anders Nelson 
wrote:

> Maybe these can help?:
>
>
> https://www.olimex.com/Products/FPGA/iCE40/iCE40HX1K-EVB/open-source-hardware,
> pair with
> https://www.olimex.com/Products/FPGA/iCE40/iCE40-DIO/open-source-hardware
>
> https://www.crowdsupply.com/1bitsquared/icebreaker-fpga
>
> I've personally used the iCE40 and iCE5LP in my larger designs,
> wonderfully capable and affordable devices.
>
> =]
> --
> Anders Nelson
> www.andersknelson.com
>
>
> On Fri, Sep 22, 2023 at 3:07 PM Chuck Guzis via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> On 9/22/23 11:34, emanuel stiebler via cctalk wrote:
>>
>> > There are still some 84pin chips out there(Altera & Xilinx). Sometimes
>> > they are pulls, or some 5V tolerant xilinx xc95l
>>
>> I still have a few 84 pin PLCC XC95108 5V CPLDs  Originally, I did a
>> tape controller design with one before Xilinx discontinued them.  I
>> figured that using a discontinued part was not the way forward, so I
>> dropped the project.   Xilinx did/does have its ISE design suite, which
>> is fairly easy to use.
>>
>> Eventually, it turned out that using a reasonably fast MCU with 5V
>> tolerant I/O worked just as well and avoided the "mystery in a chip" of
>> a CPLD.
>>
>> --Chuck
>>
>>

[cctalk] Re: Good C to FPGA/PLA compiler

[Anders Nelson via cctalk]

Maybe these can help?:

https://www.olimex.com/Products/FPGA/iCE40/iCE40HX1K-EVB/open-source-hardware,
pair with
https://www.olimex.com/Products/FPGA/iCE40/iCE40-DIO/open-source-hardware

https://www.crowdsupply.com/1bitsquared/icebreaker-fpga

I've personally used the iCE40 and iCE5LP in my larger designs, wonderfully
capable and affordable devices.

=]
--
Anders Nelson
www.andersknelson.com


On Fri, Sep 22, 2023 at 3:07 PM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:

> On 9/22/23 11:34, emanuel stiebler via cctalk wrote:
>
> > There are still some 84pin chips out there(Altera & Xilinx). Sometimes
> > they are pulls, or some 5V tolerant xilinx xc95l
>
> I still have a few 84 pin PLCC XC95108 5V CPLDs  Originally, I did a
> tape controller design with one before Xilinx discontinued them.  I
> figured that using a discontinued part was not the way forward, so I
> dropped the project.   Xilinx did/does have its ISE design suite, which
> is fairly easy to use.
>
> Eventually, it turned out that using a reasonably fast MCU with 5V
> tolerant I/O worked just as well and avoided the "mystery in a chip" of
> a CPLD.
>
> --Chuck
>
>

[cctalk] Re: 8" DSDD to USB MSD?

[Anders Nelson via cctalk]

I agree, and that generic USB FDC is already available:

https://github.com/dhansel/ArduinoFDC

If I can simply select 5 1/4 floppy mode and it'll work with an 8" disk, I
guess I don't need anything else?

On Fri, Sep 8, 2023, 6:20 PM Fred Cisin via cctalk 
wrote:

> >>>> but presents itself to an OS as a Mass Storage Device (block device).
>
> >> Anders, for what practical purpose would you do that?
> >> It’s not like there’s so many 8 inch floppies around to make it
> feasible.
> >> You would have to have a LOT of intelligence in the Usb interface due to
> >> the different physical formats let alone the software formats.
> >> It would be difficult.
>
> On Fri, 8 Sep 2023, Anders Nelson via cctalk wrote:
> > Hi Wayne,
> > For sure the controller would have to do a lot more, but I know firmware
> > pretty well and BIOS/ancient OSes not at all! 😅
>
> It would still be handy to have a USB device that operates as a "normal"
> fully functional FDC.
> It would make it possible to add floppies to devices without them, and/or
> add more or different floppies to devices that do have them.
> The basic software for it could be in flash RAM in the same USB device.
>
> Source code for the IBM PC BIOS was published.
> For floppies, you need Int13h, and there is a table of parameters pointed
> to by Int1Eh.
>
> Handling formats other than PC, auch as CP/M, P-System, TRSDOS, MS
> Stand-Alone BASIC, Mac "1.44MB", etc. would require additional code.
>
>
> --
> Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: 8" DSDD to USB MSD?

[Anders Nelson via cctalk]

Hi Chuck,

The drive is a Qume Qumetrak 242 so I assume soft sector? I'm open to
correction.

On Fri, Sep 8, 2023, 4:15 PM Fred Cisin via cctalk 
wrote:

> On Fri, 8 Sep 2023, Anders Nelson via cctalk wrote:
> > Hi all,
> > I just bought a very clean, DSDD 8" disk drive off eBay and it has a 50p
> > connector which I guess is the common Shugart type? I also found a 50p->
> > 34p adaptor PCB design someone documented online.
>
> very few of the lines need to be rearraanged, so you can just twist a few
> wires in a cable.  One exception is that if you need the TG43 signal for
> writing, then you will need additional circuitry.
>
> > I haven't delved much into floppy formats (high level or low level) but
> I'm
> > somewhat familiar with filesystems from FAT12. My ultimate goal is to
> > create an open-source USB adaptor that reads/writes the contents of an 8"
> > disk but presents itself to an OS as a Mass Storage Device (block
> device).
> > Is such a thing possible?
>
> Sure.  Ine the very early days of external USB floppies, there existed a
> rare few in which the circuitry was a general purpose FDC.  All currently
> produced ones are locked in to only supporting a couple of PC 3.5"
> formats.  Look for "mode 3", which is support for the NEC format, which is
> compatible with 8" formats, IFF you can modify the hardware to work.
>
> > I once created a terrible custom format for storing data on a flash chip
> > which required no low-level format, but I expect a magnetic disk needs
> > headers/trailers to know when a track starts/stops so it can skip around.
>
> Yes.  It is called "IBM format", but that is confusing, since it is
> talking about the track structure that IBM designed (3740?), NOT about IBM
> PC (which does use that structure)
>
> > I checked out the KyroFlux website and it seems there are dozens of
> formats
> > that were used for 8" disks - is there a favorite format among the
> > community that allows full use of a 1.2MB 8" disk?
>
> Not everybody will agree, but, . . .
> NEC modified their 3.5" drives to be 360RPM, same as their 5.25" 1.2M
> drives, and 8" drives.  Thus, they used the same format on all three
> sizes!
>
> http://www.xenosoft.com/fmts.html#8
>
>
> --
> Grumpy Ol' Fred ci...@xenosoft.com
>

[cctalk] Re: 8" DSDD to USB MSD?

[Anders Nelson via cctalk]

Hi Wayne,

For sure the controller would have to do a lot more, but I know firmware
pretty well and BIOS/ancient OSes not at all! 😅

On Fri, Sep 8, 2023, 4:22 PM Wayne S via cctalk 
wrote:

>
>
> Sent from my iPhone
>
> > On Sep 8, 2023, at 13:16, Wayne S  wrote:
> >
> >> but presents itself to an OS as a Mass Storage Device (block device).
>
> Anders, for what practical purpose would you do that?
> It’s not like there’s so many 8 inch floppies around to make it feasible.
> You would have to have a LOT of intelligence in the Usb interface due to
> the different physical formats let alone the software formats.
> It would be difficult.
>
>
>

[cctalk] 8" DSDD to USB MSD?

[Anders Nelson via cctalk]

Hi all,

I just bought a very clean, DSDD 8" disk drive off eBay and it has a 50p
connector which I guess is the common Shugart type? I also found a 50p->
34p adaptor PCB design someone documented online.

I haven't delved much into floppy formats (high level or low level) but I'm
somewhat familiar with filesystems from FAT12. My ultimate goal is to
create an open-source USB adaptor that reads/writes the contents of an 8"
disk but presents itself to an OS as a Mass Storage Device (block device).
Is such a thing possible?

I once created a terrible custom format for storing data on a flash chip
which required no low-level format, but I expect a magnetic disk needs
headers/trailers to know when a track starts/stops so it can skip around.

I checked out the KyroFlux website and it seems there are dozens of formats
that were used for 8" disks - is there a favorite format among the
community that allows full use of a 1.2MB 8" disk?

Any pointers are appreciated!

Anders
www.andersknelson.com

[cctalk] Re: Source for NEW (unused) punch tape

[Anders Nelson via cctalk]

This is an awesome idea, please make it. How great would it be to load a
receipt-paper roll (made of heavier stock of course), lase the holes and
pass the paper over a vacuum slot to suck the chads.

I was trying to come up with a mostly 3d-printable, cam-driven punch myself
but of course it will never get done.

Happy to provide any hardware/embedded help if wanted!

--
Anders Nelson


On Mon, Jun 5, 2023 at 2:19 PM Robotguy via cctalk 
wrote:

> For various reasons (including, but not limited to, insanity and
> obsessiveness*) I am building a diode laser based tape punch. It's not
> specifically for a classic comp, but I'd like to stick with standard format
> so that it'd be useful for making custom tapes for members in the future. I
> will probably need to make dozens of tapes so using actual, vintage rolls
> is out of the question. Does anyone know if 1" tape is used for anything
> else and where I might find some new? Otherwise I may have to add
> paper-slitter to my project list and make my own.
>
>
>
>
> *I've had the idea of a lost-media ARG stuck in my head for years.
>

[cctalk] Re: Late '70s DEC manual covers [niche!]

[Anders Nelson via cctalk]

Wow, beautiful! Any chance I could get a poster/high-quality print of your
4-up artwork?

=]
--
Anders Nelson


On Sat, Feb 11, 2023 at 1:30 PM Paul Koning via cctalk <
cctalk@classiccmp.org> wrote:

>
>
> > On Feb 11, 2023, at 4:43 AM, Paul Flo Williams via cctalk <
> cctalk@classiccmp.org> wrote:
> >
> > On Fri, 10 Feb 2023 22:33:03 +
> > Paul Flo Williams via cctalk  wrote:
> >
> >> During lockdown I was having some fun redrawing old DEC manual covers
> >> with Inkscape, specifically terminal and printer manuals from the late
> >> 1970s. I've attached a montage of four that I printed out so I could
> >> stick it on the wall. I'm aware I may be the only person, even here,
> >> who finds them attractively simple and coloured in such a definably
> >> 1970s way.
> >
> > Here are the four images:
> >
> > https://vt100.net/tmp/vtm.small.png
> >
> > Thanks for alerting me to the retro rules, Lawrence!
> >
> > Paul
>
> Nice!
>
> Vaguely related: many years ago I created a font file for the lettering
> found on the earlier PDP-11 handbooks.  I included some letters that didn't
> appear on those covers, guessing at what one might look like (the letter
> "x" for example).
>
> https://github.com/pkoning2/decstuff/tree/master/fonts
>
> paul
>
>

[cctalk] Re: CD-R, DVD-R media available

[Anders Nelson via cctalk]

Does anyone here know which brands/lines had the best longevity?

--
Anders Nelson


On Wed, Feb 1, 2023 at 11:28 AM David Barto via cctalk <
cctalk@classiccmp.org> wrote:

> 100’s of CD-R, Sony, TDK, and FujiFilm.
> 25-30 DVD-R Sony and TDK
>
> And CD cases sufficient to hold all the disks
>
> Heavy, available for the cost of shipping.
> I’m in San Diego, so local delivery is possible.
>
> David
>
>

[cctalk] Re: reset "pulse" stretcher need

[Anders Nelson via cctalk]

That latch idea is neat! Both should work a treat.

Anders

On Wed, Dec 7, 2022, 9:44 AM Patrick Finnegan via cctalk <
cctalk@classiccmp.org> wrote:

> On Wed, Dec 7, 2022 at 12:40 AM Jim Brain via cctalk <
> cctalk@classiccmp.org>
> wrote:
>
> > This might be a bit off topic, so forgive me if so.
> >
> > The issue is a 24VAC motor with one connection to 24VAC and the other
> > gated via two switches.  The first switch is a momentary one and the
> > second is in parallel and connected to the motor.  A long enough
> > momentary depression on the first switch actuates the electric motor
> > enough to close the second switch, which then stays closed for 1
> > revolution.
> >
> > The problem is that a quick enough press and release of the first switch
> > does not allow the motor to move far enough to close the second switch.
> >
> > Given the configuration, my general plan was a small one shot timer
> > circuit that energized when the switch was initially depressed and then
> > closed a relay in parallel with the first 2 switches, with a time period
> > that was 1/10 to 1/2 the time of the motor revolution. a quick close and
> > release of the first switch would start the timer, which would then
> > close the parallel switch and then open it a short time later, and then
> > the motor switch, which would still be closed, could signal the end of
> > the cycle.
> >
>
> My two thoughts would be:
>
> 1) A 555-timer in one-shot mode
> 2) An S-R latch at is set by the push button, and cleared by 2nd switch
>
> Pat
>

[cctalk] Re: REPLICA Cromemco Cyclops Camera

[Anders Nelson via cctalk]

Today I learned, thank you!

