hello,
I would ask for an advice on where buy the Misumi rubber bands.
I'm located in Italy.
Thanks
Andrea
Guy,
I agree that accessing data in blockram (synchronous with fixed latency) is
really easier than accessing it from RAM (asynchronous with variable latency).
Anyway I'm weighting the "cost" of additional complexity, which in change would
allow to spare on Zynq cost.
In any case memory access is
Guy,
I understand that cylinder command has no particular timing requirements, while
head command must be effective within microseconds. My doubt is, RAM access on
high performance port could be fast enough to satisfy also the latter.
In case it couldn't or was not assured, I think the best strat
Guy,
I agree on keeping Linux out of the loop, to allow fast access on head
location, selection.
However, I'm not convinced on the fact that a whole cylinder must be on
blockram to achieve this. Given that ram access is fast (on Zynq with PL
working at 200MHz and HP port at 64bits I'm running at
It would be far easier to modify a driver for a selected media, rebuilding the
controller electronics for the purpose.
Anyway it would be a tough work, useful only for a single media type.
Andrea
Apr 17, 2022 20:12:28 Paul Koning :
>
>
>> On Apr 17, 2022, at 1:28 PM, shad via cct
hello,
there's much discussion about the right method to transfer data in and out.
Of course there are several methods, the right one must be carefully chosen
after some review of all the disk interfaces that must be supported. The idea
of having a copy of the whole disk in RAM is OK, assuming t
Hello,
I'm a decent collector of big iron, aka mini computers, mainly DEC and DG.
I'm often facing common problems with storage devices, magnetic discs and tapes
are a little prone to give headaches after years, and replacement drives/media
in case of a severe failure are unobtainable.
In some ca
Hello Rob,
FreeCAD is nice for modeling 3D shapes.
For 3D printing, depending on the technology of 3D printer, you need to process
original model to convert compact sections into hollow honeycomb structure, and
add small plastic bars into empty volumes to support the model while it's
printed.
I
> The ready lamp flashes not when the servo burst is >visible, but when the
heads are just before it.
> Why? Well, I probably set the gain too high on the read/write module.
Hello,
I'm sure you read the manual, however I add some explanation to be sure.
The best head position is not where a servo
dear all,
thanks for the useful informations!
So now a question comes to mind...
what is the best utility for Linux to be used to read and archive tapes?
Thanks
Andrea
Hello,
I have a question about 9 track tapes and block sizes.
What I know is that tape is subdivided in files by means of marks, and each
file is subdivided in blocks of equal size.
Programs like tar use a specific block size to create files on tape.
However files can have different block sizes lik
Hello,
this tool is really similar to "rdfind", which compares file sizes and
content, independently from file name, and is able to create a list of
correspondence, delete duplicate files, and create symbolic links to the
single instance.
This can work on large amounts of files, even on complex dir
Hello,
definitely you should be able to fix it.
This kind of problem is caused by the missing thickness of the rubber
stoppers of the positioner, which became goo in the years.
You have two ways to solve this problem.
First of all, remove the disk top cover plate in clean room, locate the
positione
Hello,
well maybe my memory has blank spots.
I have two CDC Lark Disk modules I would like to revive, they are in good
shape, but only one has a cartridge included, and they are not identical.
Not sure if the other one could be employed without cartridge.
I never found a manual with exact model cor
Hello,
I also was searching about a clear SMD specification years ago, I found
something in disk documentation from CDC, but doubts remain, because some
disks call the interface SMD, some other CMD, never understood the
difference...
Andrea
Hello,
first of all, I would advice to READ the original eproms and compare with
known good.
This will possibly spare a lot of efforts...
Andrea
Hello,
yes, bitsavers and the efforts of Al are invaluable!
Considering that I'm referring only to DEC PDFs, but the archive is indeed
far more vast then this, the time to maintain all of it is way over what
normal people would dedicate to free time jobs... simply that could mean
that Al is a super
Hello,
I also have a bunch of manuals, mainly for rt11, which aren't available in
bitsavers.
I always thought of bitsavers as the "whole" archive for DEC stuff, however
time ago, sorting these manuals, I found they where available only on Manx
or Antonio Carlini's archive.
Many manuals then are ava
Hello Peter,
you have a nice list of interesting things.
I'm very interested in DEC machines,
which I collect and repair for preservation purposes.
Among others, I could be interested in those:
DECmate
assorted QBUS boards (do you have a list?)
