> There's a partial CE Service Handbook, here:
> http://www.hpmuseum.net/exhibit.php?hwdoc=555
Hi Mike, thanks for the steer.
That manual is interesting but does not seem to contain any of the basic operating procedure.
e.g. I guess that it is OK to power the drive down with a cartridge in situ but will the drive attempt to spin up and load the heads if I power it up?
>I'll check what is in the backlog. I have hundreds of HP manuals scanned but not post-processed.
Hi Al, many thanks.
It would be great to have a set of schematics and/or user's guide before I start working on the drive
Hi Christian
Many thanks for the steer - I had hoped that it might be something like this. Was surprised that the failed component did not heat up / smoke.
> On Fri, 14 Feb 2014, Peter Brown wrote:
> > I have just pulled my HP 7907A out of storage and tried to power it up.
> > No joy, it emitted a couple of squeaks from the power supply and that
> > was it.
>
> If the power supply squeaks most probably there is a short on one of the
> outputs; perhaps a shorted tantalum or electrolytic?
>
> Christian
Maybe someone has a spare IIe motherboard revision b around? Even broken?
Got a local IIE (s/n below 10000 with white lettering) but it doesnt have
dhgr, so i want it to be usable everyday and not another hangar queen.
Of course, a duodisk unit and some useful cards (any ramworks even without
memory, transwarp, grappler+, microsoft softcard, appli-card, ramfactor...)
would be welcome :) an original joystick and koala pad too :) i just love
apple!
Thanks :)
Alexandre
>On Sun, Feb 16, 2014 at 4:14 PM, Charles
><charlesmorris800 at centurytel.net> wrote:
>> I have a hex-height (Omnibus) board in my junk box... M8549 "Universal
>> Substitute Board". It has a few 10101 (ECL??) IC's. Here is a picture
>> of both sides.
>>
>> http://s1181.photobucket.com/user/DrCharlesMorris/library/PDP-8
>>
>> Anyone know what this is for, and any schematic info? I can't find it
>> on any module list.
>
>ECL makes me think "PDP-10". The fact that it has signals on the "F"
>finger tells me that it's not an OMNIBUS board - those use A-D for the
>OMNIBUS itself, and memory cards/memory controllers can use the "E"
>finger for the extra address lines. Nothing in a PDP-8 uses "F".
>
>I don't have an exhaustive card list handy, but see what else shares
>the M85xx range. Related boards often have sequential or
>nearly-sequential handle numbers.
>
>-ethan
I eventually found a huge (150+ MB)exhaustive DEC module list online
which had the M8549 board. You are right, it's part of a KL10 system,
about which I have been reading on various websites.
Presumably someone mistakenly thought, as I did, that it was an
Omnibus board! Glad I didn't plug it in my 8/A.
So, since I don't have room (or power) for a PDP-10, would anyone like
this board for cheap, before it goes to that auction site? Make me an
offer ;)
-Charles
My PDP-8/A with two 16K core boards has developed a flaky bit on one
of the boards. The failure is always in the LSB (11), but there is no
pattern to the addresses that I can discern.
The +20 volt supply appears to be ok (as is +/- 15 and +/- 5)... it
was 19.86v, but adjusting it to 20.00 didn't help.
DHKMAD.DG runs beautifully with only the lower 16k installed. But
while testing the upper 16k, eventually (30 sec. to several minutes) a
random word will fail with its LSB (Bit 11) in the wrong state.
Usually 1 when it should be 0 but *not* always!
Often this bombs the diagnostic program itself (I suppose if it's
self-relocated to the upper field). So far the failures have all been
in field 6 or 7.
Any tips for checking currents/timing? Or should I just replace the
G650, the H219B core stack, or both as a pair? They aren't easy to
find these days and my small chassis only has room for two core boards
that occupy two hex slots each - so they both have to be 16K boards,
as ADVENT requires 32K even though OS/8 runs in 12K :(
-Charles
I have one of the above systems. ?I acquired it about a decade ago sans power cord. ?The power cord isn't the standard one we are used to?today.. and uses differebt polarities.. I simply didn't know enough at the time to purchase one. ?Recently though I did.. and have gotten it to power up and operate, although at times it seems to not want to do anything at all and sometimes requires a few power cycles to get going.?
My question to the community is.. does anyone else put there have one of these? ?And do any of you have a manual? ?I've googled all over but its useless. ?I'm also hoping to one day find the expansion board for it that allowed it to run BASIC. ?If anyone has a line on these. ?I'd be most interested.
Thanks!
Sent from Samsung Mobile
Hi, guys.? I have some very old programs that require Win 95 to run, and I've been trying to use Virtual Box to do that.? I installed Virtual Box on my new Windows 8.1 computer, but when I tried to install Win 95 it refused to recognize my perfectly good Win 95 installation disk (with a valid licensing code) as a real O.S..? Then it turned out that the new computer has a hardware problem, and I've lost access to it for at least a week while it's in the shop being repaired (no, the hardware problem was not at fault; the Win 8.1 computer was just having trouble charging, but it was fully charged when I was trying to install Win 95).
So now I'm back to my old Windows 7 laptop.? I downloaded the latest version of Virtual Box, which says it's for both 32-bit and 64-bit versions of Windows, but when I tried to install itWindows said it wasn't a valid 32-bit program.? Does anyone know which version I need?? And does anyone know how to make it recognize my old Win 95 installation disk as a valid OS?
Thanks for recommending this program; I found out about it here.? And thanks in advance for your help with this problem.
Margret
I have a hex-height (Omnibus) board in my junk box... M8549 "Universal
Substitute Board". It has a few 10101 (ECL??) IC's. Here is a picture
of both sides.
http://s1181.photobucket.com/user/DrCharlesMorris/library/PDP-8
Anyone know what this is for, and any schematic info? I can't find it
on any module list.
thanks
Charles
>On Sun, Feb 16, 2014 at 4:14 PM, Charles
><charlesmorris800 at centurytel.net> wrote:
>> I have a hex-height (Omnibus) board in my junk box... M8549 "Universal
>> Substitute Board". It has a few 10101 (ECL??) IC's. Here is a picture
>> of both sides.
>>
>> http://s1181.photobucket.com/user/DrCharlesMorris/library/PDP-8
>>
>> Anyone know what this is for, and any schematic info? I can't find it
>> on any module list.
--- I found the M8549 used in two places on the document found here:
https://archive.org/details/bitsavers_decpdp10KL_1264444
The classification hierarchy lists the system it's used in under:
DEC::PDP10::KL10::MF20
The MF20 document is titled, "MOS Memory." Note that the M8549 instances are shown with suffixes: YA, YB, YD.
Steve L.