--
Anders Nelson


On Mon, Dec 5, 2022 at 1:00 PM William Sudbrink 
wrote:

> Senior moment below… should (obviously) be just _*above*_ visible.
>
>
>
> *From:* William Sudbrink [mailto:wh.sudbr...@verizon.net]
> *Sent:* Monday, December 05, 2022 12:54 PM
> *To:* 'Anders Nelson' ; 'General Discussion:
> On-Topic and Off-Topic Posts' 
> *Subject:* RE: [cctalk] REPLICA Cromemco Cyclops Camera
>
>
>
> The image sensor is a MOSTEK MK4008P-9 or an AMI S4008-9.  Cromemco used
> both.  They removed the lid and added a glass cover, but the cover is not
> necessary.  I have operated several cameras with no cover.  If you scroll
> up to the top of the page, you will see pictures of the chips.  The memory
> cells in the chips are three transistor design, allowing non-destructive
> reads.  The device repeatedly reads the cell array, watching as they fade
> out due to charge leakage caused by light hitting the cell.  Interestingly,
> the light sensitive component in the cell is not the capacitor, but rather
> the transistor linked to ground.  The transistor is sensitive to visible
> light but is even more sensitive to infrared (just below visible).
>
>
>
> Bill
>
>
>
> *From:* Anders Nelson [mailto:anders.k.nel...@gmail.com
> ]
> *Sent:* Monday, December 05, 2022 12:31 PM
> *To:* General Discussion: On-Topic and Off-Topic Posts <
> cctalk@classiccmp.org>
> *Cc:* William Sudbrink 
> *Subject:* Re: [cctalk] REPLICA Cromemco Cyclops Camera
>
>
>
> Was the image sensor a CCD/PD imager or  clever use of a memory chip with
> a window?
>
>
>
> On Mon, Dec 5, 2022, 10:23 AM William Sudbrink via cctalk <
> cctalk@classiccmp.org> wrote:
>
> Sorry to spam the list, but I find myself in need of some holiday cash (or
> positive PayPal balance, anyway) so I am offering a REPLICA Cromemco
> Cyclops
> Camera for sale.  This is ONLY THE CAMERA.  You will need to have your own
> Cyclops interface board set or build an XYZ scope interface as in the
> manual:
>
>
>
>
> https://www.autometer.de/unix4fun/z80pack/ftp/cromemco/Cromemco%2088%20ACC%2
> 0Manual.pdf
>
>
>
> This will be the camera I demonstrated at 2018 VCF East.  All three circuit
> boards are clearly labeled REPLICA in the copper layer.  Details of the
> construction and other photographs are on my web page:
>
>
>
> http://wsudbrink.dyndns.org:8080/cyclops/index.html#Cromemco
>
>
>
> I would much rather sell it here to someone who clearly understands what
> they are getting, rather than dealing with ebay.  I will also include a
> pair
> of REPLICA side panels (made from measurements of an original) that I had
> made last year.  I would be happy to zoom with the buyer and demonstrate
> the
> camera in operation.
>
>
>
> Email me directly if interested.
>
>
>
> Thanks,
>
> Bill S.
>
>
>
> --
> This email has been checked for viruses by Avast antivirus software.
> www.avast.com
>
>
>
> 
> Virus-free.www.avast.com
> 
> <#m_-178727210965869595_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>

[cctalk] Re: REPLICA Cromemco Cyclops Camera

[Anders Nelson via cctalk]

Was the image sensor a CCD/PD imager or  clever use of a memory chip with a
window?

On Mon, Dec 5, 2022, 10:23 AM William Sudbrink via cctalk <
cctalk@classiccmp.org> wrote:

> Sorry to spam the list, but I find myself in need of some holiday cash (or
> positive PayPal balance, anyway) so I am offering a REPLICA Cromemco
> Cyclops
> Camera for sale.  This is ONLY THE CAMERA.  You will need to have your own
> Cyclops interface board set or build an XYZ scope interface as in the
> manual:
>
>
>
>
> https://www.autometer.de/unix4fun/z80pack/ftp/cromemco/Cromemco%2088%20ACC%2
> 0Manual.pdf
> 
>
>
>
> This will be the camera I demonstrated at 2018 VCF East.  All three circuit
> boards are clearly labeled REPLICA in the copper layer.  Details of the
> construction and other photographs are on my web page:
>
>
>
> http://wsudbrink.dyndns.org:8080/cyclops/index.html#Cromemco
>
>
>
> I would much rather sell it here to someone who clearly understands what
> they are getting, rather than dealing with ebay.  I will also include a
> pair
> of REPLICA side panels (made from measurements of an original) that I had
> made last year.  I would be happy to zoom with the buyer and demonstrate
> the
> camera in operation.
>
>
>
> Email me directly if interested.
>
>
>
> Thanks,
>
> Bill S.
>
>
>
> --
> This email has been checked for viruses by Avast antivirus software.
> www.avast.com
>

[cctalk] Re: Pertec controller; was: anybody need 1/2" tape drives?

[Anders Nelson via cctalk]

*ESP32 = Xtensa core

https://dl.espressif.com/github_assets/espressif/xtensa-isa-doc/releases/download/latest/Xtensa.pdf

On Thu, Dec 1, 2022, 2:59 PM David Gesswein via cctalk <
cctalk@classiccmp.org> wrote:

> On Wed, Nov 30, 2022 at 04:43:08PM -0800, Chuck Guzis wrote:
> > On 11/30/22 14:45, Eric Moore via cctalk wrote:
> > > I have a kennedy 9100 with an unformatted pertec interface that I would
> > > love to use for imaging tapes from my AS/400
> > >
> > > It seems like strapping a logic analyzer to the read connector, and an
> > > arduino on the command connector, may be fairly easily done? Has anyone
> > > done that?
> >
> > I have to confess that I've never understood the Arduino thing.  It
> > seems to be limiting the functionality of an MCU in the name of
> convenience.
> >
>
> It also gives portability across manufactures for the simple stuff and
> a consistant though not the most feature full enviornment that is the same
> for each board. You can use the low level functions of the chips if you
> want
> but then it won't be portable.  Also a good amount of how to do X with it
> online.
>
> I use it for that reason. Good for small projects.
> I've used manufacturer specific enviornments in the past but see no need
> to.
>
> Last project was some remote sensors using ESP32. $8 for the board. Arm
> processor.
>

[cctalk] Re: Inline Serial Device?

[Anders Nelson via cctalk]

I bet NN/AI would be helpful with data recovery - if we can model certain
common failure modes with those old drive heads we could infer what the
data should have been...

--
Anders Nelson


On Sat, Nov 12, 2022 at 1:05 PM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:

> On 11/12/22 09:41, Ethan Dicks via cctalk wrote:
>
> >
> > Yeah, the 555 is extremely simple and is well known and is fairly
> > cheap, simple MCUs are simple (and cheap) even if they aren't 100%
> > deterministic like a chip with 20-30 transistors.  There's economic
> > advantage in flexibility.
>
> There's also efficiency in mass-produced numbers.  There are several
> Chinese MCUs that go for less than USD$0.10 in low quantities. I think
> the bottom end a couple of years ago was about USD$0.03.  At that price
> point, you have to wonder if some of that isn't the packaging (tape
> reel) cost.
>
> There are far more MCUs made today than 555s, if that's any indication.
>
> And some of the newest ones feature neural net hardware (e.g. MAX78000).
>  Do that with your 555s!
>
> I, for one, welcome our robot overlords.
>
> --Chuck
>
>
>

[cctalk] Re: Inline Serial Device?

[Anders Nelson via cctalk]

I can probably build firmware to this for you and assemble a list of OTS
parts you can connect together in a day or two - what string do you want to
trigger on? Parameters, 8N1? RTS/CTS? Voltage at RS-232 or TTL level?

OTS parts cost maybe $30?

Source: am firmware engineer at Peloton (and still employed, wheee).

--
Anders Nelson


On Sat, Nov 12, 2022 at 12:27 PM Peter Corlett via cctalk <
cctalk@classiccmp.org> wrote:

> On Sat, Nov 12, 2022 at 10:28:09AM +, Tony Duell via cctalk wrote:
> [...]
> > The other day I saw a product with a flashing LED, the flash rate was set
> > with a knob. Yes, a microcontroller with a pot connected to an analogue
> > input and LED hung off an output port. This is the sort of thing I'd do
> > with a couple of transistors or an NE555 depending on which turned up in
> > the junk box first.
>
> Farnell Nederland is quoting me €1.06 (+21% VAT) for the cheapest brand of
> 555 in stock. Their search won't let me find the cheapest microcontroller
> without drilling down further, but an 8 pin AVR is €0.88. That's single
> item
> quantities in DIP packaging, as is typical for small home projects. The 555
> will also need a capacitor for its RC timer circuit which is another few
> tens of cents. And that's why people use microcontrollers to blink LEDs.
>
> The MCU in the Pi Pico is also well under a euro if you buy a reel of 3,400
> of them. That's probably a few too many for an average hobbyist :)
>
>

[cctalk] Bubble Memory

[Anders Nelson via cctalk]

On eBay, 10pcs for $75: https://www.ebay.com/itm/394216367144

=]
--
Anders Nelson

[cctalk] Re: Large private collections

[Anders Nelson via cctalk]

I went to the Large Scale Systems Museum in New Kensington, PA (USA) a few
weeks ago. I've never seen such a large collection outside of the CHM in
Mountain View, CA (USA) but I've also only seen three collections haha.

The LSSM's main area was amazing (and most items are operational) but the
systems in their off-site storage area blew my mind...

Dave the curator is an endless well of knowledge, too. I highly recommend a
visit.

=]

On Tue, Oct 18, 2022, 12:03 PM Bill Degnan via cctalk 
wrote:

> I have seen system source both the museum part and the warehouse in the
> back.  The rhode island.museum and warehouse is probably larger.  Not that
> system source is not substantial.
> Bill
>
> On Tue, Oct 18, 2022, 9:26 AM Ethan O'Toole via cctalk <
> cctalk@classiccmp.org> wrote:
>
> > > I suspect Jim Austin has one of the largest collections that's publicly
> > > documented...
> > > https://www.computermuseum.org.uk/
> > > .. but many are very private about what they own
> > > Dave
> >
> > Indeed! Looking down their list it's quite impressive but I think System
> > Source has them beat. I don't see a list of systems on the system source
> > website though so I have to go from memory and what I know.
> >
> > Not sure how big the collections are behind the scenes at Living Computer
> > Museum, CHM or that place down in Georgia. And who knows how many other
> > Computer Reset Warehouses are out there that we don't know about.
> >
> > --
> > : Ethan O'Toole
> >
> >
> >
>

[cctalk] Re: 11/45 and 11/34 Taken!

[Anders Nelson via cctalk]

No if only I had skipped my office meeting this morning!
--
Anders


On Thu, Sep 22, 2022 at 11:32 AM Kevin McQuiggin via cctalk <
cctalk@classiccmp.org> wrote:

> Hi All:
>
> I’m pleased to report that my 11/45 and 11/34 which were in need of a new
> home have been taken by another collector here in BC.  They will be off to
> a very good home!
>
> Thanks for reading my post.
>
> Kevin
>
>

Re: Xerox 800 Word Processor 1974 promo film

[Anders Nelson via cctalk]

Very cool!
--
Anders Nelson

On Sat, Jul 2, 2022 at 12:32 PM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:

> On 7/2/22 08:44, Nigel Johnson Ham via cctalk wrote:
> > I remember hearing it in the UK before I emigrated to Canada - maybe it
> > was  a regional thing.
> >
> > I certainly saw a British telephone in one of the shots!
>
> J. Arthur Rank and his big gong.  Veddy British!
>
> --Chuck
>
>

Re: Cctalk subscription disabled

[Anders Nelson via cctalk]

Yes I've been getting the same "excessive bounces" emails as well!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Wed, May 11, 2022 at 8:17 AM jwest--- via cctalk 
wrote:

> Yes, Adrian is correct – known for some time but my time/focus has been
> elsewhere. Addressed yesterday, should make gmail less fussy.
>
>
>
> J
>
>
>
> From: cctalk  On Behalf Of Tom Hunter
> Sent: Wednesday, May 11, 2022 7:06 AM
> To: Adrian Stoness ; cctalk-ow...@classiccmp.org
> Cc: General Discussion: On-Topic and Off-Topic Posts <
> cctalk@classiccmp.org>
> Subject: Re: Cctalk subscription disabled
>
>
>
> I wonder if this problem is related to DMARC anti-spam.
>
> Maybe the following would help the list admin:
>
>
>
> https://wiki.list.org/DEV/DMARC
>
> https://dmarc.org/wiki/FAQ
>
>
>
> Thanks
>
> Tom
>
>
>
> On Wed, May 11, 2022 at 2:26 PM Adrian Stoness   > wrote:
>
> gmail is causing it
>
>
>
> On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk <
> cctalk@classiccmp.org  > wrote:
>
> I didn't receive any cctalk messages for a few days, so I checked my Spam
> folder (empty) and then the archive which had several new messages I
> haven't seen. I then checked my cctalk membership configuration.
> Surprisingly "Mail delivery" was disabled.
>
> Some time ago I received a few emails from the list server about "excessive
> bounces" saying that I should simply reply to the email otherwise my
> subscription would be disabled. I replied and didn't think too much about
> it. This time I got no "excessive bounces" email but my subscription got
> disabled.
>
> I got an otherwise reliable @gmail.com   email address.
> Does anyone else here
> have problems with this? Is there some way of preventing this from
> happening?
>
> Thanks
> Tom
>
>

Glass memory?

