On 4/27/22 10:51, Craig Ruff via cctech wrote:
> Having gone through many mathematics courses it was common to also place a
> slash on the letter Z to distinguish it from the numeral 2. Also for persons
> from Europe where they slashed the numeral 7 to distinguish it from a numeral
> 1 that
I'll only mention that there were ICs that could interface to both
MFM/ST506 hard drives as well as floppies (System/3 MFM).
An example would be the SMC HDC9234, "Universal Disk Controller".
Pretty cool chip for the time; has full 24 bit DMA address capability.
But different register/controller
On 4/10/22 12:23, Martin Bishop wrote:
> Chuck
>
> My error, you said 20 mA current loop, I bowdlerised it as parallel port. I
> have a punch with a parallel interface ... I can't recollect ever using a
> current loop interface on equipment, although I have met many in old
> documents. 4 ..
On 3/16/22 13:37, Will Cooke via cctech wrote:
If the question is being asked by a person of a certain vintage, I can
understand the "why" of it. Gone are the days when you simply switched
off the AC power when you were finished.
Nowadays, everything from cell phones to Smart TVs go through a
Perhaps even rarer were the EBAM tubes that CDC worked with during the
1970s. I recall seeing a 6' rack of a complete assembly sitting in a
hallway at ADL around 1974. If CDC followed the dictates of management
then, the unit was probably utterly demolsihed before being sold as
scrap metal.
On 11/6/21 10:24 AM, David Gesswein via cctech wrote:
> On Fri, Nov 05, 2021 at 10:13:48PM -0500, David Williams wrote:
>> I have a TI monitor that has a power cord that is becoming sticky and gummy
>> and I'm looking at what to do with it.
>> Any other suggestions on dealing with the cord
On 8/8/21 3:38 PM, Randy Dawson via cctech wrote:
> I found a few of the databooks here:
>
> https://usermanual.wiki/search.php?q=motorola%20semiconductor%20reference
>
Randy, if you're looking for Moto databooks, Al has archived a pile of
them on bitsavers:
On 8/7/21 5:50 PM, r.stricklin via cctech wrote:
> Anyone have an early ‘80s Motorola semiconductor reference manual? I am
> attempting to repair a Boschert power supply from ~1983 that is full of
> Motorola parts marked as 1027 (DO-42ish), 1077 (TO-3ish), 1078 (DO-5ish),
> etc. It would be
On 8/5/21 8:23 AM, Jay Jaeger via cctech wrote:
>
> Also, before starting (after baking and cool-down) I unspool maybe 25
> feet of tape onto a clean surface to make sure it isn't sticking. If it
> does, I let it sit for a few hours, and then bake it again. Have not
> had to bake for additional
Whoever does it, I have a few suggestions when it comes to 40+ year old
tapes.
1) Bake the thing at 58C for a day or two. It might just prevent you
from staring at a tape stuck to the head and a pile of brown dust at the
bottom of the drive. (Before you start, make note of the brand and type
of
On 8/2/21 8:11 AM, James Liu via cctech wrote:
> Thanks for feedback and offers to assist.
Happy to contirubte.
> For some background, Tini Veltman developed Schoonship in the 1960's
> at CERN on the CDC 6600. My understanding is that he more or less
> insisted on coding in assembly since he
On 7/31/21 8:08 AM, Jon Elson via cctech wrote:
I'll add a thought that if this is a CDC 6000-system tape written in the
1970s, it could well be 7-track, regardless of the manufacturer's label.
Up through the 1970s, 7 track tape drives were very common on CDC systems.
--Chuck
On 7/31/21 8:08 AM, Jon Elson via cctech wrote:
> Where are you? I have a CDC Keystone drive that worked last time I
> fired it up,
>
> and I have it interfaced to a Linux PC. I'm in Missouri.
I wonder if the OP is in the Netherlands, Schoonschip being a Dutch product.
In any case, I'd
On 7/21/21 2:42 PM, Jules Richardson via cctech wrote:
> On 7/21/21 12:51 PM, r.stricklin via cctech wrote:
>>
>>
>>> Regarding your "IDE HDDs were extremely rare" comment, did *anyone*
>>> other than Quantum release an IDE drive in that 5.25" form factor? I
>>> can't think of any, everything else
Going back to the time around 1960, I'd like to venture the opinion that
most data processing of the time was performed with unit-record
equipment. That is, sorters, reproducing punches, interpreters,
accounting machines, etc., none of which were programmed by "software",
but by wiring plugboards
Aside from the very general Algol report and the Iverson book on APL, I
have to admit that most of my programming knowledge came out of
manufacturer's manuals, specific to a maker's systems.
The APL book was, at the time, pretty much useless for writing any sort
of serious code until you got hold
The simplest thing, if you can locate one, is to find a WD1000/WD1001
controller board and hook it to a PC. Chances are overwhelming that it
was used to write the SA100x in the first place.