VAX 4000/90A
VAX 4000/96
VAX 4000/100A
VAX 4000/105
Hello,
maybe there's a short between RXD and TXD, or possibly the GND is
unconnected...
This could cause an echo on the cable, and while the console is echoing
too, this give an infinite repetition, only ended by the limited console
buffer size...
Andrea
Hello,
I'm in the process of cleaning and hopefully restore to operation of a DEC
R80.
The unit has some minor sign of corrosion, however it's VERY dirty, even
inside the hood.
The filters are obviously to be removed and replaced, as they are
disintegrating.
Also foam parts between the boards must
Hello,
do you know the people who made the video?
I think the factory is the Satilai in Saronno.
Andrea
Hello,
I have two DG One, they are however not identical.
One is the older version, the other is more recent and have a different
display.
I never heard of a keypad accessory, it would be a very nice piece indeed!
I should check for connectors on the back?
Thanks
Andrea
Hello,
I always have been amazed by the complexity and peculiarity of
fixed/removable hybrid discs like DEC RC25 and CDC 9457.
Looking at some specifications found on the web, these drives look quite
similar each other, even if these are completely different on an exterior /
interface point of view
Hello,
this is what I found:
These ROMS can
be read on an EPROM programmer as an MC68766 part,
as long as the programer strobes CS or OE when reading
each consecutive address. Most will do that.
They can be directly replaced with pin-compatible EPROM
MC68766 or MCM68766C35 but these are obsolete
Hello,
as other said, there's always demand for old disks, specially if working.
The Micropolis are prone to death due to rubber of the head arm going to
goo over time... but it can be repaired with some effort.
I myself would take some of these disks for shipment, if you are in EU.
Thanks
Andrea
Kobo have a quite plain Linux, run on iMX processors, and are very easy to
modify/script, and last but not least, to unbrick in case of severe
problems.
In many models, the internal memory is an SD card, so it can be expanded
easily.
Then you have also external SD.
On the software side, try koread
Hello,
I'm interested in the M8739.
I sent you an email.
Thanks
Andrea
Hello,
I'm very interested in any media / documentation for Aviion machines too (I
have two of them).
Bruce: nice to hear from you!
>From your affirmation, I suspect there will be a very happy ending!
Any good news also for older OS for Nova and Eclipse (DOS, RDOS, AOS)?
Thanks
Andrea
Hello,
maybe you have also a dump for a 4000-100A ?
I have a motherboard which seems to have problems to Bcache or Pcache, and
another one which I took as replacement, which has a very old version.
I wonder if there's a way to dump the firmware in some way from the
non-working one, then update the
Hello,
I sent you an email about the Votrax system.
Thanks
Andrea
Hello,
this kind of keyboards was made using small pieces of conductive rubber to
close the circuit designed on the PCB.
The rubber was an uniform compound, so even with severe usage, i.e. high
consumption, the conductivity remained constant.
However, in more recent / cheaper products, the rubber i
Hello Mark,
I sent you an email some hours ago about the books, not sure if it got lost
in spam...
I would buy them all.
Thanks
Andrea
Hello,
I'm not an absolute expert, but I successfully fixed a couple of RL02 in
the past.
Adjustment to the head is only useful for azimuth, I think. The radial
position will be adjusted continuously using the servo tracks, so there's
no absolute position adjustment at all.
If the drive fails durin
Hello Adrian,
do you think that you could ship one of the LA100-CA to Italy?
Thanks
Andrea
Hello,
I'm searching a source of good tape for a TU80 and a TU81 I have.
I acquired some media from eBay, but all of that suffers of sticky problem
and is unusable.
Anybody has some to sell, or for give an advice of a seller of proven good
tape?
I wish prefer a seller in EU or UK, but even overseas
Hello Paul,
I have a VT30 board set, it would be nice to receive a copy, if not the
original, of related bits you have!
Maybe also some documentation?
Thanks
Andrea
Hello,
I also have a Dilog SU723A, but never managed to find any docs for it.
My board is revision D.
It works be very nice to find something.
As the MSCP / TMSCP selection is only a matter of firmware, I wouldn't be
surprised if the MSCP SU726A was the same board with different PROM.
Andrea
Hello,
I have some doubt about DEC tape units and related interfaces.
What I know about (right or wrong, please correct):
- TU80 is a Pertec drive, it needs M7454 (unibus, TS11 driver) which is a
modified Dilog DU132. No option for QBUS.
