Folks,
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.
Some of these designs were used on several manuals, but I'd like to
know if you know of any other designs that follow this pattern that I
could add to the collection? The VT102 User Guide has different
colours, so it looks out of place. A copy of the LA34 User Guide is
winging its way to me as we speak.
For an infinite number of bonus points, does anyone have any clue who
might have designed these?
Paul
Looking for an Acorn A3010 or A4000 + KB/Mouse, happy to repair it.
Also Sinclair +3 with some disks
Also BBC Micro
Also Amstrad CPC 6128 color. Could forgo monitor and build my own PSU.
- Ethan
Hello All,
I have a PDP 11/05 that I’ve been restoring slowly over the last few years. I’m to the point now where I’d like to get a paper tape reader attached to it. The only reader I can find in my junk is a Bower Associates BAI Data Products model 1230 punch. I’ve put a picture of it here for the curious:
https://imgur.com/a/xJ2hyTS
Imgur
imgur.com
I can’t find any documentation online about this machine. I’m wondering if anyone else has any ideas, or might know anything about this. It’s going to need some TLC to bring it to life, and some documentation would certainly be nice.
This particular unit was used by the Atmospheric Environment Service, Department of the Environment of Canada (according to a label on the back). It looks to be complete, except the punch bin is missing (not a big deal).
Anyway, I thought I’d throw it out there in case anyone happens to know anything about this, before I tear in to it.
Thanks!!
Ian
I had a dream ; that someone makes a small telnet to chatgpt gateway (using azure chatgpt API possibly ?) So that we could telnet our retro devices to the hype of the year, and get chtgpt answers in our TRS80, PDP and such.
Hello, I recently got my IBM 029 keypunch working, and am expanding the
search for a punched card reader.
Ideally RS-232, but unknown protocol or parallel is fine also. Repair
required is also fine :).
Thanks for any help!
-Eric
Hello,
I could use some help making sense of the VAXstation ROM images.
A set is provided here: https://www.9track.net/roms/
The two .bin files are each one halfword of a 16-bit wide ROM for the
68000 display processor. I checked it, and it's fine.
My problem is with the Bit Blit Accelator. The board has four Am2901
bitslice processors to make up a 16-bit custom blitter. The information
I have is that the microcode is 57 bits wide and there should be 1024
words. However, this is not a great match for the rest of the ROM
images.
Some of the BBA ROMs seem to be bit masks, presumably useful for
rendering graphics. But none of them seem to match what I'd expect to
see for a 57x1024 microcode.
Here are the sizes, in bits, of the ROMs:
Bit Blit Accelerator (BBA)
23-066K3.jed 2048
23-067K3.jed 2048
23-068K3.jed 2048
23-069K3.jed 2048
23-076F4.e32 16384
23-077F4.e65 16384
23-077J5.jed 2048
23-078J5.jed 2048
23-354A1.e33 256
23-355A1.e66 256
23-356A1.e77 256
23-357A1.e85 256
Display Processor Module (DPM)
23-020L1.jed 3553
23-021L1.jed 3553
23-022L1.jed 3553
23-023L1.jed 3553
23-024L1.jed 3553
23-025L1.jed 3553
23-288E4.bin 65536 68000 code in these two.
23-289E4.bin 65536
Hello, I am looking for 3/16ths inch ink ribbon as used on the IBM 029
keypunch.
I have one lightly damaged ribbon that is entirely dry. I was told by a
typewriter restorationist that ribbon re-inking with nylon never works.
Has anyone had much success cleaning and rewetting ink ribbons? The WD40
trick on the internet seems like it would gunk up the punch mechanism.
Thanks for any information yall can provide,
-Eric
Some thoughts on this day of working on MFM drives:
1) MFM drives are just going bad. They were always kind of meh in terms
of reliability, but I think even since 2019 (the last time I checked
these drives) things have gotten worse. Drives which were readable and
good then are now either shot or throwing errors and they have had an
easy 3+ years in my upstairs room.
2) There are at least two RQDX3 ROM sets. The earlier one does not
support the RX33 floppy and doesn't give any info during formatting. The
later version (Version 4) does support the RX33 and is a lot nicer.
3) Seagate drives seem to be pretty good, especially the 20mb ones. They
have no problems, work well, and are pretty right-sized for an RT11 system.
4) RD53 drives are weird. Their main failure is the drive head
positioner just gets stuck and needs to be worked loose. Unfortunately
that requires removing the lid. Fortunately there is a good filter in
the drive along with an air handler that runs air from inside the drive
body through the filter, then into the spindle where it is blown over
the heads. Result is a pretty clean drive on the inside and so far
opening the lid doesn't seem to be a recipe for instant destruction. Go
figure.
I may try an RD53 in one of my Pro/380's. It's about time I loaded up
the final version of P/OS, as I can use the Gotek floppy to load
everything instead of screwing with the RX50's. Or can I do that and
switch disks on the fly with a single Gotek... Hm.
5) For anything bigger, it's time to retire the MFM drives. Unlike
RL02's these things just were not that reliable when new and at this
point are kind of falling apart. I have not had any trouble with the
ESDI disks, but it might just be a matter of time. Perhaps I should look
into duplexing my 330mb CDC drive in the 11/84....
