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
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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?