[Anders Nelson via cctalk]

Hey all, found this on eBay:

https://www.ebay.com/itm/Corning-Glass-memory-/125087612899

I can't find any info on it - was it some kind of delay-line or magnetic
laminate stack?

Interesting!

DEC HDD heads?

[Anders Nelson via cctalk]

Dunno if this is useful for anyone but the price seems right:

https://www.ebay.com/itm/Qty-8-Cdc-Dec-Disk-Head-Heads-75010109-75010101-/255306991030

Re: tamayatech let down

[Anders Nelson via cctalk]

You can always call the credit card company and dispute the charge.

--
Anders


On Mon, Dec 20, 2021 at 9:33 PM Jacob Ritorto via cctalk <
cctalk@classiccmp.org> wrote:

> I think I should pass on my experience as a warning to others.
>
> I googled around for a particular PDP-11 board I needed and tamayatech.com
> was a hit, with "buy now" option and condition: refurbished.  Seemed
> convincing and the price was in the sane ballpark.   So I bought it, paid
> through their ecommerce routine, etc.
>
> Sent a mail thanking them and asking if it would be despatched soon as I
> had work time off in the coming week..  No reply.
>
> Waited a week and telephoned their phone number from the purchase
> confirmation email.  No answer.  Left message.
>
> Several (well over ten) repeated email and phone contact attempts through
> the last months (this began early November) to no avail.  There has been
> absolutely no response.  So my conclusion: it looks as though they took my
> credit card and never shipped it, then just ignored me. I hope the fellow's
> okay but feel quite thoroughly ripped off.
>
> So 'buyer' beware.
>
> Interestingly their SEO is rather well maintained and punching DEC part
> numbers into Google, etc. often results in a hit to their site.  So they're
> at least keeping that part of the business updated.
>
> Anybody else with similar experience?  Any way to rectify the situation?
>
> thx
> jake
>

Re: OT, assembly houses in the US

[Anders Nelson via cctalk]

I just used www.pcbassemblyexpress dot com to do a small assembly run for
me. Online quoting was nice. Like all affordable fab/assembly brokers,
their turnaround time was off by a week or so. Much better pricing than
most places I saw!

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Tue, Dec 14, 2021 at 2:35 PM Jonathan Chapman via cctalk <
cctalk@classiccmp.org> wrote:

> We do both THT and SMD in prototype and production quantities here at
> Glitch Works, LLC. We're located in central VA. You can email me off-list
> if interested.
>
> Thanks,
> Jonathan
>
> ‐‐‐ Original Message ‐‐‐
>
> On Tuesday, December 14th, 2021 at 14:23, emanuel stiebler via cctalk <
> cctalk@classiccmp.org> wrote:
>
> > Hi all,
> >
> > where do you guys go for assembly of your boards, when you replace old
> >
> > stuff?
> >
> > Not too many places like THT anymore, and getting ridiculously expensive
> >
> > lately.
> >
> > Any recommendations?
>

Re: DEC HP sgi ibm and misc for sale

[Anders Nelson via cctalk]

First, you're hilarious. Second, can you link some photos of those
Televideo terminals?

You have quite the collection!

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Tue, Jun 29, 2021 at 7:43 AM devin davison via cctalk <
cctalk@classiccmp.org> wrote:

> I am making room to work on my pdp 11 and mainframe computers. The
> following things are for sale :
>
> 3 Dec decmate computers with kb and monitor. Partway loads into the WP os
> but the floppy is bad, and i dont have more
>
> Sgi tezro
>
> Hp 9000 desktop for hp -ux with cables
>
> Working microvax 3100 with install of vms. Vt terminal availible for sale
> too to go with it.
>
> Hp 9000 for basic. Was used with test insturments like volt meters, relay
> controllers  hpib etc for process control.
> Many hp keyboards with chicklet keys availible for this system
>
> Tandy vgm 300 monitor
>
> Enough crt monitors to sink a boat.  Nec, viewsonic, ibm, etc.
>
> S100 bus computer chassis with backplane, power supply and proto boards.
>
> A single S100 backplane
>
> Isa /pci single board computer backplanes
>
> Isa 486 and pentium single board computers. Works standalone or with
> previously mentioned backplane
>
> Rackmount 68k vme bus motorolla computer with floppy, hard drive and proto
> boards.
>
> (Must be sold together will not seperate) books for like every version of
> irix apple early windows maya, power animator, discreet, etc. Sgi install
> cd sets. Sgi power animator cd. Studio paint. Misc hotmix cd's.
>
> Trs 80 model 3. No keyboard. Posts, bad floppy drive hangs up boot. Unplug
> it and it works. Big / heavy.
>
> Dec alphastation 255 computers x3
> I had vms on them at some point.
>
> Wyse dumb terminal in original box
>
> Many televideo dumb terminals
>
> Ibm bladecenter h chassis with misc blades and spare fans etc. Shipping
> will be expensive.
>
> Hp 50mhz dual trace scope 54200a.
>
> Working apple mac plus with kb and external 20 mb hard drive. No battery
> damage. Clean. Boots. Runs.
>
> Im sure to find more to list. Send some offers my way and ill ship it out.
>
> Located in melbourne fl.
>
> https://mastodon.technology/@mrbill0/media?
>
> Most of my stuff is on my mastadon gallery, welcome to scroll through. I
> can provide pictures of said machines upon request, too much to take
> pictures of right now though.
>
>
>
> --Devin D.
>

Re: IBM cpu tear down

[Anders Nelson via cctalk]

Welp, there went an hour of billable time...

=D
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Thu, Apr 1, 2021 at 12:56 AM D. Resor via cctalk 
wrote:

> I thought I had seen this before...
>
> EEVblog teardown of a ES9000 processor.
>
> https://youtu.be/xQ3oJlt4GrI
>
> Don Resor
> N6KAW
>
> -Original Message-
> From: cctalk  On Behalf Of Kevin Lee via
> cctalk
> Sent: Wednesday, March 31, 2021 9:15 PM
> To: cctalk@classiccmp.org
> Subject: IBM cpu tear down
>
> https://www.righto.com/2021/03/logic-chip-teardown-from-vintage-ibm.html
>
> Enjoy.
>
>

Re: PIC programmers? More generic programmer? Port?

[Anders Nelson via cctalk]

I was a field application engineer for Microchip from 2008-2011, making
POCs for big name customers in the bay area using 8, 16 and 32-bit PICs.

You will likely find that Microchip support is awful, even if their
products are pretty neat. There was an Arduino port for PICs called
"ChipKit" but I don't know if that's still being developed.

The PicKit 3 is decent, if pretty slow. The ICD3 and later versions are
good. MPLAB X is excellent IMO. I should still hold a design partner
discount so if you want to get some tools, contact me offline and I'll see
if I can save you some money.

That all said, I'm a huge fan of the STM32 ARM devices and the community is
nearly as good as Nordic, and what Atmel used to be before it was acquired
by Microchip.

--
Anders Nelson


On Wed, Mar 3, 2021 at 4:26 PM Chuck Guzis via cctalk 
wrote:

> On 3/3/21 10:47 AM, Dennis Boone via cctalk wrote:
> >  > Any gotchas with the PICKit-3 clones out there? I have the feeling
> >  > that sticking with PIC would be better than trying to port to
> >  > Arduino, and imagine that as things continue to age there will be
> >  > more applications for interfaces. Any better but still cheapish
> >  > alternatives for programming?
> >
> > IIRC the PK-3 doesn't get any new device support at this point.
> > Existing stuff continues to work.  Depending on the nature of the
> > devices you might want to use in the future, it might be worth
> > considering a PK-4.
>
> I've used a PK-2 on PIC32MX devices.  I used MPLAB for a time, but
> OpenOCD also supports it.   After all, it's JTAG, sort of.
>
> What chips specifically?  On the PIC12 through PIC18 devices, I used the
> JDM cheapie with PonyProg.   Of course, you need a real serial port--I
> don't know of a USB one will work.
>
> Personally, you might find it more interesting to go with some of the
> STM32 ARM Cortex MCUs.  Many are 5V tolerant and will probably be around
> for a long time.   There's even an Arduino suite or two for the low-end
> ones.
>
> --Chuck
>
>
>
>

Re: IBM and Calcomp gear rescue in Toronto area

[Anders Nelson via cctalk]

Ugh, those tape drives are gorgeous.

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Thu, Aug 20, 2020 at 1:10 PM John Foust via cctalk 
wrote:

>
> <
> https://www.reddit.com/r/vintagecomputing/comments/id17d2/i_need_vintagecomputings_help_in_the_early_1980s/
> >
> https://www.reddit.com/r/vintagecomputing/comments/id17d2/i_need_vintagecomputings_help_in_the_early_1980s/
>
> IBM 29 card punch
> IBM 2501 card reader
> IBM 3420 magnetic tape unit
> IBM 3803 tape control unit
> Calcomp 663 plotter
> Calcomp 770 plotter tape storage
> Remington tabulator
> and some relatively more modern printers, two daisywheels and a laser
> printer.
>
>

Re: PDP-8/A transformer hum

[Anders Nelson via cctalk]

Interesting, good to know!
--
Anders Nelson


On Tue, Jun 9, 2020 at 1:04 PM Ethan Dicks via cctalk 
wrote:

> On Tue, Jun 9, 2020 at 10:46 AM Jon Elson via cctalk
>  wrote:
> > On 06/09/2020 09:27 AM, Anders Nelson via cctalk wrote:
> > > Related question: Is there any reason, other than historical accuracy
> and
> > > cost, to not replace the power supplies in vintage computers with
> modern
> > > switching power supplies?
> > >
> > The old discrete transistor machines often used fairly odd
> > voltages, not like 5V and 12V.
>
> DEC's transistorized machines used +10V and -15V supply rails for the
> logic, and some other large voltage (+28V?) for the core.
>
> Later machines still used odd voltages.  Lamp-based PDP-8 front panels
> used voltages like +8V, and later core was IIRC +20V.
>
> There are a couple versions of the PDP-8/a PSU, for core memory and
> for MOS memory.  MOS memory is standard 1970s triple-voltage stuff
> (4096s and 4116s) but they pull a lot of +12V compared to later
> machines.
>
> It's often easier to just fix the old PSUs than replace them.  At
> least linear supplies aren't so hard to debug.
>
> -ethan
>

Re: PDP-8/A transformer hum

[Anders Nelson via cctalk]

Related question: Is there any reason, other than historical accuracy and
cost, to not replace the power supplies in vintage computers with modern
switching power supplies?

--
Anders Nelson


On Tue, Jun 9, 2020 at 10:19 AM Paul Koning via cctalk <
cctalk@classiccmp.org> wrote:

>
>
> > On Jun 9, 2020, at 2:59 AM, Josh Dersch via cctalk <
> cctalk@classiccmp.org> wrote:
> >
> > Hi all --
> >
> > I'm working on a PDP-8/A I picked up at VCF West last summer.  After a
> lot
> > of cleaning and some power supply repair it's showing signs of life (CPU
> > seems to be at least minimally functional, core memory is going to need
> > some debugging.)
> >
> > The transformer in the power supply is humming quite loudly, however, and
> > I'm curious if this is normal for the 8/A (or is typical for an 8/A of
> this
> > vintage).  I'm used to the supplies in various other DEC machines not
> being
> > exactly silent but this is a rather severe 60Hz buzz that you can clearly
> > hear over the fans when the machine is in operation.
>
> Assuming these are traditional transformers with laminated sheet iron
> cores, check if the rivets or screws holding the laminations together are
> loose.  If yes, tighten or replace the fastener.
>
> paul
>
>

Re: DIY Paper Tape Punch - Mechanism diagram?