CZ
After more than three years, U of Iowa's PDP-8 project active again
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
I have the following Q-BUS boards available.
M7168 VCB02, QDSS Q 4-plane colour bitmap module
M7169 VCB02, QDSS Q 4-plane video controller module
M7608 MS630 RAM for KA630
M7608 MS630 RAM for KA630
M7606 KA630 Microvax II CPU
M7620 KA650 Q MicroVAX III CPU
M7165 Qbus SDI disk adapter
I also have a Smoke Signal Broadcasting, dual 8" floppy set and a SS50 bus
controller for the same. All are available for pick-up in Queen Creek, AZ,
USA.
If there's no interest, all will go to recycling.
Decided to spend some time working on my 11/73 with MFM drives.
Currently it has one of my RQDX3 boards (I have 3, 1 in attic), a 40mb
ST412 drive (the half height Seagate whatever) which works fine. No
issues there.
I'm trying to format an RD54 compatible drive and am running into major
issues. First, my two RWDX3's have different ROM dates, the old one is
1986 and the new one is 1990. This is important because I can't boot
RX33 disk images with my GoTek using the old card but I can using the
new one.
Question: I'm guessing the old ROMs only supported RX50 disks? Or is it
a secret jumper setting.
Anyway I do have both RX33 and RX50 versions of XXDP so not a big issue.
On to formatting.
The old controller (which I used for the 40mb Seagate) had pins 2-3
jumpered on W23. With that the RD54 was able to autoformat but then
would crash xxdp as soon as the initial format was done. Odd. So I used
the new controller with 1-2 and 3-4 jumpered. Same problem. Then I tried
having 1-2 jumpered and did a manual format (not autoformat, select
RD54, etc)
I noticed that on the old board it would ask me for the date when doing
this kind of format, on the new board it would just ask me for the
serial number. Odd.
Question: Is the ZRQCH0.BIN file calling different routines in the RQDX3
ROM?
Anyway after this the drive would format but then do endless seek errors
on the "read" portion of the disk check. Two drives did this, so it's
probably not the drives. Odd. Putting the drives on the Dave Gesswin MFM
reader showed all cylinders could be read.
Question: Can Dave G's board be used to low level format an RD54? Can it
test physical disk for errors (wasn't sure)
Now the drives only format for a minute or two before throwing errors.
Looks like something is very confused on XXDP. Not going to try any
other disks until I figure this out.
Thoughts? Different sites say different things about the RQDX3 jumpers,
some say to jumper 2-3 to allow more than 7 heads, some say to jumper
pins 1-2 and some say jumper pins 1-2 on "early ROM" and 1-2 3-4 on
"later ROM".
This is a serious pain, but just what settings should be done to allow
low level formatting, and did my previous attempts to low level wedge
these disks from the RQDX3 point of view? Can I do a low level wipe with
Dave Gesswin's board/software?
Thanks!
Chris
The ST512 was a thin-film head version of the ST506, per Seagate :
"This increased capacity is accomplished by using the inner portion of the disc surface that was previously unused and by increasing the disc track density from 255 tracks per inch to 270 tracks per inch To reliably use the inner portion of the disc. The ST512 uses a new type of read/write head - a "thin film" head."
It was dropped in 1981 due to the lack of a reliable supply of heads and replaced by the ST412.
-----Original Message-----
From: Tony Duell [mailto:ard.p850ug1@gmail.com]
Sent: Friday, February 03, 2023 9:27 AM
To: Alexandre Souza
Cc: General Discussion: On-Topic and Off-Topic Posts
Subject: [cctalk] Re: Nuking an MFM drive with a magnet, format/servo gone?
On Fri, Feb 3, 2023 at 5:21 PM Alexandre Souza <alexandre.tabajara(a)gmail.com> wrote:
>
> I thoug the right one was st512...can you enlighten me on this subject Tony?
I've never heard it called that.
It's often called 'ST506' but that drive had a few differences from the later ones. it didn't support buffered seeks AFAIK. The ST412 did and was the most common of a family of 3 similar drives (ST406, ST412,
ST419) so it tends to be used as the de-facto name of the interface.
-tony
Decided to spend some time working on my 11/73 with MFM drives.
Currently it has one of my RQDX3 boards (I have 3, 1 in attic), a 40mb
ST412 drive (the half height Seagate whatever) which works fine. No
issues there.
I'm trying to format an RD54 compatible drive and am running into major
issues. First, my two RWDX3's have different ROM dates, the old one is
1986 and the new one is 1990. This is important because I can't boot
RX33 disk images with my GoTek using the old card but I can using the
new one.
Question: I'm guessing the old ROMs only supported RX50 disks? Or is it
a secret jumper setting.
Anyway I do have both RX33 and RX50 versions of XXDP so not a big issue.
On to formatting.
The old controller (which I used for the 40mb Seagate) had pins 2-3
jumpered on W23. With that the RD54 was able to autoformat but then
would crash xxdp as soon as the initial format was done. Odd. So I used
the new controller with 1-2 and 3-4 jumpered. Same problem. Then I tried
having 1-2 jumpered and did a manual format (not autoformat, select
RD54, etc)
I noticed that on the old board it would ask me for the date when doing
this kind of format, on the new board it would just ask me for the
serial number. Odd.