- TS05 is a Pertec drive, it needs TSV05 (qbus, TSV05 drive
Further analysis:
A106 =STTA106/U
2X =MMBT4401
2T =MMBT4403
Good luck!
Andrea
Hello,
while I can confirm that the bigger black with two pins is a diode, I'm not
sure what kind of diode it is, as it could be bipolar, Schottky or Zener.
About the smaller black components with three pins, they could be
transistor or diodes (single or double, with common cathode, common anode
o
Hello,
the vertical heat sinks for the TO220 with this design are fairly common, I
saw them many times on various boards.
However, as they are simply aluminum parts, you can clean them for sure.
After removing the screw, you could try simply with an hard brush.
If badly corroded, remove the bubbles
Hello,
explanation is easy.
Old electrolytic will have a bigger current leakage, i.e. the unwanted
amount of current which flows through it.
With resistances having high value, the small current is completely eated
by the leakage, thus never charging the capacitors.
As you are connecting the probes
Hello,
I don't have in mind the exact image of the filters of PDP11, but in some
case the filters are repairable in some way.
The hard problem of course is to dismount it.
Sometime these are stained iron foil boxes, filled with inductors and
capacitors, then some gel insulator, and finally soldered
hello,
well it's difficult without the piece in hands to understand the circuit,
and without the schematic, but I could give a try.
1)
On a switching PSU, only one output is really stabilized, here it seems 5v.
The other outputs are "unregulated", but in some way related to the
stabilized one, for
leaded solder = AgPb alloy
Hello,
in my experience SMD components doesn't need a presoldering operation at
all, because pins are already stained or golded, thus very solderable.
Plus the extra heat could let the pin move inside the plastic, or add
somehow excessive thickness when positioned on the PCB.
In my experience the b
Hello,
I don't have any Andromeda hardware, but I think an easy solution would be
to ask to the eBay seller to ask to the buyer if he would be available to
be in contact with the group.
After all, it's very likely that he could be an enthusiast like us.
Then ask about imaging the disks...
Hoping t
Hello Rob,
please try to check the status of the OE input, comparing it to the other
motherboard.
Andrea
Hello Tony,
I read you have an R80 for 730.
I have such machine, unfortunately the 80 is broken, I suppose the HDA is
gone.
The belt is also almost gone.
That's why I would really like to find replacements.
I probably don't need the servo card (I hope it's not broken), so if Greg
takes the board, I
Hello,
now you could try to check the voltages again, just to be sure the fault is
not on the 245.
Following the traces is of course obviously difficult, but if the board is
really only two-sided (no internal signal layers), components are not too
high, and you have a flatbed scanner, you could sc
Hello Rob,
if you are uncomfortable with soldering, I can replace the IC for you.
Just ship me the board, I will desolder it.
bye
Andrea
Hello,
given the rules, I think the winner could be me! :)
I hope it would not cost me a liver for shipment
As I mentioned in my direct email to you,
if the DECtalk business goes to the end, I would be interested also on the
couple of Data General memory board, these could fit in a Nova I have
Hello Anders,
thanks for your offer!
I wrote you an email, I would be glad to receive the DECtalk!
Andrea
Hello,
I would really like the Dectalk, if somebody could ship it to me in Italy.
Anybody could help me with this?
Thanks
Andrea
Hello,
I have a clone PDP11, including an SMS QBUS board and a 8" drive.
Not sure if it's the same model as yours.
The controller runs MSCP for floppy with RX02 or IBM format , and for an
MFM hard disk like Seagate ST251.
Board code is SMS FWD0106.
I should have some manual and drivers for it somew
Hello,
all fine with Rigol or similar oscilloscopes, but there's a very important
technical specification that often is not considered, which really DOES the
difference between a cheap oscilloscope and a powerful one: waveforms per
second.
Suppose you are searching for a rare glitch, or that you ar
Hello,
where are you located?
If you are in EU, I'm interested.
Thanks
Andrea
Hello,
I'm in the pretty same condition, I have a Rainbow 100B without memory
expansion.
Not sure however, about the correct board number, which would fit the 100B.
What should I search for?
Thanks
Andrea
Well, it would be a very nice thing to put the hands on a copy of such
manual! :)
Given that I didn't find ANY information on Google about these boards,
except for the bare description in the PDP11 field guide, it would be very
nice to archive a copy on bitsavers too...
If you manage to find someth
Hello,
given recent posts about Unibus graphic systems, I'm coming back with a
request:
was anyone some documentation about board sets VT30-H and VTV30-J?
They should be graphic systems as well, the former Unibus, the latter Qbus.