[Anders Nelson via cctalk]

Wow, what a response! Really appreciate the docs and first-hand experience,
this is super helpful.

I'm also floored by the complexity of that Roytron punch! Looks like it
contains around one hundred separate parts. I'm convinced the punch parts
will have to be precision metal so while that's not quite "DIY" it might
still be a reasonable bit to CNC, mill or water-jet cut.

It also looks like that punch has an escapement mechanism of some sort?
Seems like a simple way to keep regular spacing, but if course more parts
to buy from McMaster Carr or whatever.

Question: did all tapes have indexing holes separate from the drive
sprocket holes? Also is there a source for tape with sprocket holes anymore?

I also like the idea of using a LASER cutter and a rotating platform like
they use to engrave drinking glasses. Add a light vacuum nozzle under the
tape past the cutting surface to suck up the chads, and perhaps make the
cutting surface wheel with of rows of thin plates as the cutting surface,
similar to the thin honeycomb cutting beds of typical LASER cutters. I
imagine it'd take an awfully long time to use a traditional core XY cutter
versus a galvo-mirror cutter.

I have some experience cutting planar items in LASER cutters but little
experience beyond basic principles regarding machining/modeling/rotating
LASER stuff.

On Fri, May 1, 2020, 11:32 AM John Foust via cctalk 
wrote:

> At 07:18 AM 5/1/2020, Hugh Pyle via cctalk wrote:
> >I've cut Mylar tape with a Glowforge laser.  It cuts very nicely but the
> >alignment is a major hassle, plus you can only cut ~15" of tape which
> >doesn't go very far.  Not worth the effort.  If you were to build a custom
> >linear drive it might work.  But also very slow.
>
> Hmm.  You could have N fixed lasers at the spots of potential holes,
> and then a mechanism to move the whole assembly of them in the shape of a
> single hole, drawing them all at once.
>
> You could have one laser on that moved precisely along the hole row,
> and use the same sort of mechanical motion to draw a hole.
>
> How much laser do you need to cut paper, how much to cut mylar?
>
> Were there any paper tape devices that did not use the sprocket holes
> to move the tape?
>
> - John
>
>

DIY Paper Tape Punch - Mechanism diagram?

[Anders Nelson via cctalk]

Hi all,

I've had a paper tape reader for a while but never had a punch to make new
tapes, and the ones i've found are not only very large but also very
expensive. So I'm toying with the idea of making an open-source punch, but
I can't find any detailed diagrams of how the mechanism works.

I'm assuming (without any data to back it up) that there is a cam, an array
of spring-levered pins, and horizontal spacers controlled by solenoids that
bridge the gap between the cam and each punch pin when called for.

Does anyone have insight into how reliable/fast paper tape punches work?
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com

Dixie Canner CPT 8000?

[Anders Nelson via cctalk]

https://www.ebay.com/itm/143536589578

What in the world is this?

Re: Kennedy 9800 - Power-up tips?

[Anders Nelson via cctalk]

Hey this is all super useful info, thanks!

Any idea how to visually identify a tantalum cap? I suppose I could Google
it but maybe standards have changed between 1984 and 2020?

On Thu, Apr 23, 2020, 8:06 PM Jon Elson via cctalk 
wrote:

> On 04/23/2020 12:53 PM, Robert via cctalk wrote:
> > I'm under caffeinated and not really with it yet, having recently gone
> semi
> > nocturnal, so you'll want to double check this with someone who's
> actually
> > awake.
> >
> > That said, variacs aren't a universal panacea and can sometimes be
> harmful
> > rather than helpful.  My disorganized memory is offering TVs as an
> example,
> > but take that with a pinch of salt. I've only ever used them with tube
> > radios and amps, so have nothing further to offer,  save this caution.
> >
> Well, if the power supply is all linear, a Variac is
> probably fine to slowly ramp up the capacitors and
> let the dielectric reform.
>
> If it has switching power supplies, this can cause the
> supply to try to operate at severe undervoltage, and cause
> damage.  On the other hand, powering it up to 10 V or so on
> the AC input for a few minutes
> is unlikely to allow the switching stage to start up, but
> will reform the main input storage caps.
> It won't reform the low voltage caps in the rest of the
> unit, though.  You could apply low voltage
> (1-2 V for a minute or two) to each low voltage rail before
> fully powering on.  Especially if it
> has bunches of tantalum caps in the logic, that could
> prevent disaster.
>
> Jon
>

Re: Kennedy 9800 - Power-up tips?

[Anders Nelson via cctalk]

Thanks for all the input!

@Chuck: I assume you are talking about a 100W incandescent light bulb, I
like that idea for current-limiting. And I agree a SMPS should cut off the
switch if it detects a short; not sure what kind of supply is in there but
I'll take a look.

@Patrick: There's a stamp on the unit that seems to indicate it was made in
1984 but yeah the eBayer applied power normally before I got it.

Thanks!


On Thu, Apr 23, 2020, 2:21 PM Patrick Finnegan  wrote:

> On Thu, Apr 23, 2020 at 11:59 AM Anders Nelson via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> Cool, thanks for your take. I found some articles:
>>
>>-
>>
>> http://www.angelfire.com/electronic/funwithtubes/steps_to_first_power_on.html
>>- http://www.angelfire.com/electronic/funwithtubes/Restore_cap.html
>>
>> Given this unit doesn't have any tubes, I imagine the motor drivers/amps
>> in
>> this thing would simply go to zero output with shorted caps. The PSU might
>> blow the fuse and/or rectifier with a shorted bulk output cap. This unit
>> is
>> very difficult to remove from the rack it's in so I'm trying to avoid
>> preemptive repairs.
>>
>
> I'd personally say that since it hasn't been off for that long (less than
> 3 years) and since it sounds like you're not interested in taking it apart,
> I'd just plug it back in, and see how that goes.
>
> As a minimal step, I might disconnect the PSU from the rest of the drive,
> and plug it in like that for a moment, but it's probably best to not run it
> without a load for very long.
>
> Pat
>

Re: Kennedy 9800 - Power-up tips?

[Anders Nelson via cctalk]

Cool, thanks for your take. I found some articles:

   -
   http://www.angelfire.com/electronic/funwithtubes/steps_to_first_power_on.html
   - http://www.angelfire.com/electronic/funwithtubes/Restore_cap.html

Given this unit doesn't have any tubes, I imagine the motor drivers/amps in
this thing would simply go to zero output with shorted caps. The PSU might
blow the fuse and/or rectifier with a shorted bulk output cap. This unit is
very difficult to remove from the rack it's in so I'm trying to avoid
preemptive repairs.

I'm going to pick up a variac on Amazon when I finish up some other things:

https://www.amazon.com/dp/B076Y2XHRS/ref=twister_B07G5BHXYV

Happy to hear any constructive criticism.

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Thu, Apr 23, 2020 at 12:37 AM "Grif" w. keith griffith via cctalk <
cctalk@classiccmp.org> wrote:

>
> At least in radio repair of old equipment old electrolytic caps
> cause all sorts of issues. Most of the guys doing restoration do a total
> remove/replace on them.  In my opinion,,, I think that's a little
> extreme,,, but then having one fail after all the other work is done is
> also a PITA.
>
>
> On 4/20/20 11:15 AM, Anders Nelson via cctalk wrote:
> > Hi friends,
> >
> > Now that I have enough hobby time having quit my job two weeks before the
> > apocalypse, I'm interested in poking at my Kennedy 9800 tape controller
> > project.
> >
> > I bought the tape unit in Q3 2017 and the seller said they had powered it
> > up and nothing seemed awry. I have not powered it up and reading about
> old
> > electrolytic cap issues I'm curious if I should do anything beyond
> replace
> > any obviously leaking/ruptured capacitors.
> >
> > IIRC people have used a variac to gradually bring the power supply up to
> > operating voltage and somewhat refresh the capacitors - is this a thing?
> Is
> > this advisable?
> >
> > Any help is appreciated!
> > --
> > Anders Nelson
> >
> > www.erogear.com
>
>
>

Kennedy 9800 - Power-up tips?

[Anders Nelson via cctalk]

Hi friends,

Now that I have enough hobby time having quit my job two weeks before the
apocalypse, I'm interested in poking at my Kennedy 9800 tape controller
project.

I bought the tape unit in Q3 2017 and the seller said they had powered it
up and nothing seemed awry. I have not powered it up and reading about old
electrolytic cap issues I'm curious if I should do anything beyond replace
any obviously leaking/ruptured capacitors.

IIRC people have used a variac to gradually bring the power supply up to
operating voltage and somewhat refresh the capacitors - is this a thing? Is
this advisable?

Any help is appreciated!
--
Anders Nelson

www.erogear.com

Re: DEC QBUS Backplanes

[Anders Nelson via cctalk]

Smart!
--
Anders Nelson

www.erogear.com


On Fri, Apr 17, 2020 at 1:04 PM Bill Gunshannon via cctalk <
cctalk@classiccmp.org> wrote:

> On 4/17/20 12:57 PM, Anders Nelson via cctalk wrote:
> > Just curious - in all the backplane photos I've seen, it appears the
> > fragile wire wrapping is always exposed without a cover protecting it
> from
> > other components, fallen screws and wayward fingers in the computer
> cabinet.
> >
> > Was it ever standard practice to put a cover over these? I couldn't
> imagine
> > debugging or repairing a backplane...
>
> This particular backplane is soldered and has a rather heavy steel cover
> over it.
>
> bill
>
>
>

Re: DEC QBUS Backplanes

[Anders Nelson via cctalk]

Just curious - in all the backplane photos I've seen, it appears the
fragile wire wrapping is always exposed without a cover protecting it from
other components, fallen screws and wayward fingers in the computer cabinet.

Was it ever standard practice to put a cover over these? I couldn't imagine
debugging or repairing a backplane...

--
Anders Nelson

www.erogear.com


On Fri, Apr 17, 2020 at 12:52 PM Bill Gunshannon via cctalk <
cctalk@classiccmp.org> wrote:

>
>
> I have been sorting thru a bunch of stuff in an effort to
> clean the place up (Aren't we all doing that now with all
> this time on our hands?)  I found a backplane.  It says
> Digital on it but does not  have an H- number.  I also
> don;t find it listed in any  of the lists I can find on
> the web.
>
> It has 8 A-B slots and 4 C-D slots.  the Four C-D are on
> the bottom half of the backplane.  I am assuming it is
> 18 bit and the C-D were intended for things like the 2
> board RL controller.
>
> Anybody familiar with this and able to identify it?
> Anybody interested in it?  It should fit in a USPS
> Medium Flat Rate Box.
>
> bill
>

Re: Discord

[Anders Nelson via cctalk]

Medal of Honor is one of my all-time favorite games.

--
Anders Nelson


On Fri, Apr 10, 2020 at 4:09 PM jwest--- via cctalk 
wrote:

> Perma-invite
>
>
>
> https://discord.gg/CwhYHY2
>
>
>
> From: Derek Newland 
> Sent: Thursday, April 9, 2020 7:47 PM
> To: jw...@classiccmp.org; General Discussion: On-Topic and Off-Topic
> Posts 
> Subject: Re: Discord
>
>
>
> Hi J, it appears the invite has expired. Any chance to get a fresh one?
> Thanks!
>
>
>
> On Fri, Nov 15, 2019 at 12:55 PM jwest--- via cctalk <
> cctalk@classiccmp.org  > wrote:
>
> I believe I sent the invite to my game channel, NOT the new classiccmp
> server. please use this instead:
> https://discord.gg/gV6PKYW
>
> -Original Message-
> From: cctalk  cctalk-boun...@classiccmp.org> > On Behalf Of jwest--- via cctalk
> Sent: Friday, November 15, 2019 11:26 AM
> To: 'General Discussion: On-Topic and Off-Topic Posts' <
> cctalk@classiccmp.org  >
> Subject: Discord
>
> Greetings folks
>
>
>
> The past few years I’ve become fairly focused on a particular old
> 1999/2000 ww2 fps computer game. Of course playing it but I’m also on the
> development team for the game (EA has given up on it, but we still put out
> new releases, maps, patches, etc.). As a result of that, I pretty much live
> on Discord text/audio chat these days. If you send me an email I will
> eventually see it and may even respond heh. But if you send me anything on
> Discord I’m going to see it immediately. If any of you are on discord, I am
> “Todesengel#9624”. Feel free to add me as a friend and that way you can get
> me usually immediately. I am not leaving the hobby, nor am I saying not to
> email me at the usual address. But a lot of you do talk to me
> semi-frequently and I’m just saying discord will get to me far quicker.
>
>
>
> In addition, mostly as an exercise to see how to do it, I set up a
> ClassicCMP discord server. That Discord server is NOT meant to replace this
> list, nor should it be taken to signal any less commitment on my part to
> keeping this list running. They are fundamentally different things; Discord
> is great for real time text chat back and forth. There are also audio and
> video channels if people want to use that to talk verbally or via video. To
> get on that server, here is a semi-permanent invite:
> https://discord.gg/U8Skw5g  Joining the server gets you to all the other
> folks who may join the classiccmp discord, not just me. Of course, that
> could be zero 😊 Like I said, I just did it as an exercise, and discord is
> how some of my family and friends stay in touch. But it is there if peeps
> want to use it.
>
>
>
> I’d rather not turn this into a long debate of whether discord is good or
> bad or anything like that. I’m just saying it’s there, and it’s quicker to
> get ahold of me that way at times.
>
>
>
> Best,
>
>
>
> J
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> --
>
> Derek Newland | (828) 234-4731 |  
> derek.newl...@gmail.com
>
>

eBay: 2x IBM 5114 and 5103

[Anders Nelson via cctalk]