My first 5150 hard drive used such a setup--an SA1002, a WD1001 and a
very small hand-wired ISA card for
On 11/24/20 4:02 AM, Mattis Lind via cctech wrote:
> I found a three RX01 disk set for a Fortran IV system V2.5 for RT-11.
>
> I dumped the contents and it is available here:
>
> https://drive.google.com/file/d/12VXh4wk3Zo_fSGRtLPHwrJg6ui3pwVd-/view?usp=sharing
I believe (not sure about
On 11/10/20 9:25 PM, Mike Stein via cctech wrote:
> Same here. Also works for soldering header pins etc.; stick a matching
> connector on the other side of the board and they stay flush and
> perpendicular.
Nice tip, but I thought that most folks knew about the
matching-connector thing! I guess
On 10/4/20 10:51 PM, J. David Bryan via cctech wrote:
> On Sunday, October 4, 2020 at 16:00, Chuck Guzis via cctalk wrote:
>
>> A 16MB tape block is impossibly large in any case.
>
> The HP 3000 mag tape diagnostic attempts to write a single record from BOT
> to EOT, which unfortunately fails
In fact, is there any standard for floppy disk metadata container files?
I'm not aware of any.
--Chuck
On 7/18/20 7:37 PM, Marc Howard via cctech wrote:
> Hi,
> I live in the Bay Area. Maybe those of you with connections to CHM could
> see if we could read the tapes on the 1401. Or maybe one of you has a 7
> track driver in your junk file. All we really would need is the head and
> we could put
On 7/13/20 11:59 AM, Will Cooke via cctech wrote:
> Thanks. I found the one(s) on Simtel and they weren't the right ones. I
> "think" the 1.1 that is on there is for the IBM PC (8088) or maybe the Z-80.
> In any case, I think it's been found.
>
The github one:
All I've been able to find is the source for 1.1 on github, which was
laboriously reconstructed from an OCR of the original article.
--Chuck
On 7/13/20 10:07 AM, Will Cooke via cctech wrote:
> Unfortunately, no. That was one of the first places I looked. They have the
> 2.1 version from the Small C handbook (James Hendrix) and some other
> derivatives, but not the original 8080 version 1.0.
>
> Thanks,
> Will
SIMTEL20 claims to
On 7/13/20 5:22 AM, Will Cooke via cctech wrote:
> I'm trying to find source files for the very first, original, ver 1.00(?)
> small C compiler. I have the DDJ issue with the printed source (minus the
> assembly language runtime libs.) I have found all sorts of derivative works,
> but I
On 6/25/20 4:12 PM, Jon Elson via cctech wrote:
> On 06/25/2020 05:29 PM, W2HX via cctech wrote:
>> Does ANYONE have any idea what these 4 wires are connected to and why?
>> And anyone give any odds about whether these 4 wires will prevent this
>> IDE-SD converter from working?
>>
>>
> Temperature
On 8/30/19 7:24 PM, John Ames via cctech wrote:
> Ran into this at the electronics-surplus store just down the way from
> my workplace and grabbed it on the cheap. I don't actually know what
> it *is,* but the labels on the switches make it look a *hell* of a lot
> like a 16-bit general-purpose
On 8/12/19 8:11 AM, Douglas Taylor via cctech wrote:
> The bad news is that the cable lengths must be short to use the Qualstar
> 1260 with a PDP11, the good news is that I can lift and carry the tape
> drive! For many of us in this hobby that it is extremely important.
>
> After looking at
On 8/11/19 8:51 PM, Douglas Taylor via cctech wrote:
>
> The TC02 is an Emulex TS11 emulation for pertec interface tape drives.
> The J1 and J2 are sort of standard terminology, don't know why.
Ah, the *Emulex* TC02. You had me going there--DEC also has a DECtape
controller called the TC02.
On 8/11/19 6:00 PM, Douglas Taylor via cctech wrote:
> I just looked at the TC02 and the Qualstar, there are termination
> resistor packs on each. The Qualstar has a bunch of 74LS240 IC's near
> the J1 and J2 pertec interface cables. The TC02 has a bunch of 74LS374
> chips near the J1 and J2
On 8/11/19 9:11 AM, W2HX via cctech wrote:
>> All of my Pertec tape drives (in the past) were located in
> a differentrack from the actual computer so the cables were
> always over 10' long and usually close to if not 20'. Never
> had a problem.
I stand by my commentary re Qualstar 1xxx drives.
On 8/10/19 9:45 AM, Douglas Taylor via cctech wrote:
> I bought the long cables off ebay, so they have to be good? Right? I
> think the short cables came from a hamfest.
>
> The cables can be fairly long, I remember interfacing a TU80 to an
> Emulex QT14 (maybe) and the DEC cables were round and
On 8/9/19 9:05 PM, Douglas Taylor via cctech wrote:
> I have a question about cable length - any electrical engineers in the
> house?
>
> Connected a Qualstar 1260 tape drive to an Emulex TC02 qbus tape
> controller in a pdp-11/53. The interface is pertec with 2 50 pin cables.
