Hi all,
I?ve been struggling getting a 64k Dynamic RAM card back up and working in my IMSAI 8080. In fact I?m giving up on the DRAM card in this system and have decided to start looking for a SRAM card that can get the IMSAI up to 56k.
In terms if SRAM cards, I presently have:
2 x Problem solver RAM16 cards - both seem to be working.
2 x 8K RAM cards - both seem to be working.
Less cards generating heat, and putting stress on the old power supply is obviously best, so I?d be looking for either:
- 1 x 16k SRAM card (for a total of 4 RAM cards (3 x 16k + 1 x 8k) in my system). A PSS RAM16 would be preferred for sake of consistency, but obviously not crucial.
- 1 x 32k SRAM card (for a total of 3 RAM cards (1 x 32k, 1 x 16k + 1 x 8k) in my system)
- 1 x 64k SRAM card that can have the last 8k bank turned off
I would love to hear from anyone with one of the above cards who would be willing to pass it on.
Much thanks for your time.
Best regards
Philip
> From: Brian Walenz
>> Werner Buchholz (editor), "Planning a Computer System: Project
>> Stretch", McGraw-Hill, New York, 1962
> http://ed-thelen.org/comp-hist/IBM-7030-Planning-McJones.pdf
Yeah, I found that _after_ I sent the email, sigh...
>> Speaking of books, there's also a CDC 6600 book:
>> Jim E. Thornton, "Design of A Computer: The Control Data 6600",
>> Scott, Foresman, Glenview, 1970
> http://www.textfiles.com/bitsavers/pdf/cdc/6x00/books/DesignOfAComputer_CDC…
Didn't know that one was online too - excellent.
>> Really gotta do that Bibliography!
> Where is this 'computer history wiki', anyway?
http://gunkies.org/wiki/Main_Page
Note; automatic account creation is disabled to prevent spamming issues. You
have to email Tore directly - and he is often busy, so it may take a bit.
Noel
Hello Mark,
when you are ready with your machine up and running,
you could try to use on a real Nova 3 the tool I wrote to raw read/write
disks and tapes through the serial port.
You just need a PC (linux preferred) and Python installed (plus serial
port module).
Then you should be able to dump the disk to image for SIMH, and
eventually to write back an image to the disk.
Thanks
Andrea
> From: Mark J. Blair
> An interface card schematic has appeared in my inbox as if by magic.
If that allows you to create a list of what various 8000-series chips do (or
if you've since located one), that would be a good thing to have available
online. If you have (or create) one, we can stick it on the Computer History
wiki...
Noel
> From: Al Kossow aek at bitsavers.org
> which one?
> 1974_Field_Service_Technical_Manual_Dec74.pdf
> is already on line under handbooks
Dat be de one. Alas for the OP, it doesn't seem to contain any PDP-11 stuff
(well, a bit on the RK11-C, etc, but nothing on any processor, at least that
I could see).
FWIW, it's available online on an indexed, page-by-page basis at:
http://www.pdp8online.com/bklatt/TechTips.html
Worth looking through.
Some of them are amusing, like "Disk Destruction Made Simple" and "DECtape
Reels Falling Off Drive".
Noel
Maybe a year ago I got two metal 3 shelf library carts on wheels, to hold
the manuals that were related to whatever machine I was working on at the
time. Its extremely useful to have all the manuals at hand on a rolling
stand when you're moving around working on the beast. I have not seen any
for sale since then at a reasonable price (which I'd say is $100 or less).
I just stopped at a place here in St. Louis, and I see they have 8 of these
"library/book carts" available. They are basically in mint condition, and
most of them come with old red binders on 2 of the 3 shelves. The binders
are interesting - these are those old ones with sort of cloth surfaces and
heavy metal latches inside. All the binders are about 3 or 3.5 inch wide. A
typical place I see these type of binders is in machine shops and the like,
holding press setup instructions and such. The binders are old, but the
carts are basically new looking. The carts are 42.5" tall, 31" wide, and 13"
deep. The carts hold books on one side only, and the height of each shelf
between the next is 11 & 5/8. If your binders are taller than that they
won't fit ;) $75 each.