I don't have enough space, but these look neat!

https://www.ebay.com/itm/Vintage-IBM-5114-disk-drive-5103-printer-for-5110-computer-two-of-each-/333407338900

--
Anders

Re: Another old phart trying to clean out the house

[Anders Nelson via cctalk]

Interested in pictures of piles!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Mon, Jan 13, 2020 at 2:04 PM Ethan Dicks via cctalk <
cctalk@classiccmp.org> wrote:

> On Mon, Jan 13, 2020 at 11:46 AM Jack Rubin via cctalk
>  wrote:
> > If there is anyone in the greater Chicago area (or anywhere else) who'd
> like to drive over and take away anything from a carton to a carload of old
> stuff, from docs to chips, please let me know. No inventory list, no
> shipping - just a walk-through and carry out.
> >
> > In another two weeks (end of January), I'll be trashing most of it.
>
> Unfortunately, I am 400 miles away and not going to be in the area
> until mid-February.
>
> -ethan
>

Re: Sperry SP-425-08 Display - Datasheet?

[Anders Nelson via cctalk]

Wow, thanks for all the info! I'd love to see examples of driving circuitry
if it's not too much trouble. I've made PCBs and such before so aside from
potentially jolting myself I'm up to the challenge.

Anything I produce (code, schematics/PCBs) will be posted to my blog as
open-source material.

Thanks again,

Anders

On Wed, Jan 1, 2020, 8:34 PM Brent Hilpert via cctalk 
wrote:

> On 2020-Jan-01, at 2:42 PM, Anders Nelson via cctalk wrote:
> > I snagged one of these Nixie-like displays (from a calculator I assume)
> and
> > I'd like to light it up. Does anyone know where I might find the
> datasheet
> > for it? Google hasn't turned up anything.
> >
> > https://www.ebay.com/itm/264110638970
> >
> > Any help is appreciated!
>
>
> 7-segment multiplexed multi-digit gas-discharge display.
>
> Those Sperry types weren't very prevalent, I'm not surprised you haven't
> found a datasheet.
>
> I'm being a little presumptuous in specifying gas-disharge, it certainly
> appears to be, but the ebay pics are a little small.
>
> There was another series of GD displays from Sperry, and another from
> Beckman, which were more prevalent.
>
> Assuming it is GD:
>
> I have an example of one that appears to be of similar construction to
> yours in this calculator:
> http://madrona.ca/e/eec/calcs/SanyoICC83.html
> Given yours says made in Japan, I wonder if they be from the same OEM.
> I can send the schematic if you wish, for an example of drive circuitry.
> It needs a little reformatting and conversion to pdf first, so let me know
> if interested.
>
> I have other calculators and schematics using the Beckman displays
> (7-segment, multiplexed, multi-digit, gas-discharge).
> They could also be comparitive examples for drive circuitry.
>
> Multiplexed gas discharge displays could be a little finicky to drive, to
> keep down anomylous ghosting and partial ignition.
>
> In the absence of a datasheet, your first task would be to distinguish the
> digit anodes from the segment cathodes.
> You might be able to do it visually by looking at the internal
> construction.
> Otherwise experimentation with two probes connected to a 150-200V power
> supply with a series limiting resistor of 200K or maybe even higher to
> start with.
>
>

Sperry SP-425-08 Display - Datasheet?

[Anders Nelson via cctalk]

Hi all,

I snagged one of these Nixie-like displays (from a calculator I assume) and
I'd like to light it up. Does anyone know where I might find the datasheet
for it? Google hasn't turned up anything.

https://www.ebay.com/itm/264110638970

Any help is appreciated!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com

Re: FS: System/36 Kansas City

[Anders Nelson via cctalk]

A saint's work is never done! I wouldn't know what to do with it but glad
it's not being scrapped.

On Fri, Dec 13, 2019, 1:15 PM jim stephens via cctalk 
wrote:

> I'm in contact with the owner, arranging to pick it up.  If anyone on
> the list is interested, let me know.
>
> This is a "must go asap" issue for the system involved. I'm not going to
> ask anything if anyone needs the system, just let me know. I've got a
> warehouse in KC near this location where we're going to move it to.
>
> I'll update if we get it tomorrow or the next day.
>
> thanks
> Jim
>
> On 12/13/2019 9:26 AM, Dave Wade via cctalk wrote:
> > In case any one is interested..
> >
> >
> >
> >
> https://www.facebook.com/groups/retrocomputers/permalink/3042809669082227/
> >
> >
> >
> > Dave Wade
> >
> > G4UGM & EA7KAE
> >
> >
> >
> >
>
>

Re: Compaq Floppy/Printer board?

[Anders Nelson via cctalk]

Also what appears to be a quad serial board:

https://photos.app.goo.gl/21EvJcc7KwwDuS4t9

=]

On Fri, Nov 29, 2019, 3:25 PM Anders Nelson 
wrote:

> Hi all, I found this while throwing away e-waste at my old place:
>
> https://photos.app.goo.gl/R8xUxYijf1AYHNB38
>
> Is it of any use to anyone? Need to know by Sunday.
>
> Thanks!
>

Compaq Floppy/Printer board?

[Anders Nelson via cctalk]

Hi all, I found this while throwing away e-waste at my old place:

https://photos.app.goo.gl/R8xUxYijf1AYHNB38

Is it of any use to anyone? Need to know by Sunday.

Thanks!

Re: Discord

[Anders Nelson via cctalk]

FWIW Medal of Honor is one of my all-time favorite games, and definitely my
favorite WW2 game. Nice job.

On Sat, Nov 16, 2019, 2:01 AM Steve Malikoff via cctalk <
cctalk@classiccmp.org> wrote:

> J said
> Discord is great for real time text chat back and forth. There are also
> audio and video channels if people want to use that to talk verbally or via
> video. >
> > I’d rather not turn this into a long debate of whether discord is good
> or bad or anything like that. I’m just saying it’s there, and it’s quicker
> to get ahold of me that way at times.
>
> I'm not sure if the feature of more real-time conversation on Discord
> would be of much if any benefit to me.
>
> Since I am at +10 GMT most of the conversation on cctalk already happens
> during the small hours here, so
> in the morning I have the bulk of the day's worth of US/Europe timezoned
> postings to browse through with
> questions posed and already answered in numerous followups (and 'For Sale'
> items well and truly snapped up :)
>
> If I was on after midnight local time, I guess it might be useful and I
> should take a look at it, but so
> far I'm pretty happy with cctalk as it is now.
>
> Steve.
>
>
>

Re: Repurposing cable for IBM Model M Keyboard

[Anders Nelson via cctalk]

Maybe buy a more modern cable and hack that instead?:

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F283062451183

On Wed, Nov 6, 2019, 9:57 AM Liam Proven via cctalk 
wrote:

> On Wed, 6 Nov 2019 at 15:31, Rob Jarratt via cctalk
>  wrote:
> >
> > However, I now have a pang of conscience about hacking around with a
> > perfectly good cable, particularly if they are uncommon. How common are
> > these cables?
>
> I don't know for sure but I've certainly seen people looking for them.
> Not super-common I'd say, and I wouldn't do it myself.
>
> --
> Liam Proven - Profile: https://about.me/liamproven
> Email: lpro...@cix.co.uk - Google Mail/Hangouts/Plus: lpro...@gmail.com
> Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven
> UK: +44 7939-087884 - ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
>

Re: ADM-3A question

[Anders Nelson via cctalk]

"and that's why he's cranky. (Well, more so than he usually is :-)"

A wealth of vintage cmp information, but good heavens he is cranky.

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Wed, Aug 14, 2019 at 2:01 PM Noel Chiappa via cctalk <
cctalk@classiccmp.org> wrote:

> >> Al Kossow via cctalk writes:
>
> >> Buried in a filing cabinet in the basement with a sign that says
> >> "Beware of Leopard".
>
> Good one!
>
> > From: Seth J. Morabito
>
> > I'm going to respectfully disagree .. the proliferation of modern
> > JavaScript frameworks that are designed to build single-page apps,
> and
> > make the web virtually impossible to scrape or mirror in an efficient
> > and simple way. ... every single page is statically generated at
> > publishing time and absolutely nothing is dynamic.
>
> It's not clear that it's the dynamic nature of the content he's unhappy
> with;
> it might just be that having stuff scattered across a zillion personal
> pages
> (be they blogs, or whatever) is going to make it hard to find the useful
> one
> when needed, and that's why he's cranky. (Well, more so than he usually
> is :-)
>
> If it's got something oddball term in the text, a Web indexer might be able
> to find it, but what if your search term turns up 17,239 matches? Finding
> the
> useful needle in the hackstack of crap on the current Web is a tall order -
> so tall, that I suspect a lot of people don't even try, just shoot off an
> email to CCTalk in the hopes that someone here will enlighten them.
>
> I've seen a number of instances recently where people's questions were
> answered on the CHWiki, but apparently they couldn't find it. So they
> wound up asking here...
>
> Noel
>

Re: ADM-3A question

[Anders Nelson via cctalk]

I hope this thread will be written to a blog post? Lots of good info here!

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Wed, Aug 14, 2019 at 10:25 AM Charles via cctalk 
wrote:

> Thanks. I believe you are right also :)
> The expensive ceramic packages have hermetic seals, not so the plastic
> (epoxy) packages used in commercial grade parts.
>
> There are some kind of failures that can be fixed by baking - but I don't
> know if this is one of them (if the bond wire is soldered to the die it
> might work). If it detached from the weld at the lead frame, no go. Anyway
> there are over 100 chips on the ADM-3A board and I would be more worried
> about damaging the others with heat.
> I just paid 71 cents for another LS193 ;)
>
> Charles
> WB3JOK/0
>
> -Original Message-
> From: Dave Wade
> Sent: Wednesday, August 14, 2019 5:02 AM
> To: 'Charles' ; 'General Discussion: On-Topic and Off-Topic Posts'
> Subject: RE: ADM-3A question
>
> Charles,
>
> I believe that TTL chips suffer from failure or detachment of the bonding
> wire that runs from the die to the interconnect pin, which would result in
> a
> floating pin as described.]
> Not sure if environmental storage affects this as chips should be sealed...
>
> I have also recently seen it suggested that heating the chip up in an oven
> could affect a temporary repair (sorry I can't find the reference now).
>
> Dave
> G4UGM
>
> > -Original Message-
> > From: cctalk  On Behalf Of Charles via
> cctalk
> > Sent: 14 August 2019 00:20
> > To: cctalk digest 
> > Subject: Re: ADM-3A question
> >
> > After hanging vertically for 36 hrs in a hot upstairs room, more goop
> seeped
> > out from under the keyboard. It now works again. Whew.
> >
> > While running on the bench for burn-in testing, a cursor problem suddenly
> > appeared... it would only move every other keystroke. With the technical
> > description and schematic at hand, it wasn't hard to track down a 74LS193
> > up/down counter with a blown (floating) LSB output. Confirmed by manually
> > toggling that bit and the cursor would move back and forth one position.
> > Meanwhile I removed the bad chip and put in a DIP socket. Naturally my
> TTL
> > collection didn't have an 'LS193 so I'm waiting on that. So I have a 24
> line, 1
> > column terminal :)
> >
> > The monitor was occasionally intermittent (no display at all, no HV, +15
> and
> > drive signals OK). It seemed to change with movement of the wiring
> harness
> > from the main board to the monitor, too. I reseated the edge connector on
> its
> > PCB and it seemed to be fixed - but then the VERTICAL deflection
> collapsed
> and
> > tweaking the height adjustment caused increasing loss. The 100 ohm pot to
> the
> > base of the vertical output transistor had picked that moment to go open.
> > Changed that out and readjusted everything - so far so good after another
> hour
> > of run time.
> >
> > This ADM-3A could have been unpowered (and in a storage area without
> > climate
> > control) for a very long time. I wonder if that contributed to the
> failures I'm
> > seeing... hope there aren't any more until I get to use it for a while on
> my PDP-
> > 8/A (or 11/23+).
> >
> >
> > ---
> > This email has been checked for viruses by Avast antivirus software.
> > https://www.avast.com/antivirus
>
>

Re: RF08 light panel

[Anders Nelson via cctalk]

$113.50 seems pretty cheap to me, that's like four cocktails in Manhattan.