Definitely I think they aren't "regular" DEC products, maybe they w
Hello,
I'm remembering of an old post on vcfed, somebody found in the dump a lot
of tapes and floppies related to DPS6.
IIRC Al Kossow contacted the man to have the dump of the disks...
Maybe he has something?
Andrea
Hello Adrian,
not sure if 8085 is supported, but try to analyze your dump with IDA
Disassembler.
It's really amazing in analyzing the code, and reconstruct automatically,
or with small effort, a readable trace of functions jumps, strings,
symbols, etc
Andrea
hello,
somewhere around I should have a floppy with disassembler for HP1660 series.
I suppose it is useless for 1630... or not?
Should I give a look to find it?
Andrea
Hello,
I'm interested in Rainbow and DecMate, specially if there are monitor and
keyboard.
Eventually also vax2000 parts, for possible repairs.
Thanks
Andrea
Hello,
we are discussing on separate thread about doing an universal interface for
PDP11.
I'm taking all the relevant documentation about Unibus and Qbus busses,
aiming to check the possibility of doing a board compatible, with some
adjustments, with both worlds.
I started to read the 1979 specific
Hello,
surely the old transceivers are the most compatible solution, however you
still need to convert the voltages back and forth...
Plus the solution is not the cheaper, and a little uncomfortable too, as
you need to find these old chips, hoping not to buy fake chinese duplicates
(it happened to
Hello Dave,
exactly!
But in place of a plain FPGA, nowadays I would choose a FPGA-ARM board,
for example
the ZedBoard MicroZed or the Myirtech Z-turn, both of them have a Zynq
onboard,
and they can run linux for the software side and programmable logic for
the interface side.
Very nice and fle
Hello Dave,
exactly!
But in place of a plain FPGA, nowadays I would choose a FPGA-ARM board,
for example
the ZedBoard MicroZed or the Myirtech Z-turn, both of them have a Zynq
onboard,
and they can run linux for the software side and programmable logic for
the interface side.
Very nice and fle
Hello,
I read several posts about Unibus disk interfaces and emulation.
One of my retrocomputing dream is to design an Unibus universal board,
probably based on FPGA because of precise timing requirements,
to emulate one or more disk/tape interfaces, and possibly something more.
The real storage c
Hello Rob,
I'm quite sure that the tantalum explosion has nothing to do with the
spin-up failure.
Indeed the RD53 (Micropolis) is infamous for a problem in the head
positioning shock absorber.
The head positioning system is based on a voicecoil inserted in the
magnetic field; the angle covered by t
Hello,
The same cabinet has a TK50 and I foolishly put a cartridge into it and
now it won't come out. It is called being 'stuck'. How do proceed to
get this TK50 cartridge out?
Error 'stuck' means that the tape has been "glued" to the head because of the
effect
of the tape binder being conv
Hello Rob,
I think I found a link:
http://vaxhaven.com/images/a/a7/EK-PC380-PS-003.pdf
Andrea
Hello Rob,
I don't think the leader can be repaired, as the used polymer doesn't
react well with glues, simply out will not be robust enough.
But if you have some patience and a sharp knife, topi can cut out new
leaders from black plastic layers, I used old X ray films of the bones.
I did it fo
Hello,
since the messages in May about the MS Windows 1.0 version for DEC Rainbow,
I did some research to see if a version is effectively available.
It seems that copies of this software are really difficult to find, but
a complete copy
was available on the latrobe ftp DEC Rainbow archive... whi
Hello Andreas,
nice to see you here from time to time.
I too have two TSZ07, but both had problems with the PSU after some time
of good working condition.
The problem was always related, as indirect cause, to bad electrolytic
capacitors, however the effect was always bad.
The first one in the
Hello Paul,
I have a Pro380, including box, PSU, motherboard, RX50 interface and RX50.
Unfortunately no other interface, so any missing part could be
interesting, specially HD / graphics / network.
Please let me know if you find something.
I tried to forward the sent emails from two different e
Hello Paul,
hope you are fine now.
I'm interested too to Pro380 boards, because I have a machine with
almost no expansion.
I'm trying to contact you since weeks, sent some emails but never
received an acknowledgement.
Maybe there are problems with spam-killers?
Please check your email and let
Hello Adrian,
if the head positioning motor works, but the drive simply doesn't read
the data,
maybe the problem is in some track misalignment or bad head signal
amplification / A/D conversion.
