I assembled Dwight Elvey's KIM-1 debug board (thank you, Gary!) and have now
certified two of my KIMs with it, so I'm very confident the harness operates
properly.
Unfortunately, the one I *want* to repair, my original KIM-1, won't start up at
all after replacing the 2102 RAM I was pretty sure was bad. I checked my
soldering and found a couple spots without continuity that should according to
the schematic, but fixing those didn't fix it. I also buzzed out the socket and
found no obvious shorts, and a second 2102 equivalent from a second
manufacturer has the same symptoms.
I connected the debug harness and test 0, the initial "dead board" test, does
show CPU accesses on the red LED and slowly flashes the green LED, so the CPU
at least is alive and can access the test EPROM.
However, test 1, the RAM test, should show long flashes of the green LED if RAM
is bad. I was prepared to see all long flashes which might implicate the
buffers or address decoder, but instead it won't blink the LED at all in that
or any of the other tests. The red LED remains lit and appropriately
extinguishes when the RS button is down.
Again, the board works correctly and fully certifies the other two KIMs.
What would cause it to hang (?) in the RAM test on the defective one?
--
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser(a)floodgap.com
-- Roger Waters to moving crew: "Hey! Careful with those racks, Eugene!" ------
Hi everyone!
I'm having a horrible time trying to find ntpdate pre-compiled for
Irix 5.3 anywhere. Does anyone have a package/tardist?
--
-Jon
+44 7792 149029
I finally got an IBM 5120 earlier this month, to complement the 5100 and
5110 that I already have.
It had a few issues, but I did manage to get it to "boot" to BASIC.
I put together a few notes about it here. Nothing too exciting, but two
things I've learned: (1) the 5120 does actually still have the video
REVERSE feature. (2) the 5120 has both an external (red power switch) and
internal power switch (internal one is at rear below disk drives).
Notes here:
https://voidstar.blog/ibm-5120-aka-ibm-5110-3/
IBM 5120 (aka IBM 5110-3) — voidstar
<https://voidstar.blog/ibm-5120-aka-ibm-5110-3/>
My only question is: how "universal" are 8" disk? This 5120 only came with
a single IBM 8" Diagnostics disk. It looks to be in fine condition, but
I've no idea about the data.
So far I haven't been able to read it - it's probably more hardware/drive
issues, I'm still investigating. But I'm wondering if I had other 8"
disks (3M SS/SD), should I be able to format/MARK them?
I've used old tape decks and 5.25" drives - but 8" drives is all new
territory for me.
Also, I'll be talking about the 5100/5110 at VCF next Sunday on the 25th of
this month, June.
While looking for my RSX11 DECNET manual (because the online version
doesn't have any examples of commands which is why you look in the
manual in the first place) I found a copy of the DSM binder AA-K676B-TK
and ilk.
Is this online or does anyone else have it?
CZ
I've got a few backup sets (potentially incomplete) done on MicroRSX
that were created with BRU on RX50 media. I've cranked out some code to
itemize the contents, but the file types are a mystery. I suppose that
one has to live in that world to know (e.g. MSL)
The sets appear to be (parts) of an incremental backup scheme; I think
I've got at least one copy of the complete set.
Would anyone be willing to have a look at the (ASCII) file catalog and
suggest the application that may have created the files?
Email me offlist if interested.
--Chuck
So I had a fellow list member show up and trade me an AUI cable for
reading some of his old RX01/02 disks to see if there was anything on
them. Not a big deal, TALOS (my 11/83) has pretty much everything:
11/83 CPU board with FPJ11
MSV11-QD card with 4mb memory (lots o' disk cache)
RXV21 plus RX02 drive
RLV12 plus two RL02 drives (and an RL01 in a pinch)
TQK70 and TK70 tape drive
DELQA Ethernet
DZQ11 4 port serial board
And the MTI ESDI disk controller with a 330mb half height ESDI disk
Overall it's a pretty fast and solid system. I have RT11 on DU4:, RSXM+
on DU0:, and plenty of power to do anything.
However when we fired it up we got nothing on the terminal. Great. So I
went to TITAN, which is another BA23 equipped 11/73 with:
11/73-B board wo FPJ11
2mb memory (Datamation)
TQK70+TK50 (my other TK70 doesn't write properly for some God unknown
reason)
DEQNA Ethernet (it works)
DHV11 8 port serial board
That odd little 3016 real time clock board I never seem to get around to
loading drivers for
RQDX3 jumpered for RD54 running RSX11M+ (not bad with cache)
20mb HH drive with XXDP+ utils
40mb HH drive with RT11 5.4 all drivers (last version that supports the
TU58)
That worked, we were able to move over the RXV21 and read the disks, but
I was wondering what was wrong with my main system. So after he left I
pulled it apart.
Problem seems to be the MTI card was not booting up properly, and since
it holds the Q bus in a frozen state until the disk spins to ready it
was blocking the system. Pulled it, cleaned the pins with 1500 grit
sandpaper, put it back in, it now works. Great.
So every once in awhile I guess I have to check the pins on these old
11's. They run well and are starting to be used more, but they still
have weird problems from time to time.
CZ
Anyone have the 2716 ePROM listing for IMSAI Basic. Version 1.4 or
whatever. I once had it, can't find my copy. If not 2716, I'll take any
listing that I can convert somehow.
Thanks
Bill
I am getting an error message when I boot up a recently donated PCs Limited
XT clone. The error is
ARC Turbo Board
X Turbo System Error # 04
Does anyone have one of these boards, I believe the error means the board
has been removed, and the system can't find it/bad board. If so, please
advise the $$.
I don't think the board is specific to PCs Limted, I found a general manual
called "Turbo-XT Main Board" that seems to be the OEM of the PCs
Limited-branded motherboard. I assume there is a separate daughterboard
the the "Turbo" part. Yes?
Thanks
Bill
So I had always heard the quote "640KB is enough memory" being attributed to
Bill Gates. However, recently I was watching Dave Plummer on YT and he said
that it is not true:
https://youtu.be/bikbJPI-7Kg?t=372
And apparently the man himself has denied it as well but it just will not go
away...
https://abcnews.go.com/Technology/PCWorld/story?id=5214635
So I guess like the napkin/disk story and the DR/IBM story this is another
one of those vintage myths and folk lore with no real basis in reality....
-Ali
As some of you may be aware I am trying to find a fault in a Rainbow H7842
PSU. I am using Tony Duell's schematic from here
http://www.bitsavers.org/pdf/dec/rainbow/duell_schematics/psu.pdf.
I have been testing the Control Module by using a bench PSU to supply 15VDC
to the input of the 7812 regulator (p2, PSU Sheet 1).
My diagnosis shows that the control module is shutting down the PWM (p6,
Control Module Sheet 2) because it is detecting an overcurrent in the -12V
side (E3d on Control Module sheet 1, although I have determined that it is
actually E3c).
This seems to be because I measure a steady 0.6V on pin 6 of the transformer
(p4, PSU Sheet 3). I just can't imagine where it might be coming from as the
chopper won't be running. I had previously removed the transformer and there
are no shorts between the pin 5-pin 6 winding and any of the other pins on
the transformer. I checked all the DC outputs of the PSU when powering the
7812 from the bench, both on a working PSU and the non-working one. They are
all at zero except the -12V output on the non-working PSU, which is +0.6V.
But the voltage can't come out of nowhere.
I am stumped and would appreciate any suggestions.
Thanks
Rob