Hope someone on this list got it!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Mon, Jul 15, 2019 at 1:57 AM Ethan Dicks via cctalk <
cctalk@classiccmp.org> wrote:

> On Mon, Jul 8, 2019 at 6:28 PM Al Kossow via cctalk
>  wrote:
> > bet this won't go cheap
> >
> > https://www.ebay.com/itm/372706567865
>
> Did anyone here get it?  I did not bid because I have zero parts of an
> RF08 (and if I ever make a modern RF08 emulator, I might as well make
> one of these to match).
>
> -ethan
>

PM2390 Clock and Sector writer

[Anders Nelson via cctalk]

Found on eBay: https://www.ebay.com/itm/223506026636

I suppose Kyroflux and other open-source hardware/software combos can do
the same thing?
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com

Re: Service for converting CD-ROMs into ISO files?

[Anders Nelson via cctalk]

If you want to do it yourself,

Mac: https://www.provideocoalition.com/howto_create_dvd_iso_from_files_mac/
Windows: http://wincdemu.sysprogs.org/tutorials/create/

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Sat, May 4, 2019 at 12:53 AM J. Peterson via cctech <
cct...@classiccmp.org> wrote:

> Hi,
>
> I have a stack of a few dozen CD-ROM disks with various files (old
> software, backup files, photos). I'm willing to pay a reasonable rate
> to have somebody read each of these in, convert them to .ISO files or
> some other reasonable format, and either make them downloadable or
> put them on a thumb drive.
>
> Does anybody know of such a service? I can find lots of services for
> converting  audio CD's into MP3 files, but nothing that specifically
> handles data CD-ROMs.
>
> Any leads most appreciated. Please reply directly, as I don't often
> check this list.
>
> Thanks,
> jp
>
>
>

Re: I need some education (PDP)

[Anders Nelson via cctalk]

Please send along that list when you get it.

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Fri, May 3, 2019 at 4:05 PM Electronics Plus via cctalk <
cctalk@classiccmp.org> wrote:

> So I called my buddy of 20+ years.
>
> Got old PDP junk left?
>
> Like what kinda junk?
>
> PDP 8 or 11?
>
> Hmm, got PDP 8 boards and BA11 boxes. PDP11 makes no sense, it is a series,
> 11/70 or what?
>
>
>
> I know NOTHING about this stuff. I told him slide in boxes with flippy
> switches. He laughed and said he will send me over a list of all the OLD
> DEC
> stuff left in the warehouse. Shipping will be from Calif. Pickup avail, or
> shipping, for rack stuff.
>
>
>
> Cindy Croxton
>
> Electronics Plus
>
> 1613 Water Street
>
> Kerrville, TX 78028
>
> 830-370-3239 cell
>
> sa...@elecplus.com
>
>
>
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
>

Re: IBM 6360 - interface help?

[Anders Nelson via cctalk]

CCing the list back in, and still looking for someone in the NY area with a
Displaywriter (with disk drive) that could help me take some logic traces -



Quoth Nigel:

just in case you missed it your reply only went to me.

On Mon, Apr 22, 2019 at 1:45 PM Anders Nelson 
wrote:
> Nigel - Wow, very cool! I assume you dumped a ROM feeding an 8048 inside
the 6360 drive housing?

Someone dumped the original ROM, it is in the github repo too.

> FWIW, I also found a Displaywriter withOUT keyboard or disk drive:
https://www.ebay.com/itm/Vintage-1984-IBM-6580-Display-Station-Word-Processor-and-Monitor/303132621814

If you want a 6580 keyboard you either have to get lucky or outbid the
mech-heads...be prepared to bid a lot though. Estate sales are the
thing to haunt to get one intact.



Thanks Nigel, more below!

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Sun, Apr 21, 2019 at 11:45 PM Anders Nelson 
wrote:

> Nigel - Wow, very cool! I assume you dumped a ROM feeding an 8048 inside
> the 6360 drive housing?
>
> I agree a logic dump would be invaluable so if I can get in front of a DW
> I'll capture and share all I find on my blog (and wherever else).
>
> Al - I found a USB conversion kit for this keyboard and it's all
> open-source, so by reversing the key-matrix decode step in the kit's MCU
> firmware we might be able to feed the original keyboard controller with
> keystrokes from, say, another USB keyboard. A very roundabout hack but it
> seems these keyboards are rare. Here are the conversion kit sources:
>
> Forum: https://geekhack.org/index.php?topic=58138.0
> Direct: http://downloads.cornall.co/ibm-capsense-usb/
>
> Any chance someone knows the original keyboard controller pinout and
> protocol?
>
> FWIW, I also found a Displaywriter withOUT keyboard or disk drive:
> https://www.ebay.com/itm/Vintage-1984-IBM-6580-Display-Station-Word-Processor-and-Monitor/303132621814
>
> =]
> --
> Anders Nelson
>
> +1 (517) 775-6129
>
> www.erogear.com
>
>
> On Sun, Apr 21, 2019 at 11:12 PM Nigel Williams <
> n...@retrocomputingtasmania.com> wrote:
>
>> Hi Anders,
>>
>> good luck with your exploration of the 6360.
>>
>> Back in Jan-2017, I assisted Sergey who did the MAME implementation of
>> the Displaywriter, as Al Kossow mentioned in an earlier email the code
>> is here:
>>
>>
>> https://github.com/mamedev/mame/blob/97b67170277437131adf6ed4d60139c172529e4f/src/mame/machine/ibm6580_fdc.cpp
>>
>> During this process I started disassembling the 6360, attached is a
>> file that I developed with comments. It is incomplete but might help
>> understand the protocol.
>>
>> One thing to keep in mind is that the Displaywriter is made up of
>> (almost) standalone subsystems, so the floppy drive unit has its own
>> 8048 microprocessor and accepts high-level commands from the system
>> unit.
>>
>> Sergey and I were chatting about returning to work on the MAME
>> Displaywriter implementation at some point. We really need a
>> logic-analyser dump of the startup since it is very convoluted (it has
>> a large section of code attempting to check that all the hardware is
>> working so it is doing all manner of tricks to check things).
>>
>> cheers,
>> nigel.
>> www.retroComputingTasmania.com
>>
>>
>> On Mon, Apr 1, 2019 at 6:42 AM Anders Nelson via cctalk
>>  wrote:
>> > Can anyone help with the protocol?
>>
>

Re: Programming on metal cylinders?

[Anders Nelson via cctalk]

This one?: https://youtu.be/YyxGIbtMS9E

Probably not.
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Mon, Apr 22, 2019 at 1:09 PM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:

> On 4/21/19 7:11 AM, John Foust via cctalk wrote:
> >
> > I was assisting an older client the other day, a former Yale prof,
> > and he's been programming since the late 1950s.
> >
> > He knew people who worked at Bletchley Park.  He also mentioned he
> > knew people who had manually scribed their programs on some sort of metal
> > cylinder.  Which computer system was that?
> >
> > Part of what he'd like me to help with is a circa 2001 Compaq / DIGITAL
> > version of a FORTRAN programming environment.  He had not yet found
> > the installation media so we could try to get it running on Windows 10.
> > I wonder if it will...
>
> Could this be something that uses the same technology as a drum program
> card on a keypunch?
>
> --Chuck
>
>

Re: IBM 6360 - interface help?

[Anders Nelson via cctalk]

Looks like this guy has the Displaywriter keyboard protocol on his to-do
list:

http://www.kbdbabel.org/
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Sun, Apr 21, 2019 at 10:15 PM Anders Nelson 
wrote:

> Cool, do you happen to have schematics for the keyboard or a description
> of the signaling? I could help make a hardware convertor that takes in a
> USB keyboard and spit out DW keystrokes...
>
> A POST logic trace would be helpful I'm sure - where are you located? We
> can take this off-list if you prefer.
>
> =]
> --
> Anders Nelson
>
> +1 (517) 775-6129
>
> www.erogear.com
>
>
> On Sun, Apr 21, 2019 at 12:24 PM Al Kossow via cctalk <
> cctalk@classiccmp.org> wrote:
>
>>
>>
>> On 4/20/19 3:47 PM, Anders Nelson via cctalk wrote:
>> > I haven't found any more info on the signaling that goes
>> > over the DB37 data cable, and I would like to use my portable logic
>> > analyzer to sniff out some basics:
>>
>> I could help you, I have several DWs and I want to document the hardware,
>> but thanks to kb vultures I've not been able to find a complete keyboard.
>> I have the PCB and cable but none of the mechanical parts.
>>
>> I guess I could try hooking that up to try to get past POST.
>>
>>

Re: IBM 6360 - interface help?

[Anders Nelson via cctalk]

Cool, do you happen to have schematics for the keyboard or a description of
the signaling? I could help make a hardware convertor that takes in a USB
keyboard and spit out DW keystrokes...

A POST logic trace would be helpful I'm sure - where are you located? We
can take this off-list if you prefer.

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Sun, Apr 21, 2019 at 12:24 PM Al Kossow via cctalk 
wrote:

>
>
> On 4/20/19 3:47 PM, Anders Nelson via cctalk wrote:
> > I haven't found any more info on the signaling that goes
> > over the DB37 data cable, and I would like to use my portable logic
> > analyzer to sniff out some basics:
>
> I could help you, I have several DWs and I want to document the hardware,
> but thanks to kb vultures I've not been able to find a complete keyboard.
> I have the PCB and cable but none of the mechanical parts.
>
> I guess I could try hooking that up to try to get past POST.
>
>

Re: IBM 6360 - interface help?

[Anders Nelson via cctalk]

Hi again,

Is there anyone within ~100 miles of the NYC area with a working IBM
Displaywriter? I haven't found any more info on the signaling that goes
over the DB37 data cable, and I would like to use my portable logic
analyzer to sniff out some basics:

   - Boot
   - File Read
   - File Write

Any leads would be appreciated!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Sun, Mar 31, 2019 at 6:03 PM Anders Nelson 
wrote:

> Hey Al,
>
> I haven't looked at the MAME stuff but if it uses an NEC 765 then it
> probably won't be the same. The signal list is quite a bit different, e.g.
> only 5 non-contiguous address bits are used. Real weird.
>
> I'll take a look all the same.
>
> =]
>
> On Sun, Mar 31, 2019, 4:30 PM Al Kossow via cctalk  wrote:
>
>>
>>
>> On 3/31/19 12:42 PM, Anders Nelson via cctalk wrote:
>>
>> > I've read through the service manuals and other docs on Bitsavers but I
>> > can't seem to find a deeper explanation on the protocol that runs over
>> the
>> > DB-37 cable.
>>
>> Have you looked at the displaywriter MAME driver?
>>
>> The floppy uses an NEC 765 disk controller
>>
>>
>>
>>

Re: Plane of core memory

[Anders Nelson via cctalk]

I believe I read they weaved the planes this way to minimize crosstalk, EMI
or heat.

=]

On Thu, Apr 18, 2019, 1:13 PM Paul Koning via cctalk 
wrote:

>
>
> > On Apr 18, 2019, at 11:47 AM, Jon Elson via cctalk <
> cctalk@classiccmp.org> wrote:
> >
> > On 04/18/2019 04:49 AM, Brent Hilpert via cctalk wrote:
> >> It's a 4-wire 3D planar array. By topology and construction I would
> guess it date it from the 60s.
> > Make that EARLY '60s.  As soon as somebody figured out that you could
> combine the sense and inhibit wires, everybody immediately went to 3-wire
> planes.
> >
> > Jon
>
> Is that true even for the highest speed designs?
>
> CDC 6000 series memory is unusual in that it has 5 wires per core.
> Instead of the classic X, Y, Inhibit, Sense it has two inhibit wires,
> routed in the X and Y direction.  There are four X and four Y inhibit
> wires, each of which run through 1/4th of the cores, so a given inhibit
> pair acts on 1/16th of the cores.
>
> The documentation doesn't spell out why this is done.  My guess is that it
> makes the various driven wires more alike in how many cores they pass
> through.  X and Y, in the 12 bit stack, pass through 64 * 12 cores.  Each
> inhibit wire passes through 64 * 16 cores, i.e., nearly the same number.
> And the driver circuits for all these wires are the same.
>
> A regular full-plane inhibit wire would pass through 4k cores, meaning the
> inductance is far higher than that of the X and Y wires.  So either the
> drive circuit would require a lot more power, or it would be significantly
> slower than the X/Y drive.
>
> As for separate sense, split inhibit obviously requires that, but even
> with conventional inhibit, keeping sense separate avoids the overhead of
> switching the signal path between two very different bits of circuitry.
>
> Compared to many other core memory designs of that same era, the 6000
> memory is quite fast, with access times of a few hundred nanoseconds and
> full cycle (read plus restore) in one microsecond.  Actually, comfortably
> under 1 microsecond, allowing for magic like read and update in one cycle
> (for the exchange instruction in the CPU) or read and write new data in one
> cycle via the ALU data path (in the PPUs).  I suspect the unusual core
> plane design was a factor in making this speed possible.
>
> paul
>
>

Re: PDP-8: count number of set bits in a word

[Anders Nelson via cctalk]

I suppose you could test each nybble for zero, then equate a 16-element LUT
on nybbles not zero?