Question: Is the ZRQCH0.BIN file calling different routines in the RQDX3
ROM?
Anyway after this the drive would format but then do endless seek errors
on the "read" portion of the disk check. Two drives did this, so it's
probably not the drives. Odd. Putting the drives on the Dave Gesswin MFM
reader showed all cylinders could be read.
Question: Can Dave G's board be used to low level format an RD54? Can it
test physical disk for errors (wasn't sure)
Now the drives only format for a minute or two before throwing errors.
Looks like something is very confused on XXDP. Not going to try any
other disks until I figure this out.
Thoughts? Different sites say different things about the RQDX3 jumpers,
some say to jumper 2-3 to allow more than 7 heads, some say to jumper
pins 1-2 and some say jumper pins 1-2 on "early ROM" and 1-2 3-4 on
"later ROM".
This is a serious pain, but just what settings should be done to allow
low level formatting, and did my previous attempts to low level wedge
these disks from the RQDX3 point of view? Can I do a low level wipe with
Dave Gesswin's board/software?
Thanks!
Chris
On 2023-02-02 04:38, David Brownlee wrote:
> That reminds me (looks at 43.5T of zfs pool that has not had a scrub
> since 2021).
>
> It can be nice to have a filesystem which handles redundancy and also
> the option to occasionally read all the data, check end to end
> checksums (in the unlikely case a device returns a successful read
> with bad data), and fixup everything. Does not eliminate the need for
> remote copies, but gives a little extra confidence that the master
> copy is still what it should be :)
So, what else do you guys use, to make sure your data is safe for the
years to come?
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
One website has an archive of the first Homebrew Computer Club newsletters. The newsletter is associated with the Homebrew club that kicked off the personal computer revolution
https://arkive.net/gallery/homebrew-computer-club
Regards,
Tarek Hoteit
Museum Staff Helps Exonerate David Veney
January 19, 2023, Hunt Valley, MD — Staff members of the System Source Computer Museum recently completed a project that helped exonerate David Veney, wrongly convicted of rape in 1997. In 2005, after Mr. Veney sought a new trial, the state found irregularities in the prosecution, released Mr. Veney from prison, and declined to re-prosecute.
Maryland is one of 35 states that provides compensation for wrongly incarcerated people. But quirks in the law kept the law from applying in Mr. Veney’s case. In 2021, the Maryland law was amended, making Mr. Veney eligible for partial compensation for the nearly nine years he spent in prison. Still, Mr. Veney had not been exonerated..
In June 2022, the Computer Museum at System Source in Hunt Valley, MD, was contacted by Patrick Gilbert, Senior Assistant States Attorney and Chief of the Prosecution Integrity Unit, who asked “Can you read data from a 5.25” Floppy Disk?” Bob Roswell, curator of the museum, quickly replied “Of course!”
It wasn’t quite that simple. In theory, the diskette contained the court stenographic records from the 1992 rape trial of Grant Jones. The transcript was thought to contain evidence that would exonerate both Mr. Jones and Mr. Veney, but the printed transcripts from 1992 had been lost. Unfortunately, the diskette was neither IBM- nor Apple-compatible. It had been written on a DEC PDP-11 minicomputer using the RSX-11 Operating System. Although the museum has a PDP-11 in its collection, it had not yet been restored and could not be started. Brendan Becker, who runs the BLOOP museum inside the Computer Museum, jumped on the problem.
Brendan set up a “Greaseweazle,” a device that reads the magnetic flux transitions on the floppy disk without regard to operating systems, disk formats, or errors. The process returned a file containing long binary strings of ones and zeros. Brendan was able to decode the file structure and found that disk (despite some unreadable parts) contained the raw keystrokes that the court stenographer had recorded in the 1992 rape case using a Stenograph machine from the era. An operator of a Stenograph machine uses chords to rapidly encode conversation by creating keystrokes to represent words, syllables, and phrases. While there is some standardization, each stenographer has his/her own “theory,” which results in individual styles for different stenographers.
Luckily, Patrick Gilbert was able to obtain the services of the stenographer from the original trial (now retired). Together, they were able to substantially reconstruct the transcript from the 1992 trial, using the data provided by Brendan. The recovered transcript showed weird similarities to Mr. Veney’s case.
On March 4, 1992, Alice Arroyo claimed to have been raped while walking home from volunteering at homeless shelter. In her account, the assailant grabbed her shirt, ripped it open, and scratched her chest with his nails in a long, vertical raking motion. Ms. Arroyo provided police with a detailed description of her assailant including the jacket he was wearing. The following day Grant Jones walked into the Salisbury Police Department (in Wicomico County, MD) to report that his wallet had gone missing from the homeless shelter. Mr. Jones matched the description of the assailant, was arrested, and was convicted of assault with intent to rape.
On September 24, 1996, Salisbury Police responded to a complaint at the home of Alice Arroyo, who stated that she had been raped. Again, she provided a detailed description of the assailant and described suffering scratches on her chest in a long vertical raking motion. On October 3, 1996, David Veney, a former neighbor, was charged with rape. He was 20 years old at the time.