Here is a link to an almost-but-not-quite-identical cart:
http://tinyurl.com/huamv7e
I'm buying 2 of these for myself, leaving six. I'd be happy to purchase and
hold for a while if someone non-local wants some, but it's probably not
economical to ship them. I could deliver one or two to VCFMW this year
perhaps.
J
> From: Fritz Mueller fritzm at fritzm.org
> Are DEC ECO's available online anywhere? ... I am particularly
> interested in ECO's related to the KB11-A (11/45).
I have a DEC Field Circus handbook arriving today that allegedly contains
some ECO information; if there's anything on the KB11-A, I'll see if I can
get it scanned.
Noel
>
> Date: Tue, 21 Jun 2016 18:08:49 -0700
> From: Glen Slick <glen.slick at gmail.com>
> Subject: Re: PDP-11/40 modified to be a PDP-11/23
>
> What boards exactly? Are you sure it's not an M7133 11/24 board instead?
>
> From front to back in the AB slots:
- M8186, KDF11-A, 11/23 CPU, 18-bit addressing only
- M8044-DM, MSV11-DD, 32-Kword 16-bit MOS RAM
- M8043, DLVJ1-M, 4-Line Asynchronous Interface
- M7940, DLV11, Serial Line Unit (SLU, Async)
A custom interface to the front panel is in the CD connectors of the first
slot.
I will post pictures of the boards on the RICM WWW site.
--
Michael Thompson
The testing that I've been doing so far to get the 6045 hard drive working on my Nova 3 suggests that the interface card receives commands over the IO channel (i.e., I can command seeks and get the expected clunking sounds from the drive). But the interface card does not appear to be responding back to the CPU so far, since attempts to read the three IO registers or the busy/done flags always return zeros. So, I'll need to move on to component-level debugging of the interface card now.
I'll need to have access to the interface card, of course. The first step was to swap the positions of my Nova rack and my VAX-11/730 to get the right side of the Nova away from the wall. This wasn't easy in the tiny, cluttered room that they live in.
Next, I lowered the Nova 2 rack units, because it was in the top rack position and I couldn't get access to all of the top cover screws to get the top cover off. Damn, that thing is heavy! I pressed my hydraulic lift hand truck into service. There was a 2U filler panel under the Nova that can now live at the top of the rack, so there will be no need to raise the Nova back up later.
With the top of the Nova accessible, I removed the quad serial mux in slot 12 to expose the component side of the disk interface card in slot 11. There are 6 empty slots under the interface card, so I have good access to both sides of the interface card, as well as the backplane.
Now I should be able to do things such as running a tight loop reading or writing a controller card register while I probe the logic. Should be simple, right? Well, it would be if I had a schematic diagram of the interface card. So, I'm doing this in hard mode. I decided to do a little preliminary trace identification on the card before going to bed tonight, and that's when I discovered that this game is in very hard mode: Most of the ICs on the controller card are marked with a DG logo and an 8000-series number, and I have no documentation about those chips yet. The busy/done flags come out of a DG 8109, but what the heck is that? I hope that they'll end up being rebadged 7400 series chips or something like that so I'll have some chance of finding replacements, but I'll need to figure out how to identify these DG chips before I can make much progress debugging the card.
I've been looking through the documentation that I have, as well as looking in documents on Bitsavers for DG gear other than the Nova 3 in hopes of finding anything identifying these 8000-series chips. I haven't found the decoder key so far. If anybody out there in cctalk land knows about DG-marked 8000-series logic chips, I would appreciate any help very much!
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
The RICM just picked up a PDP-11/40 chassis that was modified to accept a
PDP-11/23 board set. It also contains a custom board to interface the
PDP-11/23 to the original PDP-11/40 front panel. It is quite an
accomplishment to get the Q-Bus board set working in the Unibus chassis.
--
Michael Thompson
