• Please review our updated Terms and Rules here
  • Exhibitor application for VCF West 2022 is now open! If you are interested in exhibiting, please fill out the form here.
  • Here are the results of the VCF East 2022 Post Event Survey: Survey Results

Getting a CCS 2810 Z80-based S-100 system running again

nullvalue

Experienced Member
Joined
Oct 8, 2019
Messages
464
Location
Indiana
So I purchased this large S-100 lot from a the original owner. He ran his business throughout the 80's on it. Stored it away and it hasn't been used in 25 years or more.

ci8p8g4vq9o61.jpg 20210321_084946.jpg 20210323_211056.jpg

It has the following boards:
  • California Computer Systems (CCS) 2810 Z-80 CPU
  • Scitronics Real Time Clock
  • Tarbell MD2022 FDD Controller
  • (4) Memory Merchant 64K Static Memory
  • Solid State Music (SSM) IO-8 (<-- I do have the original manual for this, which it looks like people have been looking for)
  • Solid State Music (SSM) IO-4

In has a 21-slot TEI backplane in a TEI case. There is another enclosure which has (4!) 8" floppy drives. 2 are the Siemens 120-8, and 2 are the Qumetrack 842. I only have one floppy disk that came with it marked "System" which I will try to get booting later. I'm assuming it's MP/M since it said it was a 4-user system and I got a bunch of MP/M manuals with it. I also have the original manuals for most of these boards.

For now I am just trying to get into the monitor since the CCS 2810 has a built-in ROM. So, I started the main unit up with no boards to check levels - all voltage supplies are spot on. The only cards I have installed currently are the 2810 and the IO-8 (since it's port A was configured for Terminal 0). I jumpered the 2810 to run the ROM (ROM EN, JMP EN, JMP ADDR SEL set as indicated in the manual) but am getting nothing out on the terminal. Do I have to use the 2810's internal serial port in order to use the ROM? Currently SER EN is OFF. If so, how would I construct a cable? (the board has a 26-pin header). I depending on what cards I install, I will get the HALT LED come on. In the current configuration it does not come on.
 

jlang

Experienced Member
Joined
Sep 25, 2014
Messages
146
Location
central florida
I made the cable for my 2810 by crimping a 26 pin IDC connector to flat cable to 25 pin D-shell female connector. This gets you a 25 pin D wired as a DCE.
That matches serial terminals and PCs wired as DTE.

joe
 

nullvalue

Experienced Member
Joined
Oct 8, 2019
Messages
464
Location
Indiana
I made the cable for my 2810 by crimping a 26 pin IDC connector to flat cable to 25 pin D-shell female connector. This gets you a 25 pin D wired as a DCE.
That matches serial terminals and PCs wired as DTE.

joe

So is that right that the monitor will only work with the 2810's serial port? Could you share a picture of your cable? I want to make sure I get the directions right.
 

jlang

Experienced Member
Joined
Sep 25, 2014
Messages
146
Location
central florida
So is that right that the monitor will only work with the 2810's serial port? Could you share a picture of your cable? I want to make sure I get the directions right.

Yes the CCS monitor expects to use the serial port on the 2810 board.
Addressed at 20h

Photo of cable may be attached.... can't really tell

joe
 

Attachments

  • IMG_0539.jpeg
    IMG_0539.jpeg
    89.2 KB · Views: 1

nullvalue

Experienced Member
Joined
Oct 8, 2019
Messages
464
Location
Indiana
I don't have any crimping tools - what would I need to build a cable like this? I could I just splice it by hand? Are the pins just hooked up 1:1, and it looks like you just leave off #26 from the cable? Do I really need to hook up all 25 lines or only like 8 or 9 of them?

I do have these - that should work, right? Do I need a special tool or just push it down by hand? https://www.ebay.com/itm/174346909156 I just seen in a video you can use a vise.. I'll give that a go.
 
Last edited:

jlang

Experienced Member
Joined
Sep 25, 2014
Messages
146
Location
central florida
For the D-shell connectors I just crimp them in a vise. I use a "scrap" connector
(no pins just housing) to protect the male pins. You just mate them and apply
pressure with the vise.

For the IDC connectors the pins are not exposed so just put in the vise and squeeze.

All 25 pins are not needed. You really only need 3 wires if you are not doing flow control. 2

Dshell 26PIN
2 3 in
3 5 out
7 13 ground

It just looks a lot cleaner to use the crimp stuff.

joe
 

nullvalue

Experienced Member
Joined
Oct 8, 2019
Messages
464
Location
Indiana
Ok so I crimped together the cable - I was lucky I already had that part.. However, same as before - nothing at the terminal. I also set SER EN to On. The manual (unless I missed it) wasn't real clear on what the baud rate is or how to change it. My terminal is set at 19,200. Do you know what the 2810 is?
 

nullvalue

Experienced Member
Joined
Oct 8, 2019
Messages
464
Location
Indiana
Ok so after reading the manual more closely, it mentions needing some RAM to load properly. So after adding a RAM board to the configuration, the ROM EN led comes on and I got into the MOSS 2.2 monitor! Progress!
 

nullvalue

Experienced Member
Joined
Oct 8, 2019
Messages
464
Location
Indiana
The monitor has a built in RAM test function and I'd like to test all 4 RAM boards that I have. However, I am still pretty new to S-100 computers and am unsure how/where to address the RAM. Do I have to test each 64k board at a time? The Test command expects a start/end address. How do I figure out what values to use?
 

jlang

Experienced Member
Joined
Sep 25, 2014
Messages
146
Location
central florida
The 2810 can only address 64k (16 bit address bus). I expect the memory is bank switched.
Writing to some (unknown) IO port with some (unknown) bit pattern selects the memory
that responds.

I'm assuming the sytem is configured for MP/M so:
My advice is write down every switch and jumper setting on the memory boards.
It may be difficult to get back to the "as received" condition with out that.
And get the manual for the memory boards.

joe
 

nullvalue

Experienced Member
Joined
Oct 8, 2019
Messages
464
Location
Indiana
Ok, I think I understand most of that. I will read through the memory manual. Though, for now - with just one memory card installed when I run a test 0000-EFFF, it works (no errors reported).. F000-FFFF throws errors - I'm assuming because the ROM itself begins at F000? So using the ROM is it not really possible to test memory locations from F000-FFFF?

EDIT: So after reviewing the manual and the current switch settings, all boards are set to Bank Select at port 40H. Data bits on the 4 boards are set 0-3. So the 2810 manual indicates to write to a port, use 'O' followed by the port and data to write. So to select bank 2 would I enter "O40 2<return>"?
 
Last edited:
Top