Mr. Veney’s first trial in April 1997 ended in a mistrial. The hung jury consisted of four jurors voting to convict and eight declaring him innocent.
In September 1997, Mr Veney was retried and found guilty of various charges, including burglary, assault, battery, and rape. He was sentenced to 25 years for rape and concurrent sentences for the other offenses.
In 2005, Mr. Veney sought a new trial on the basis of ineffective representation. (That lawyer was later disbarred.) When the State reviewed the case, substantial doubts about Mr. Veney’s guilt arose, including the eerie similarity in Ms. Arroyo’s testimony in the two cases. Mr. Veney was released from prison, and the State declined to re-prosecute.
The reconstructed transcript of Mr. Jones’ 1992 trial proved vital in establishing Mr. Veney’s innocence. On January 13, 2023, Judge Teresa Garland awarded Mr Veney approximately $730,000, along with medical, housing, and educational benefits.
The staff of the Computer Museum at System Source is proud to have played a small part in Mr. Veney’s exoneration. Bob Roswell, Curator, later learned that the state had contacted numerous other technology firms, who were unable to render assistance, before asking the Museum for assistance.
The Amendment to Maryland Law Regarding Compensation for Wrongful Convictions:
https://mgaleg.maryland.gov/2021rs/Chapters_noln/CH_76_sb0014t.pdf
Greaseweazle:
https://decromancer.ca/greaseweazle/
Stenography Theories:
https://www.artofchording.com/introduction/theories-and-dictionaries.html
The System Source Computer Museum:
Bob Roswell
https://museum.syssrc.com/
I had some idea of trying to get money for an HP 41-CX a while back,
but on balance I think it's best to just go to someone who might be
interested in fixing it up and valuing it for what it is.
So - FTGH, just the cost of shipping (photo link below still valid)
David
On Sun, 19 Apr 2020 at 17:55, David Brownlee <abs(a)absd.org> wrote:
>
> I've come into possession of an HP 41-CX calculator - unfortunately it
> appears to have had batteries left in it which have left corrosion on
> the internal contacts.
>
> (some pics: https://photos.app.goo.gl/48bE7WJZP8R4PF9a9 )
>
> My classic hardware tendencies tend to run more towards the "can run
> *nix" end, and while I could just clean it up and throw it on eBay I
> wondered if anyone here has a 41C shaped soft spot and would be
> interested? (happy to trade/part trade for something they already have
> for which they are less fond if that works :)
>
> David
Some of the floppies I’m recovering data look to be either a multi-part ZIP file, or something. Was this a separate product from PKZIP? I’m not sure if I have a copy of PKZIP in the stuff I’ve recovered thus far. I’ve not pulled them into DOSBOX to try and restore them, so far I’ve just tried to use Stuffit-Expander. Part of the problem is every file has the same name, just on different floppies.
Zane
I find myself wondering, how well does CD-R and DVD-R media that hasn’t been used age? I have quite a bit of unused Verbatim DataLifePlus, as well as some other media that’s unused.
For the most part, I don’t need it, but I can see a couple reasons I might want to burn some in the future, mainly to exchange data with older systems.
Zane
Over at the CoCo Mailing List, there's a archeological discussion about
the DLOAD BASIC command in older versions of the Color Computer BASIC.
It uses the serial port (and no doubt was designed for computer sharing
in classrooms or similar), but the questions are around how it was
designed and what inspiration is drew from.
I infer MS wrote the code, and the protocol includes:
P.ACK - Acknowledge - C8 hex.
P.ABRT - Abort - BC hex.
P.BLKR - Block request - 97 hex.
P.FILR - File request - 8A hex.
P.NAK - Negative Acknowledge - DE hex.
Does that look like any protocol anyone has seen before?
Jim
why does this happen? how do I "reset" a floppy drive (in windows) so that it tells me what's on the current disk, not what was on the previous disk that's been removed.
These items have all been claimed.
David
> On Jan 31, 2023, at 12:57 PM, grif615(a)mindspring.com wrote:
>
> Does the post office still have a book rate?
>
> On Jan 31, 2023 10:12, David Barto via cctalk <cctalk(a)classiccmp.org> wrote:
> This is all on paper and weighs a fair bit.
> Located in San Diego area, so pickup would be best.
> I’m willing to ship it for 50% of the shipping cost.
>
> All classic computer related:
>
> UCSD Pascal pSystem listing from UCSD Pascal II.0 along with notes about what BIOS failures look like.
> Listing of a pascal_interpreter, written in Pascal (of course)
>
> Tech Notes and Books:
>
> Tech Notes:
> Booting the CP/M Adaptable System on the IMS8000
> SofTech MicroSystems Errata sheet for the FORTRAN Manual
> UCSD Pascal System Synchronous Input/Output Subsystem Implementation Guide (II.1, Preliminary) Date 10 April 79
> SofTech MicroSystems Marketing Department memo on Version IV compatiblity with Preceding Versions
> SofTech MicroSystems Adaptable System Tech Note (TN #2)
>
> Books:
> UCSD Pascal Version I.5 September 1978
> UCSD Pascal Version II.0 March 1979
> SofTech MicroSystems Micro News Vol I, No. 3 May 1980
> SofTech MicroSystems UCSD Pascal II.0 Users Manual Feb 1980
> SofTech MicroSystems UCSD Fortran User Reference Manual May 1980
> Practical Pascal Programs By Greg Davidson
>
> David
>
>
>
This is all on paper and weighs a fair bit.