>
> When I use a
On 4/10/19 11:29 AM, Fred Cisin via cctech wrote:
> On Wed, 10 Apr 2019, Chuck Guzis via cctech wrote:
>> Aw, that's too bad! The original Model I (CADET) 1620 had a console
>> typewriter (was it based on the IBM Model B electric?) that gyrated
>> enough, particularl
On 4/10/19 10:35 AM, Dave Babcock via cctech wrote:
> To all,
>
> The Computer History Museum's IBM 1620 Jr. project has already done
> this. We have converted an IBM Wheelwriter 1000 electric typewriter
> into a computer terminal. The conversion consists of a custom PCB with
> an Arduino
On 4/8/19 9:06 PM, Jeff Woolsey via cctech wrote:
>> I've noted earlier that the vinyl "hanger strips" for 1/2" magnetic tape
>> have been degrading, becoming brittle and simply breaking away,
>> sometimes in small particles.
>
> I have about a hundred tapes from various contributors, and have
On 2/23/19 10:18 AM, Carl Claunch via cctech wrote:
> In the early 1970s a socket to hold multiple DIP chips was being sold under
> the brand name DipStik. Up to six chips were inserted in a trough in the
> socket, a top screwed on with thumbscrews on the ends. It had solder lugs
> on the top and
On 12/28/18 12:42 PM, Peter Van Peborgh via cctech wrote:
> Gentlemen of advanced years who can remember CDC, cradle of Cray.
>
> Can you tell me which CDC computer type these three boards belonged to? It
> is for labeling purposes in my personal museum.
>
> https://postimg.cc/crJHv3Lt
>
On 12/21/18 11:32 AM, allison via cctech wrote:
> And the automotive reference was not it. It was the straight as in not
> later lettered
> versions. Best similar use is: Whiskey straight, water on the side.
Could be--but I was pointed out that "straight eight" was an automotive
term familiar
Hi Gerard,
Yes, it's been there for some time. Al K. uploaded it upon my request.
It turns out that my guesses about the architecture based on floppy disk
data were correct!
Thanks,
Chuck
On 09/25/2018 07:47 AM, GerardCJAT via cctech wrote:
> @ Chuck,
>
> I know you know about the FST1
I suspect that it's from a trainer of some sort.
Stewart-Warner quad 2-input NAND DTL stuff. So probably not RCA.
--Chuck
On 07/12/2018 09:05 PM, David C. Jenner via cctech wrote:
> Would Chuck's temperature and Al's oven be appropriate for old magtapes,
> too?
My "cooker" is home-built and heavily insulated. It has a 75W
incandescent for heat and a low-speed fan for circulation. I use a PID
controller to keep the
On 05/22/2018 10:46 PM, Lars Brinkhoff via cctech wrote:
> This is with a microEclipse CPU, right?
>
> I'm surprised the Nova/Eclipse architecture doesn't get more love.
> It seems quite pleasant.
>
As I recall--and please correct me--DG was extremely hostile to the
notion of third parties
On 11/18/2017 01:21 PM, Aaron Jackson via cctech wrote:
> You might be surprised how many LCD monitors support SoG. I have several
> iiyama LCD panels which work fine with a 3100.
>
All of my NEC Multisync LCD ones do--some even have 5 BNC connectors for
video input.
--Chuck
On 11/17/2017 09:17 AM, allison via cctech wrote:
> Also the Syquest 270mb IDE/parallel port cartridge disk. I have one
> that works
> and over a dozen carts. Its still in use in a ITX box using the IDE
> interface. After
> two decades of use it seems solid.
I've left out the non-floppy
On 11/03/2017 05:40 PM, Brian Walenz via cctech wrote:
> I'm assembling a PDP-8/a from a pile of parts, but I'm missing the entire
> AC power entry assembly, as shown in
> http://www.retrotechnology.com/restore/8a_trans_gnd0.jpg. Does anyone know
> what the 6-pin connector is? Even better, does
On 10/02/2017 10:03 AM, Alan Perry via cctech wrote:
> Here is a complete quote from the minutes:
> "Jim McGrath of Quantum defined his company's interest as being
> primarily in the ability to embed SCSI into a drive without there being
> a physical SCSI bus present. He described some problems
On 09/30/2017 11:50 AM, Richard Cini via cctech wrote:
> I’m in the process or restoring a Seattle Gazelle for the Vintage
> Computer Federation and one of the disks that it came with had
> “Norton Utilities” written on it. I’ve imaged the disk but I’m not
> entirely sure what system it was for,
On 06/07/2017 10:47 AM, Paul Koning via cctech wrote:
> 6600 core memory is documented in great detail in the training manual
> which is on Bitsavers. It has conventional diagonal sense lines. It
> does have some interesting design attributes, though. For one thing,
> it has pairs of inhibit
On 03/31/2017 06:15 PM, Jon Elson via cctech wrote:
> I have a project I do from time to time using 128-lead 14mm TQFPs
> with 0.4mm lead spacing. I use a stereo zoom microscope with a
> home-made LED ring light. First, I rub the pads with a pencil eraser
> to remove oxidation caused by reflow
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