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Fri, Apr 5, 2019 at 11:59 AM Kyle Owen via cctalk 
wrote:

> Just wondering if anyone has come up with a fast way to count the number of
> 1s in a word on a PDP-8. The obvious way is looping 12 times, rotating the
> word through the link or sign bit, incrementing a count based on the value
> of the link or sign.
>
> With a small lookup table, you can reduce the total number of loops by
> counting multiple groups of bits at a time, but this of course comes with
> the cost of using more memory. Any other suggestions?
>
> Much appreciated,
>
> Kyle
>

Re: Yes there is a PDP 10 front panel and Kenbak on Ebay

[Anders Nelson via cctalk]

Nope!

On Wed, Apr 3, 2019, 3:58 PM ED SHARPE via cctalk 
> any  relation  to  marlys nelson  at  river falls?
> Ed#In a message dated 4/3/2019 12:40:06 PM US Mountain Standard Time,
> cctalk@classiccmp.org writes:
> I mean that semi-sarcastically as this list probably knows better already.
>
> =]
> --
> Anders Nelson
>
> +1 (517) 775-6129
>
> www.erogear.com
>
>
> On Wed, Apr 3, 2019 at 3:37 PM Anders Nelson 
> wrote:
>
> > My god people, stop bidding! There are 6 days left.
> > --
> > Anders Nelson
> >
> > +1 (517) 775-6129
> >
> > www.erogear.com
> >
> >
> > On Wed, Apr 3, 2019 at 2:51 PM Bill Degnan via cctalk <
> > cctalk@classiccmp.org> wrote:
> >
> >> Yes there is a PDP 10 front panel and  Kenbak on Ebay
> >>
> >> and no, a "best offer" of $250 for the front panel will not be accepted.
> >> :-)
> >>
> >> Bill
> >>
> >
>

Re: Yes there is a PDP 10 front panel and Kenbak on Ebay

[Anders Nelson via cctalk]

I mean that semi-sarcastically as this list probably knows better already.

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Wed, Apr 3, 2019 at 3:37 PM Anders Nelson 
wrote:

> My god people, stop bidding! There are 6 days left.
> --
> Anders Nelson
>
> +1 (517) 775-6129
>
> www.erogear.com
>
>
> On Wed, Apr 3, 2019 at 2:51 PM Bill Degnan via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> Yes there is a PDP 10 front panel and  Kenbak on Ebay
>>
>> and no, a "best offer" of $250 for the front panel will not be accepted.
>> :-)
>>
>> Bill
>>
>

Re: Yes there is a PDP 10 front panel and Kenbak on Ebay

[Anders Nelson via cctalk]

My god people, stop bidding! There are 6 days left.
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Wed, Apr 3, 2019 at 2:51 PM Bill Degnan via cctalk 
wrote:

> Yes there is a PDP 10 front panel and  Kenbak on Ebay
>
> and no, a "best offer" of $250 for the front panel will not be accepted.
> :-)
>
> Bill
>

Re: Burroughs BU4400 tape drive. What is it?

[Anders Nelson via cctalk]

Hey Tony,

Here is a 10-pack of 9-track tapes for $10USD:
https://www.ebay.com/itm/BASF-9-Track-Mag-Tapes-Brand-New-Case-of-10/112152910883

Shipping to NZ will probably be $100... I bought one of these boxes and
could send you a single tape if you need it, but I imagine there's someone
with a tape they don't need closer to you.

Let me know!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Tue, Apr 2, 2019 at 8:41 PM Chuck Guzis via cctalk 
wrote:

> On 4/2/19 3:04 PM, mike--- via cctalk wrote:
>
> > Looks like you're right! I'm pretty sure it's a cleaner. Everything on
> > it seems to work well, once I figured out how it was intended to work.
> > Just had fool the tape optical sensor (BOT/EOT?) with a piece of paper
> > and it started up fine. It only seems to want to go 'slow' in reverse,
> > but that may be something to do with the lack of tape. I like the tape
> > counter a lot. It shows error codes when they occur, and is a dot matrix
> > style LED display (perhaps not true dot matrix, just something nicer
> > looking than a 7-segment display).
>
> If you're going to use this thing, do check the carbide (sometimes
> ceramic) cleaning blade.  You want the edge to be sharp and smooth; if
> it's nicked or chipped, it will end up doing more harm than good.
>
> I suspect that a carbide insert for machine tools might be cobbled up as
> a replacement, if required.
>
> --Chuck
>
>

Re: IBM 6360 - interface help?

[Anders Nelson via cctalk]

Hey Al,

I haven't looked at the MAME stuff but if it uses an NEC 765 then it
probably won't be the same. The signal list is quite a bit different, e.g.
only 5 non-contiguous address bits are used. Real weird.

I'll take a look all the same.

=]

On Sun, Mar 31, 2019, 4:30 PM Al Kossow via cctalk 
>
> On 3/31/19 12:42 PM, Anders Nelson via cctalk wrote:
>
> > I've read through the service manuals and other docs on Bitsavers but I
> > can't seem to find a deeper explanation on the protocol that runs over
> the
> > DB-37 cable.
>
> Have you looked at the displaywriter MAME driver?
>
> The floppy uses an NEC 765 disk controller
>
>
>
>

Re: IBM 6360 - interface help?

[Anders Nelson via cctalk]

Also I should note that I live in NYC, so if anyone around these parts has
a working Displaywriter I am willing to drive a bit and bring my portable
logic analyzer with me to capture traffic along the data connector.

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Sun, Mar 31, 2019 at 3:42 PM Anders Nelson 
wrote:

> Hey all,
>
> I'm writing a blog post about this IBM 6360 disk controller I want to
> build:
>
> https://www.andersknelson.com/blog/?p=601
>
> I've read through the service manuals and other docs on Bitsavers but I
> can't seem to find a deeper explanation on the protocol that runs over the
> DB-37 cable.
>
> I suppose I could bypass the controller inside the drive cabinet and
> directly control the drives but I bet it'll be easier/better to use as much
> of the electronics as possible.
>
> Can anyone help with the protocol?
>
> Thanks!
> --
> Anders Nelson
>
> +1 (517) 775-6129
>
> www.erogear.com
>

IBM 6360 - interface help?

[Anders Nelson via cctalk]

Hey all,

I'm writing a blog post about this IBM 6360 disk controller I want to build:

https://www.andersknelson.com/blog/?p=601

I've read through the service manuals and other docs on Bitsavers but I
can't seem to find a deeper explanation on the protocol that runs over the
DB-37 cable.

I suppose I could bypass the controller inside the drive cabinet and
directly control the drives but I bet it'll be easier/better to use as much
of the electronics as possible.

Can anyone help with the protocol?

Thanks!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com

eBay: RCA CDP1802

[Anders Nelson via cctalk]

IIRC someone on this list was asking for an 1802 some time ago...

https://www.ebay.com/itm/CDP1802-CPU/132727125007

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com

Re: IBM 6360 - Filesystem(ish) info?

[Anders Nelson via cctalk]

Ah, cool thanks!

I'm interested in storing arbitrary files in the manner close to the
original as possible. Sounds like the extent list and allocation map would
be useful for this; not so much the document content format.
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Tue, Feb 19, 2019 at 2:44 PM Chuck Guzis  wrote:

> On 2/19/19 11:12 AM, Anders Nelson wrote:
> > Hi again,
> >
> > Is there a description of the DW filesystem somewhere I can look at?
>
> Hi Anders,
>
> Not that I'm aware of, unless Al has some document squirreled away that
> we don't know about.
>
> What I know is from a lot of examining DW floppies and trying to
> reverse-engineer it--and what little I could find on the web.
>
> The DW filesystem is basically a linked-list sort of structure.  There's
> a volume header block that contains an extent list and allocation map,
> from which documents are treed from.  Each document, in turn, links to
> other entries that describe various properties of each document.  For
> example, the dates of the document, its name, the list of positions of
> lines within the document, the document text, the formatting information
> for the text, and so on.   It's pretty complicated.
>
> One aside is that even though the DW is an 8086 system, numeric
> quantities are big-endian.
>
> --Chuck
>
>

Re: IBM 6360 - Filesystem(ish) info?

[Anders Nelson via cctalk]

Hi again,

Is there a description of the DW filesystem somewhere I can look at?

On Tue, Feb 19, 2019, 2:11 PM Anders Nelson  Ali - you bet I will! =P
>
> Chuck - thanks for the notes. I have no idea what it actually came from
> but I imagine it did come with a Display writer system. No problem with the
> format in which the data is stored, I can always present a more reasonable
> storage interface to the user via FTP or something. EBCDIC conversion or
> simply writing arbitrary bits is fine with me.
>
>
> On Tue, Feb 19, 2019, 1:54 PM Chuck Guzis via cctalk <
> cctalk@classiccmp.org wrote:
>
>> On 2/19/19 8:48 AM, Anders Nelson via cctalk wrote:
>> > Hi friends,
>> >
>> > Now that I have my glorious disk toaster (2D model I think, says "2D" on
>> > the drive levers), I want to build a controller for it. I found pinouts
>> and
>> > some description of the media organization here:
>> >
>> >
>> http://bitsavers.trailing-edge.com/pdf/ibm/6580_Displaywriter/S241-6248-3_Displaywriter_6360_6580_Product_Support_Manual_Feb1983.pdf
>> >
>> > I'd like to actually store data to these disks in the same manner the
>> > original systems did, and I'm proficient in hardware/firmware. Has
>> anyone
>> > made a controller for this already? How about emulating the filesystem?
>> >
>> > Any help is appreciated, and I'd open-source whatever I make (PCBs,
>> > firmware, etc.).
>>
>> Are you talking about the disk unit for the Displaywriter (6580)?
>>
>> Those don't use what you'd call a general-purpose filesystem in their
>> native mode (although there was a version of CP/M 86).  The DW
>> filesystem is very specific to that word-processing application and
>> probably not useful for general-purpose applications.  And, of course,
>> the character code used is EBCDIC.
>>
>> --Chuck
>>
>>
>>

Re: IBM 6360 - Filesystem(ish) info?

[Anders Nelson via cctalk]

Ali - you bet I will! =P

Chuck - thanks for the notes. I have no idea what it actually came from but
I imagine it did come with a Display writer system. No problem with the
format in which the data is stored, I can always present a more reasonable
storage interface to the user via FTP or something. EBCDIC conversion or
simply writing arbitrary bits is fine with me.


On Tue, Feb 19, 2019, 1:54 PM Chuck Guzis via cctalk  On 2/19/19 8:48 AM, Anders Nelson via cctalk wrote:
> > Hi friends,
> >
> > Now that I have my glorious disk toaster (2D model I think, says "2D" on
> > the drive levers), I want to build a controller for it. I found pinouts
> and
> > some description of the media organization here:
> >
> >
> http://bitsavers.trailing-edge.com/pdf/ibm/6580_Displaywriter/S241-6248-3_Displaywriter_6360_6580_Product_Support_Manual_Feb1983.pdf
> >
> > I'd like to actually store data to these disks in the same manner the
> > original systems did, and I'm proficient in hardware/firmware. Has anyone
> > made a controller for this already? How about emulating the filesystem?
> >
> > Any help is appreciated, and I'd open-source whatever I make (PCBs,
> > firmware, etc.).
>
> Are you talking about the disk unit for the Displaywriter (6580)?
>
> Those don't use what you'd call a general-purpose filesystem in their
> native mode (although there was a version of CP/M 86).  The DW
> filesystem is very specific to that word-processing application and
> probably not useful for general-purpose applications.  And, of course,
> the character code used is EBCDIC.
>
> --Chuck
>
>
>

Re: IBM 6360 - Filesystem(ish) info?

[Anders Nelson via cctalk]

Ok, are there command/response listings for these controllers, or one for
this exact unit?