Located in San Diego area, so pickup would be best.
I’m willing to ship it for 50% of the shipping cost.
All classic computer related:
UCSD Pascal pSystem listing from UCSD Pascal II.0 along with notes about what BIOS failures look like.
Listing of a pascal_interpreter, written in Pascal (of course)
Tech Notes and Books:
Tech Notes:
Booting the CP/M Adaptable System on the IMS8000
SofTech MicroSystems Errata sheet for the FORTRAN Manual
UCSD Pascal System Synchronous Input/Output Subsystem Implementation Guide (II.1, Preliminary) Date 10 April 79
SofTech MicroSystems Marketing Department memo on Version IV compatiblity with Preceding Versions
SofTech MicroSystems Adaptable System Tech Note (TN #2)
Books:
UCSD Pascal Version I.5 September 1978
UCSD Pascal Version II.0 March 1979
SofTech MicroSystems Micro News Vol I, No. 3 May 1980
SofTech MicroSystems UCSD Pascal II.0 Users Manual Feb 1980
SofTech MicroSystems UCSD Fortran User Reference Manual May 1980
Practical Pascal Programs By Greg Davidson
David
Originally as I understand it the mouse as a product of Xerox was intended not so much for general use but to aid youngins and disabled people with their usage. And despite the never-mousers, predominantly linux fanatics, it's an indispensable tool for nearly everyone. There was a stint where I favored trackballs. But it's a toss up as to which is more natural and faster. Each may excel in cwrtain applications.
Then there's the touch screen (and touch pad). I find touch pads superior, make that way superior to that horrific track point used on old Thinkpads. But again that'a me. Touch screens, my hatred for them grows almost daily. They have their place. And for portable devices they're largely the only game in town. But I often wish I at least had the option of a mouse or something close.
Is this an example of where older tech beats the new tech? Or do aspects of the newer tech just await refinement?
I have 2 of these that are in need of a new home. These are quite large 4 racks each. Although the 11/60 is only a double rack by itself.
Offers. Located In Kent. WA.
- Jerry253-569-6041
Hi,
Can someone recommend a place where I can buy replacement tension band for
QIC(-150) tapes? I known about the boiling trick, sadly I don't have any
original bands to boil 😁.
Thanks.
Regards,
BogDan.
P.s. I found on Amazon a few alternatives, but they are quite thick (1.5mm)
while the original ones are much thiner.
Hi,
Can someone recommend a place where I can buy tension bands for QIC(-150)
tapes? I known about the boiling trick, sadly I don't have any original
bands to boil 😁.
Thanks.
Regards,
BogDan.
P.s. I found on Amazon a few alternatives, but they are quite thick (1.5mm)
while the original ones are much thiner.
I’m looking at some 3.5” floppies from about 1995, so probably about the time I got my first Mac.
Am I correct that System 7 used A:\RESOURCE.FRK\DESKTOP as the Resource Fork data? MacOS 12.5 doesn’t appear to use it. :-)
A bunch of the floppies I’m looking at have this, including ones that appear to be PC Backups.
Zane
Message: 4
Date: Sat, 28 Jan 2023 21:54:50 +0000 (UTC)
From: Jerry Wright <g-wright(a)att.net>
Subject: [cctalk] DEC PDP 11/60's in need of a new home.
To: "cctalk(a)classiccmp.org" <cctalk(a)classiccmp.org>
Message-ID: <1945749291.492113.1674942890123(a)mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8
I have 2 of these that are in need of a new home. These are quite large 4 racks each. Although the 11/60 is only a double rack by itself.
Offers. Located In Kent. WA.
- Jerry253-569-6041
-These are most likely sold...
I do have some Data Generals, and HP 1000's next up.
Jerry
253-569-6041
It appears that the cctalk archives stopped updating in July 2022. See the
link below:
https://classiccmp.org/pipermail/cctalk/
Could the new list admin please re-enable the archive feature of the
mailing list and if possible fill in the missing months since July 2022.
Thanks and best regards
Tom
I obtained a bunch of MB (1?) cards from a fellow list member. Mostly Intel, 1 Matrox video card. Didn'y see a floppy controller anywhere, but I'll have to look closer. I have an Intel 286/20 chassis (the 20 doesn't mean mhz). Got to get me a keyboard and I'll be all set, right? O how I wish. There's an MDS keyboard on ebay, kind of pricey. Have to wonder where I'd stick the plug. No ribald suggestions please.
So apparently my future has taken a turn for the very grim. As I'll be writing device drivers from this point until my death. Yep. It's all rawhide and buffalo chips from here on out. Maybe sum yu westerners can give me a hand. Fred, Chuck, Sellam. You're all westerners and cowboys apparently. Just rustle up some docs and software for me.