Don't know about these drives, but if the interface is pretty standard,
you could try the correct ope
Hello Mark,
when you are ready with your machine up and running,
you could try to use on a real Nova 3 the tool I wrote to raw read/write
disks and tapes through the serial port.
You just need a PC (linux preferred) and Python installed (plus serial
port module).
Then you should be able to dum
Hello,
I would need some clarification about the Plastibands, as I will have to find a
suitable replacement for the belt,
as ALL my cartridges need a replacement, after removing the old one without
causing the infamous blank-spot.
Al, please could you clarify which size / brand of (Baumgarten)
Hello,
I'm very interested on TU58, as I have a lot of tapes that I need to dump,
plus I would create some new (console at start) for my vax 730.
What I'm trying to do: use a drive mechanism connected with to modern mixed
signal microcontroller with USB port.
The device will be able to control the
Hello,
I'm a modest collector of DEC and PDP11 stuff, I always thank who wrote the
PDP11 field guide with the almost complete list of all the existing
boards...
Now comes the idea: could be useful having a website where the field guide
assume a graphical aspect, including pictures of the parts, des
Hello,
I have two TSZ07 here.
As they were sold as "for parts" obviously they both needed some repair.
One of the two had severe mechanical problems.
One motor had a loose unglued magnet inside, so there was a motor fault
error, and the motor couldn't rotate freely,
making a rattle noise inside
Hello Henk,
thanks for the link.
It talk about two boards (one hex and one quad). In effect mine are hex
and quad.
But the hex board has three IDC connectors, while the quad only two.
My suspect is that the third connector could go to some other module.
Do you have the VT30-H system too?
Could w
Hello,
I just acquired two DEC modules, M8295 and M7114.
These appear to be a video system for unibus, named VT30-H.
I don't find any info about these boards...
There's some documentation around?
Is the system complete or some other card is required?
Thanks
Andrea
So if all LEDs remain on, that most likely means the CPU is not able to execute
instructions at all.
It might mean a busted CPU, busted ROM or CPU bus, or missing power or clock.
Yes,
that's exactly my feeling... so a schematic would be very good to try to
diagnose an evident problem as mi
So if all LEDs remain on, that most likely means the CPU is not able to execute
instructions at all.
It might mean a busted CPU, busted ROM or CPU bus, or missing power or clock.
Yes,
that's exactly my feeling... so a schematic would be very good to try to
diagnose an evident problem as mi
Hello,
I recently took a DEC Rainbow PC100-A.
It has been a huge house for a lot of spiders, who deposited eggs and
dead insects all around.
After full disassembling, cleaning and reassembling, I'm ready to try it!
PSU seems to work well, power goes on with almost precise voltages, then
all the
Hello,
well, if you see square waves, probably the read path analog circuit
could auto-oscillate.
This could be because of poorly filtered supply (bad electrolytic
capacitors),
or possibly some component in the feedback that's not soldered well.
I should have a schematic around, I could give a
Hello,
I have some unibus machines that always need some way to interface to
modern disks.
I always dream to make an universal board that could act as disk and/or
tape interface to a modern medium (scsi or cf/sd card), but also ram,
network, I/O, whatever...
It would be very nice to design a system
Hello,
I'm curious to know if you managed to find some hard sectored floppies
to be used with your DG machine...
When you wanna have some fun to try, I could send you the current
version of the tool to transfer data between DG nova and PC.
Unfortunately I have no bootable media yet, but maybe an
Hello,
I'm almost sure that the DG dual 8" uses hard-sectored floppies with 32
sectors (33 holes).
The internal logic will generate sync signals for 8 sectors starting
from the 32 on the floppy.
So industry standard hard-sectored floppies should be fine.
You need to use formatted disks, DG supp
Hello,
you have a very nice lot of DG stuff, indeed!
I have a Nova 3 sitting on the garage, waiting for proper repair.
However it's missing all the front panel switch levers,
so I would need to rebuild them, not having had the luck of finding some at
reasonable price.
I have some picture of the or
Hello Paul,
I sent you an email, not sure if you received it, maybe antispam?
Thanks
Andrea
Hello Adrian,
how are you?
Maybe you still have the SDI disks aside for me?
Any time to ship them to me?
Thanks in advance!
Andrea
Hello Paul,
good luck for your surgery! I hope there's nothing too bad.
As for the "business", I sent you more emails in the last months,
unfortunately no answer at all...
maybe I went direct to spam? :(
Anyway, when you are back good, please let me know something.
Thanks
Andrea
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