On Tue, Feb 19, 2019, 1:29 PM Eric Smith  From a rather cursory examination of the manual, it looks like they put
> the controller in the diskette unit itself ("Diskette Signal Cable", figure
> 8-22), so you should be able to hook it up to just about any
> microcontroller. It's probably a 765/8272 style controller.
>

Re: IBM 6360 - Filesystem(ish) info?

[Anders Nelson via cctalk]

Hi Ali,

I'm planning on a USB controller, but I've seen ISA projects that are also
microcontroller based so I think it wouldn't be awfully difficult to
replace the USB data pipe with an ISA one.

Zooming out, I have a list of USB controllers to build:

- Kennedy 9800 tape drive
- IBM 6360 8" floppy drive
- IBM  5 1/4" floppy drive

My friends think it's silly, and they're probably right. =P

On Tue, Feb 19, 2019, 1:18 PM Ali  >
> > Now that I have my glorious disk toaster (2D model I think, says "2D"
> > on
> > the drive levers), I want to build a controller for it. I found pinouts
> > and
> > some description of the media organization here:
> >
> > http://bitsavers.trailing-edge.com/pdf/ibm/6580_Displaywriter/S241-
> > 6248-3_Displaywriter_6360_6580_Product_Support_Manual_Feb1983.pdf
>
> Congratulations! Those are nice looking drives. The problem of course is
> they don't work with anything "standard".
>
> > I'd like to actually store data to these disks in the same manner the
> > original systems did, and I'm proficient in hardware/firmware. Has
> > anyone
> > made a controller for this already? How about emulating the filesystem?
>
> Wow. That is going to be big endeavor A question what is your target
> system (i.e. are you planning on implementing this on a controller
> connected to a modern system w/ USB or are you planning on a nice ISA card
> so these drives can be used on older systems?) I wish I could help you
> technically but my background is far removed from engineering... However, I
> will follow with great interest specially if you go the ISA route...
>
> -Ali
>
>

IBM 6360 - Filesystem(ish) info?

[Anders Nelson via cctalk]

Hi friends,

Now that I have my glorious disk toaster (2D model I think, says "2D" on
the drive levers), I want to build a controller for it. I found pinouts and
some description of the media organization here:

http://bitsavers.trailing-edge.com/pdf/ibm/6580_Displaywriter/S241-6248-3_Displaywriter_6360_6580_Product_Support_Manual_Feb1983.pdf

I'd like to actually store data to these disks in the same manner the
original systems did, and I'm proficient in hardware/firmware. Has anyone
made a controller for this already? How about emulating the filesystem?

Any help is appreciated, and I'd open-source whatever I make (PCBs,
firmware, etc.).

Thanks!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com

Re: Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

Gone, I'm sorry to report!

--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Tue, Feb 19, 2019 at 10:05 AM Derek Newland 
wrote:

> There are many pictures on their Facebook page
> <https://www.facebook.com/KemnerEnterprises/photos/>. Of particular
> interest, is this one of an IBM System/34 chassis:
>
> https://www.facebook.com/KemnerEnterprises/photos/a.1770653292985604/1768376576546609/
>
> On Sat, Feb 16, 2019 at 1:52 PM Anders Nelson via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> Hi everyone,
>>
>> I heard Kemners Surplus in Pottstown, PA was going away so I decided to
>> pay
>> them a visit. I'm taking pictures of as much vintage computing gear as I
>> can as we speak. I'll be here until they close today at 5pm EST, so if you
>> see something you like feel free to give them a call and I'll help them
>> navigate.
>>
>> Photos updated as I walk through, here:
>>
>> https://photos.app.goo.gl/4Q8Jx7n36fmVczLN8
>>
>> If you see something you like it'd be great if you could check if I'm
>> interested first until I'm finished today. ;]
>>
>> Hope this helps someone, they shut down soon!
>>
>
>
> --
> *Derek Newland* | (828) 234-4731 | derek.newl...@gmail.com
>

Re: Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

True, there were large reels on a rack, most were educational films.

There was a room dedicated to tube radios, most were in very rough shape
aesthetically.

Also a room with reel-to-reel audio decks from AKAI, Teac and other brands
that looked nice. Phonographs of varying decade, a bunch of camcorders and
film cameras of various format.
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Mon, Feb 18, 2019 at 11:47 AM dwight via cctalk 
wrote:

> There were a couple hp XY plotters that had the mylar plate delaminating.
> I've reworked these with model airplane mono coat. I'd be interested in one
> of these if they'd not been to far away.
> If you do a search, there is also a youtube video of a more extended walk
> through. The fellow was also a collector of 16mm films. He has racks and
> racks of them. He has a lot of tubes and a few old radios. The fellow doing
> the video was not to interested in these things.
> Dwight
>
> 
> From: cctalk  on behalf of John Blake via
> cctalk 
> Sent: Sunday, February 17, 2019 4:57 PM
> To: cctalk@classiccmp.org
> Subject: Re: Kemners Surplus - Real time walkthrough
>
> Any idea what that blue Data General machine was?  Some kind of terminal
> server?
>
>

Re: Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

One final note:

I didn't get pictures of these, but Kemners has probably 20-25 IBM external
5 1/4" floppy drives, about half of them are 360K and half are 1.2MB. Two
of the 360K drives are NIB, wrapped in their original plastic.

=]

On Sat, Feb 16, 2019, 5:37 PM Anders Nelson  Well, I got outta there with:
>
> - IBM 6360, $45
> - IBM 4868-002, $20
> - 10 pack DSDD soft sector 8" floppies, $10
> - Life magazine from 1941 with pretty lady on the cover, $5
>
> Did I get swindled or is this par for the course?
>
> On Sat, Feb 16, 2019, 4:56 PM Peter Cetinski 
>>
>> > On Feb 16, 2019, at 4:43 PM, Anders Nelson via cctalk <
>> cctalk@classiccmp.org> wrote:
>> >
>> > They have until the end of June 2019.
>> >>
>>
>> Just my $0.02.  When I was there last year they said the same thing.  And
>> prices were eBay level.  If prices aren’t coming down a lot I suspect they
>> may get their lease “extended”.
>
>

Re: Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

Well, I got outta there with:

- IBM 6360, $45
- IBM 4868-002, $20
- 10 pack DSDD soft sector 8" floppies, $10
- Life magazine from 1941 with pretty lady on the cover, $5

Did I get swindled or is this par for the course?

On Sat, Feb 16, 2019, 4:56 PM Peter Cetinski 
> > On Feb 16, 2019, at 4:43 PM, Anders Nelson via cctalk <
> cctalk@classiccmp.org> wrote:
> >
> > They have until the end of June 2019.
> >>
>
> Just my $0.02.  When I was there last year they said the same thing.  And
> prices were eBay level.  If prices aren’t coming down a lot I suspect they
> may get their lease “extended”.

Re: Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

They have until the end of June 2019.

On Sat, Feb 16, 2019, 4:24 PM William Donzelli  Also, can you find out when they plan to close their doors and/or call
> the scrapper? A timetable?
>
> Thank you for your effort so far.
>
> --
> Will
>
> On Sat, Feb 16, 2019 at 4:20 PM Anders Nelson via cctalk
>  wrote:
> >
> > More photos posted to the album with some NIB DEC boards, look like a
> > motherboard and CRT board, two of each.
> >
> > On Sat, Feb 16, 2019, 1:51 PM Anders Nelson  > wrote:
> >
> > > Hi everyone,
> > >
> > > I heard Kemners Surplus in Pottstown, PA was going away so I decided to
> > > pay them a visit. I'm taking pictures of as much vintage computing
> gear as
> > > I can as we speak. I'll be here until they close today at 5pm EST, so
> if
> > > you see something you like feel free to give them a call and I'll help
> them
> > > navigate.
> > >
> > > Photos updated as I walk through, here:
> > >
> > > https://photos.app.goo.gl/4Q8Jx7n36fmVczLN8
> > >
> > > If you see something you like it'd be great if you could check if I'm
> > > interested first until I'm finished today. ;]
> > >
> > > Hope this helps someone, they shut down soon!
> > >
>

Re: Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

More photos posted to the album with some NIB DEC boards, look like a
motherboard and CRT board, two of each.

On Sat, Feb 16, 2019, 1:51 PM Anders Nelson  Hi everyone,
>
> I heard Kemners Surplus in Pottstown, PA was going away so I decided to
> pay them a visit. I'm taking pictures of as much vintage computing gear as
> I can as we speak. I'll be here until they close today at 5pm EST, so if
> you see something you like feel free to give them a call and I'll help them
> navigate.
>
> Photos updated as I walk through, here:
>
> https://photos.app.goo.gl/4Q8Jx7n36fmVczLN8
>
> If you see something you like it'd be great if you could check if I'm
> interested first until I'm finished today. ;]
>
> Hope this helps someone, they shut down soon!
>

Re: Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

They have probably 25 boxes of 10, 8" DSDD floppies each that are still in
their sealed packaging if that's of interest!

On Sat, Feb 16, 2019, 2:29 PM Grant Taylor via cctalk  On 2/16/19 12:16 PM, Anders Nelson via cctalk wrote:
> > The last there was proactive about saying prices are negotiable, and you
> > could expect "up to 50%" off.
>
> Hum.
>
> I feel like that's not sufficient to peak my interest in some of the
> things.
>
> I'm particularly interested in the IBM PS/2 stuff, but there's not
> enough information / details to speculate on short notice from afar with
> unknown prices and shipping.  :-/
>
> I do think that's the biggest collection of Model 80s that I've seen in
> one place in quite a while.
>
> I'd be really curious what cards are in them.
>
> Thank you for the pictures and the heads up Anders.
>
> > I'm not about to pay up to $1K for one of those corroded disk packs,
> so...
>
> Ya.  Some of the equipment looked fairly rough.  I suspect a good
> cleaning will help.  But it's difficult to tell what condition and if
> it's just surface dirt or if the problems run deeper.
>
>
>
> --
> Grant. . . .
> unix || die
>

Re: Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

The last there was proactive about saying prices are negotiable, and you
could expect "up to 50%" off.

I'm not about to pay up to $1K for one of those corroded disk packs, so...

On Sat, Feb 16, 2019, 2:11 PM William Donzelli  Probably the biggest question everyone has is if the prices are
> reasonable for a place about to go under.
>
> --
> Will
>
> On Sat, Feb 16, 2019 at 1:52 PM Anders Nelson via cctalk
>  wrote:
> >
> > Hi everyone,
> >
> > I heard Kemners Surplus in Pottstown, PA was going away so I decided to
> pay
> > them a visit. I'm taking pictures of as much vintage computing gear as I
> > can as we speak. I'll be here until they close today at 5pm EST, so if
> you
> > see something you like feel free to give them a call and I'll help them
> > navigate.
> >
> > Photos updated as I walk through, here:
> >
> > https://photos.app.goo.gl/4Q8Jx7n36fmVczLN8
> >
> > If you see something you like it'd be great if you could check if I'm
> > interested first until I'm finished today. ;]
> >
> > Hope this helps someone, they shut down soon!
>

Re: 8-Update

[Anders Nelson via cctalk]

Oh boy, how did I miss that someone has created a front panel PCB layout
for a PDP-8/e?

Can you ask Vince to share that design please?

On Tue, Dec 18, 2018, 6:08 PM Paul Birkel via cctalk  >I have an .slt for the PDP-8/e lever
> >Rod
>
> Please publish/share?
>
> paul
>
>

Kemners Surplus - Real time walkthrough

[Anders Nelson via cctalk]

Hi everyone,

I heard Kemners Surplus in Pottstown, PA was going away so I decided to pay
them a visit. I'm taking pictures of as much vintage computing gear as I
can as we speak. I'll be here until they close today at 5pm EST, so if you
see something you like feel free to give them a call and I'll help them
navigate.

Photos updated as I walk through, here:

https://photos.app.goo.gl/4Q8Jx7n36fmVczLN8

If you see something you like it'd be great if you could check if I'm
interested first until I'm finished today. ;]

Hope this helps someone, they shut down soon!

Re: decgraphic brochures on eBay

[Anders Nelson via cctalk]

I'd love a link to the images of that decgraphic brochure when you scan it!
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Wed, Jan 30, 2019 at 2:53 PM Jason T via cctalk 
wrote:

> On Wed, Jan 30, 2019 at 1:48 AM Al Kossow via cctalk
>  wrote:
> >
> > Is anyone here bidding on them that intends to scan them?
> > I won't snipe them if that's the case
>
> The GT44 User Guide?  Or is there another auction?
>
> That one is too many $ for me.
>

Re: 3850 media

[Anders Nelson via cctalk]

Peter, was that what you were looking for?

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Mon, Jan 14, 2019 at 10:38 PM cctalk via cctalk 
wrote:

> I believe someone was looking for these recently.
>
>
> https://www.ebay.com/itm/IBM-3850-media-cartridge-1970s-vintage/123591889131
>