I finally got around to replace the dead TO-3 power transistors in my
VR-14. They are mounted on the power supply regulator heat sink using TO-3
sockets made by AUGAT. Unfortunately one of the sockets has been broken by
somebody in the past by over-tightening the transistor mounting screws.
This may have been the root cause of the power supply failure as one
transistor was doing all the work with the second transistor's collector
lead having poor or no connection. There are two NPN transistors in
parallel to double the power which is not a very good design anyway.
I am trying to find the original Augat sockets.
Here are some links to photos showing a closeup of the socket and the
threaded insert with the originally crimped collector tab which broke out
of the bakelite socket:
https://drive.google.com/file/d/1MXclwHLDmoz_P2ub7tPc9oqSgrDbnTzR/view?usp=…,
https://drive.google.com/file/d/1XJ7DpGA5Zx0ZSqDVL_gdBSWYuKdFHLlR/view?usp=…
I would be grateful for any help trying to source these AUGAT made TO-3
sockets. I had no luck finding stock of these with Google and Ebay.
Thanks and best regards
Tom
Hi,
PLEASE TRIM THE DARN POST BEFORE REPLYING!
For example, Bill's interesting post about needing space was 75 lines long
(#1)...
The first reply included the ENTIRE MESSAGE.
The second, from another very long time participant, was TWO !@#$%^& LINES
OF NEW CONTENT, with *TWO COPIES OF THE ORIGINAL POST* (about 145 lines).
I don't want to single out just that post ... I haven't counted, but I'd
bet that the vast majority of posts include the entire OP, and replies!
Some other post had three copies in today's digest.
The basic guideline is to quote *just enough* for the reader to understand
what you're referring to. (Whether you quote below or above is another
subject entirely :)
Please have consideration for *EVERY* reader of this list, our disk space,
and our network bandwidth!
thanks,
Stan
----
1. BTW, Bill, that line count includes the totally unnecessary (and never
believable) text:
"This email has been checked for viruses by Avast antivirus software.
www.avast.com"
Companies don't care about history. It does not affect the next
quarter's sales. I had serial number 1 of a Radio Shack shortwave
receiver and offered it to them.
I got a reply back, 'I'm sorry, we no longer support that model.'
cheers,
Nigel
C: wow I didn't even know the Shirt Shack monitored much less replied to customer inquiries via shortwave. I suppose that's 1 way to get patrons to buy your rigs.
I snipped this from an instant post on facebook, 26Jan2022 at 12:35pm
Eastern Standard Time.::
We just de-commissioned our HP3000 minicomputer in December 2022 and are
willing to give it away free to anyone willing to pick it up. Photos to
follow, but it is the whole system, with 2 green bar printers, manuals
et al.
Be sure you understand what this is. It is a 1970s era minicomputer that
is large and heavy. Sitting on our loading dock inside our building it
takes up maybe 10 feet of wall space. This is not a modern "mini
computer" like an Intel NUC or Mac Mini... this thing is a BEAST.
Priority given to whomever can pick it up first during business hours
(8:00am to 5:00pm). Located in Denver, Colorado near I-25 and Colorado Blvd.
I have a few scanned somewhere. I always kimd of liked Douglas Halls Microprocessors and Interfacing: Programming and Hardware for 80x86. It's a large format textbook. There is a 68000 version which I don't have. Curious what textbooks other can recommend.
As I said I scanned at least 2, maybe 3 some time ago. The Antonakos book seemed to stand out.
https://www.amazon.com/68000-Microprocessor-Hardware-Principles-Application…
I thought this was an excellent article on work at CHM on curating,
documenting, and making Apple Lisa software available - thank you Al. Would
be interesting to see other software collection objects curated in this way.
https://computerhistory.org/blog/apple-lisa-still-more-to-uncover/
Enjoy!
--
Lee Courtney
Philip Belben gave me a Philips P2000C luggable CP/M computer some
time back which had not been well-stored. It took a bit of work to get
it going
again. Here's what I did...
The basic desgn is a single-board computer with a Z80A, 64K RAM, 4K
ROM (bootstrap and a machine code monitor), floppy disk controller,
SASI interface and 3 serial port. One for an external printer, one for
communications [1] and one to provide a 19200 baud link to the other
main circuit board. This is an intellegent terminal with another Z80A,
32K RAM, video circuitry, keyboard interface and of course a serial
port
[1] Standards are wonderful, everybody should have one of their own...
This serial port is on a DB25 connectorr with the normal RS232 pinout,
but normal RS232 cables probably won't work. The reason is that
Philips decided to support synchronous operation too. So the serial
chp (Z80A-SIO) clocks come from pins 15 and 17 on the connector via
level shifters. The baud rate generator (one channel of a Z80A-CTC) is
level shifted and comes out on pin 24 of the connector. You therefore
need to strap 15-17-24 in the cable plug for normal asynchronous
operation.
Getting back to the machine, as well as the 2 main boards, there's a
switch-mode power supply, a Misubishi 9" green screen CRT monitor (Why
not Philips, they were certainly making such things at the time), a
pair of Teac FD55 floppy drives (of which more later) anf the'power
distribution PCB' to link them all toghether. Oh, and trivial things
like the keyboard cable and mains input wiirng.
