Old IBM magnetic media
Yes, two cartridges have a total capacity of 100mb, the same as the staging
disks, IBM 3330-1.
However, the entire cartridge contents are not staged, only the cylinders
that have the requested data.
Not sure why your cartridges were empty.
Here?s a link to my ?working ? 3850 mass storage robotic arm for your
viewing pleasure!
*https://www.youtube.com/watch?v=V8ifNxDgxuY&pbjreload=10*
<https://www.youtube.com/watch?v=V8ifNxDgxuY&pbjreload=10>
?\_(?)_/?
So I picked up an 11/84 CPU, 3mb of memory, and a 11/84 Unibus card on
Ebay. Goal is to speed up my fastest 11 here
For boot time, the diagnostics run in 13 seconds (from when it starts to
prompt) on the 11/73 board I have and 13 seconds on the 11/84 board.
This is with a camintonn 2mb half height memory board.
Put in the first PMI module above the 11/84 CPU and tried it out. This
is a CA rev board which apparently only works in a Unibus pdp11 and not
a Q-bus one. Apparently it does work.
So what exactly was the bug with the older PMI memory? Block mode DMA,
I'm using an MTI ESDI controller which can do 16 word block DMA on Q
Bus. Something else?
Here's the output from RT11.
.show all
RT-11FB (S) V05.05
Booted from DU6:RT11FB
USR is set SWAP
EXIT is set SWAP
KMON is set NOIND
TT is set NOQUIET
ERROR is set ERROR
SL is set OFF
EDIT is set KED
FORTRAN is set FORTRA
KMON nesting depth is 3
Global .SCCA flag is disabled
PDP 11/83 Processor
2048KB of memory
Floating Point Accelerator Unit
Extended Instruction Set (EIS)
Memory Management Unit
ECC Memory
Cache Memory
PMI Memory
60 Cycle System Clock
Device I/O time-out support
Error logging support
Memory parity support
System job support
Global .SCCA support
FPU support
Extended unit support
Device Status CSR Vector(s)
------ ------ --- ---------
EL Not installed 000000 000
LD Installed 000000 000
BA Installed 000000 000
DY Not installed 177170 264
VM Installed 177572 250
SP Installed 000000 110
XL Not installed 176500 300 304
DL Installed 174400 160
MS Not installed 172522 224
DU Resident 172150 154
LS Not installed 176510 310 314
NL Installed 000000 000
TT (Resident)
DU (Resident)
DU6 = DK , SY
MQ (Resident)
LD
DL
VM
SP
BA
NL
9 free slots
Job Name Console Level State Low High Impure
--- ---- ------- ----- ----- --- ---- ------
0 RESORC 0 0 Run 000000 103232 105046
No multi-terminal support
Address Module Words
------- ------ -----
160000 IOPAGE 4096.
132174 DU 5570.
103274 RMON 5856.
001000 ..BG.. 16990.
LD0 is DU6:RTTST.DSK[6000.]
OK Looking to purchase "Sensicall" and the ATT Code-Com" bell system attachment that woukd allow deaf to tap morse over phone lines? thanks? Ed? at? SMECC
Looking to purchase CODE A PHONE? bell system attachment that woukd allow,deaf to send morse code through bell system phone.? Respond off list...... they would tap on litte finger pad . this,was,an attachment to a regular phone,set made in later 60s or 70s. Person on other end would see light flash I guess... drop us a line off list.
>
> Guys,
>
> I have been collecting all types of computer punched cards for a few years
> now. In the distant past I actually used them!
>
> I am desperately looking for two types I do not have been able to find a
> sample of:
> * Jacquard fabric/carpet loom cards. OK, not computer but the
> ancestor, for completeness of the history. There may be several formats of
> these.
>
>
Something like this?
http://www.ricomputermuseum.org/Home/interesting_computer_items/jacquard-lo…
--
Michael Thompson
Guys,
I have been collecting all types of computer punched cards for a few years
now. In the distant past I actually used them!
I am desperately looking for two types I do not have been able to find a
sample of:
* Jacquard fabric/carpet loom cards. OK, not computer but the
ancestor, for completeness of the history. There may be several formats of
these.
* Original Hollerith card, 12 rows by 24 columns. Once again, this is
a long shot.
Well if you don't ask, you never get! Thank you for your interest. Peter
I have another PSU I have been meaning to look at for a long time. This one
has fairly high output ripple and some of the voltages do not appear to be
where they should be. I have checked all the capacitors for ESR and they
appear to be OK, with the exception of the two big smoothing capacitors on
the primary side. One of them appears to be slightly bulging, but has
low-ish ESR, the other has a much higher ESR. Is it possible that these
capacitors could be the cause of the out-of-spec outputs?
Thanks
Rob
Some of you may recall seeing me post about the VAXmate PSU failure. Thanks
to members of this list I found the failed part in the PSU and the PSU is
now working again. However, it looks like the PSU failed because of a
failure on the monitor board. There is a burning smell coming from it,
possibly the flyback transformer, but I am not 100% sure. I don't see
physical damage, but of course that doesn't mean there isn't a problem. When
I took the monitor board out again after this, I wasn't sure if the EHT lead
was making good contact with the CRT anode. The monitor board is described
in section 4.4 of this document:
http://bitsavers.org/pdf/dec/vaxmate/EK-PC500-TD_VAXmate_Technical_Descripti
on_1987.pdf
I need some advice on diagnosing the problem, I have a few questions:
1. If the EHT lead was not properly connected to the CRT anode, could
that cause problems?
2. Is there anything I can safely do with a bench power supply to
isolate the problem?
3. Any other suggestions for diagnosing the problem?
4. There is an outline spec of the flyback transformer in the section
4.4.3.2 of the VAXmate technical description, what chance of finding a
"modern" replacement?
I have posted about the PSU repair here:
https://robs-old-computers.com/2020/04/18/vaxmate-h7270-psu-fixed-but-no-vid
eo/
Thanks
Rob
At 10:00 AM 4/17/2020, Bob Smith <bobsmithofd at gmail.com> wrote:
>...I believe sometime in the late 70s, maybe as late as 1980, a prof
>associated with UMass wrote a paper describing an extension of the
>PDP8 called 8/X or 8X.
>...I believe, my memory is fuzzy, that it was a prof nnmed Stone or
>Stoner (perhaps Harold S) who lead the effort and had his name on the
>paper.
That is probably Harold S. Stone, whom I knew as a Stanford prof in
the early 1970s and did some corporate consulting with. Brilliant
guy. From 1974 to 1984 he was at UMass Amherst, so your memory isn't
fuzzy at all. He also worked at the IBM Yorktown Heights research
center. He was the author of several books and many papers about
computer architecture, algorithms, and interfaces.
Unfortunately I don't remember him working on a PDP-8 extension, and
a quick search of the ACM Digital Library turned up nothing. As far
as I know he's still alive at the age of 82.