I have the Philips service manual which contains schematcs for the 2
main boards but not the rest. I also have the Teac service manual for
the floppy drives.
Obvious faults on first inspection were that the mains on/off switch
didn't latch properly, there was a lot of corrosion, and the carrying
strap was missing. The last is important as to carry the machine you
put the keyboard over the front panel, then slot the strap end
fittings in place which also retain the keyboard.
I took the machine apart and found that the terminal PCB at the back
had suffered badly from poor storage. So had the disk drives, the
spindle bearings felt very rough. The aluminium chassis had surface
corrosion. Screws were very rusty (but standard M3 and M4 parts are
not hard to get). The rest didn't look too bad.
Time to sort some things out. I traced out the schematics for the
power supply, monitor and the power distibution stuff.
There were some RIFA 'smokebomb' capacitors on the PSU board which I
replaced before they did their antisocial act. Since the mains switch
was out of action I coupled a suicide lead to the power supply input
pins with a chocolate block and carefully powered it up with a light
bulb in series. The power supply worked first time.
Tried the monitor board, running it on the bench supply. This powered
up too, the high voltages came up but were low. As I didn't have the
deflection yoke connected this didn't worry me. So I put the monitor
chassis, PCB and CRT bak togther and connected it and the terminal PCB
to the units power supply.
Powered up, the screen was full of odd characters. It was clear the
terminal processor wasn't doing the right things. Some checks showed
the data lines on the RAMs were not looking right.Well, a couple were,
but not the rest. Cut out the old RAMs, most of the DIL packages fell
apart (!), fitted sockets and new 4116s. Corrected one open-circuit
PCB trace too. Powered up again ,it seemed to work.
Tried connecting the main board. It powered up and even gave the right
startup screen asking for a system disk. Of course no drives or
keyboard at this point, but it was a good sign.
Took the keyboard apart, took off all the keycaps and removed the
dregs of many cups of coffee. Put the keycaps back on.
The keyboard cable, right-angled 6 pin DIN plugs at each end, was a
mess. Insulation crumbling off, green corrosion of the wiring.
Fortunately the plugs are not moulded, so I could open them up, remove
the dead cable and rewire with a length of 6 core screened. It's not
coiled stretchy stuff like the original, but it's electrically fine.
Time to sort out the mains switch. I took it apart. An internal, tiny,
spring was so badly corroded that it fell apart when I touched it.
Other bits didn't look great either. My junk box disgorged an
electrically-suitable switch that was actually a spare for a TV set.
Only problems were that the pushrod to fit the button onto was 1/8"
square (the original one for the P2000C was 3mm) and the mounting was
very different. A file cured te first poblem. Fortunately the switch
mouting was a little plate screwed to the PSU mounting, so I removed
that and milled a block of aluminium to mount the replacement switch.
Soldered the mains harness wires to the new swtich.
While the chassis was apart I measured up and made some suitable end
fittings for the carrying strap. Oriiginals were plastic, I made
aluminium ones. Not too hard in that the tongue that goes into the
P2000C catch is 30mm wide by 2mm thick and amazingly a local-ish DIY
shed had 1m lengths of 2mm aluminium strip 30mm wide in stock. Cut
lengths of that, drilled and milled the hole to engage with the catch,
fitted a metal block to retain the keyboard and an eyebolt into that
to put the strap on.
Now to reasemble the chassis. Fitted the mains wirng, keyboard
connector, distribution PCB, PSU and monitor. Plugged in the terminal
PCB and connected the keyboard. Powered up then reset while holding
<esc> down. This runs a simple self-test of the terminal board. It
failed with a memory problem. I found another bad conneciton, this
time a through-board VIA. Soldered a bit of wire through that and the
terminal board then passed the self-test. I temporarily fitted it to
the chassis so as not to have too many bits hanging on wires. Put the
main PCB on top of the chassis, connected the power, reset, and serial
connectors. Powered up, got the 'system disk' prompt. Pressed <esc>
then and was in the machine code monitor. I could display/change
memory, etc. It was essentially working.
OK, now for the drives. These are Teac FD55A, single sided 40 cylnder.
I took them apart one at a time. Not just to the units in the service
manuak, I also took the head-load unit apart (tiny torsion springs),
the top front chasss (even smaller E-clips), the stepper motor (the
front bearing could not be removed without possibly damaging thngs,
but the rear came off easily with a puller so I fitted a new ball race
here) and the spindle motor (again, new ball races fitted).
Got the drives back togther. They ran nicely on the exerciser. Much
more smooth than they were when I took them out. Connected them to the
Microtest alignment unit and did the head alignment. One oddity was
that both spindle motors were slightly slow (about 295 rpm, not 300)
but a tweak of the pot on the motor PCB cured that
Also set up the disk read VCO on the mainboard as described in the
service manual. It was a little off, I am sure it would have worked,
but I re-set it anyway.
Cabled up drive 0. Powered up and put a 40 cyclnder boot disk in. It
booted. DIR worked too. As did running a program off the disk.
Unplugged things and removed the terminal PCB. Put the 2 drives in
place, fitted their mountings and the chassis top rail. Fitted the
main PCB and terminal PCB to the rear chassis plate. cabled everything
up.
Tried the machine again. It booted. I could format a blank disk in the
second drive and copy the CP/M master too it. The copy then booted
fine.
All that remained was to fit the rear plastic panel and top cover.
Stored the boot disk copy and the keyboard cable in the cubbyhole on
the front panel and put the keyboard on. Clipped on the carrying
strap.
It's not quite over...
I am pretty sure my strap end fittings are strong enough. Not so sure
about the strap itself which is one that came with a sports bag. I
may try to get something stronger.
I was given a few floppies with the machne. The only one it will read
is the 40 cylinder boot disk. Philips, you see made 3 versions of the
machine. One had a pair of 40 cylinder single-head drives (160K each).
The second had a pair of 80 cylinder double head drivs (640K each).
The last had a single 80 cylinder double head drive and apparently you
could fit a 10MByte wnchester internally. I know nothing about that
really..
Confusingly, the manuals call the 160K drive 'single density' and the
640K one 'double densiry' for all both use MFM encoding. But I
digress.
My guess is that at least some of the unreadable floppies are 80
cylinder. It would be worth linking up an external drive to see. Time
to hunt in the junk box again.
Then there's the SASI port. One manual mentioned a hard disk unit to
connect there, a 'Xebec board and 1 or 2 10M drives'. My guess is that
the former is an S1410, the latter a pair of Shugart ST412s or
similar. But it seems crazy to me to try to track down said parts --
the Xebec board has serveral custom ASICs on it, hard drives can
headcrash. Or even worst to use a Xebec controller with a drive
emulator -- why convert bytes to a curious serial stream on the Xebec
board and then back to bytes to store in flash memory on the drive
emulator, or vice versa. It would seem logical to simply make a thing
that connects to the SASI port, accepts the commands set of said S1410
controller and stores the data in flash memory directly. Any
suggestions as to how to do that?
Finally, the terminal board has an external video output It's a 5 pn
DIN socket, separate syncs and analpgue video (not composite). There
is a mention of a 12" monitor in one manual, of course with no model
number. Odd, I wouldn't have thought 12" was much of an improvement
over the built-in 9" unit. I would have expected something larger to
show a group of people at once. But making something to connect to
that output is another project.
-tony
I've skimmed the thread about making images of floppy disks. I want to
do the reverse.
But I had better explain. There are 2 subsets of computers here. The
larger subset -- all but one of the machines -- are classic computers.
These machines tend to hve real floppy drives and RS232 ports and not
much else.These machines I understand. I have service/technical
manuals. I have schematics. I can generally figure out how to program
them.
The other set contains one machine. A modern-ish (for me) PC laptop.
It has USB ports. It gets me on the internet (it is the only
internet-connected machine at the moment). It does not have floppy
drives [1]. I do have a USB-RS232 interface -- first thing I bought
for it. I have no proper manuals for it. I do not know how to program
it or interface it.
[1] I think I have a USB floppy drive somewhere, but it'll be a
'1.44Mbyte' [2] 3.5" thing. A type of drive conspiculously absent on
my classic machines.
[2] In quotes becuase it is, of course, nothing of the sort. Well, not
unless you believe a megabyte is 1000*1024 bytes.
Given that the floppy disk images are going to come on the latter
machine, what is the easiest way to get them onto real floppy disks
for my classics. I think it's reasonable to assume they'll be FM or
MFM encoded at the standard rates and that I will have drives capable
of handling the disk. FM of couse rules out using some PC disk
controllers.
I do of course have no objections to making stuff, but I'd rather not
start trying to interface a WD2793 to a Raspberry Pi if there's a
standard way to do things.
-tony
A couple of questions if anyone has experience of this machine :
1) There is a 5 pin DIN socket for connecting an external video
monitor. The signals seem to be TTL-level separate syncs at European
TV rates (15625Hz horizontal, 50Hz vertical) and separate (not
composite) 4-level analogue video.
I believe Philips sold a 12" monitor to connect there. What was the
model number? Is a service manual availabe?
Has anybody linked other monitors to that socket?
2) There is a 50 pin card edge for a SASI interface. I think the
Philips hard disk unit used the Xebec S1410 controller. I've
downloaded the user manual for that from bitsavers which at least
gives me the command set.
Does anyone have experience of a SASI-flash memory interface? Any
recomendations for things to look at? Or should I design my own, it
doesn't appear too hard?
FWIW to tie in to another thread, I like to keep my classic computers
original inside the box but am happy to link up non-standard
peripherals. So My P2000C will keep its 2 internal floppy drives and
CRT monitor. But I would have no problem with hanging an LCD monitor
off that video output socket.
-tony
I don't even remember signing up for the RetroAbout64K mailing list. I haven't seen any actual dicussion in my remembrance. But I do get once or twice a week an email about COCO Nation or some such. Sounds like a hot chocolate enthusiasts group seeking world domination. Anyway I've had COCOs going back. Or 1 that I scarfed from a friend for 20$ (back in 89 I think). I realize it has a 6809 and all, the successor to the venerable 6800. But what can you do with the things? Is there even a color output, despite the name. I can't remember. I only remember playing Dungeons of Daggorath or whatever. The guy I bought it from claimed he programmed a complex naval similation. Yeah whatever.