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CCS S-100 woes

QuantumII

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Hi

I'll start a new topic here regarding getting the CCS system running.

Old discussion is here

Long story short, I got a CCS S-100 system for free a while ago, which I cannot get to work properly.


It has those cards inside, all CCS:

- CCS 2065 64K RAM
- CCS 2422 FDC
- CCS 2810 CPU
- CCS Paralell/Serial card

Manuals are here
In addition I have those two cards (Not inside the system)

- Cromemco DPU
- Cromemco STDC

The system does not work, and below is the last results from my tests:

I measured the voltages and they seem OK.
I cleaned the CCS CPU Card and replaced all the corroded jumpers. I reseated _every_ chip on the card and followed the manual in how to enable the built-in monitor.

No response over serial whatsoever. No garbage, no nothing. The LED's on the card does not light up, and if I put in the memory card, the LED on the memory card does not light up either..

If I put in the Cromemco DPU card things start to act a little different. The Memory card lights up, the floppy controller flashes it's "sel" LED and the two others are on solid. On the DPU card the "Z80" LED lights up.

Nothing on the serial port.

Based on the above, I am almost certain that the CCS CPU card is wasted one way or another. The only thing that gets hot is the Z80 CPU and the voltage regulator.

The Cromemco DPU card is probably working, but does nothing useful as it does not have a serial port. I just put it inside the case to see if it did anything.

Any suggestions on what I can try to get the CCS CPU card working, and does it require to have a RAM board in the system to actually work or can it work entirely on its own ?
 

per

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Check the input voltages of the Z80. I don't think such old CPU's should get hot...

If you got an osclioscope, you may try to check the clock input/A0/D0 pins if there is any activity. IIRC, Z80 CPUs are still availble.
 

cosam

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I measured the voltages and they seem OK.
I cleaned the CCS CPU Card and replaced all the corroded jumpers. I reseated _every_ chip on the card and followed the manual in how to enable the built-in monitor.
Good start!

No response over serial whatsoever. No garbage, no nothing. The LED's on the card does not light up, and if I put in the memory card, the LED on the memory card does not light up either..
What are the LEDs meant to do?

Based on the above, I am almost certain that the CCS CPU card is wasted one way or another. The only thing that gets hot is the Z80 CPU and the voltage regulator.

Any suggestions on what I can try to get the CCS CPU card working, and does it require to have a RAM board in the system to actually work or can it work entirely on its own ?
One quick check: is the refresh jumper set correctly for the memory board you're using?

After a quick skim over the manual, I don't see anything about there being any RAM on the CPU board. If there's indeed no RAM there, you will need the memory board to do anything useful.

What you can check depends on what you have to check with. With a multimeter or logic probe you can at least check if the CPU is stuck (e.g. if RESET, INT, NMI or WAIT asserted). If you have a scope you could check the clock input and whether the busses are doing anything at all.

Oh, and double/triple check your wiring and settings on the serial port.
 
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QuantumII

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Good start!


What are the LEDs meant to do?


One quick check: is the refresh jumper set correctly for the memory board you're using?

After a quick skim over the manual, I don't see anything about there being any RAM on the CPU board. If there's indeed no RAM there, you will need the memory board to do anything useful.

What you can check depends on what you have to check with. With a multimeter or logic probe you can at least check if the CPU is stuck (e.g. if RESET, INT, NMI or WAIT asserted). If you have a scope you could check the clock input and whether the busses are doing anything at all.

Oh, and double/triple check your wiring and settings on the serial port.

Ok, I'll look at the memory board today. It has corrosion on all jumpers as well, so this might screw something up.

I currently only have access to a multimeter, so how can I use it to check the CPU?

There's a lot of _expensive_ logic analyzers and scopes and whatnot here at work, but I doubt if I am allowed to take one home for experimenting.

Per, I tried with another Z-80 (I have a few) and no difference.

I don't remember what the LED's are for, but I think it's WAIT and HLT. The memory card has a LED which is supposed to light up when it's accesed, and with the CCS CPU card nothing lighs up. If I replace the CCS CPU card with the Cromenco DPU, the memory card LED lights up.
 

QuantumII

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If the voltages are off, replacing the CPU doesn't help.

Pin 11 should be +5v, Pin 29 should be Ground, Pin 6 should be Clock.

OK, so between Pin 11 & Pin 29 I should get +/- +5v. I'll check tonight when I get home.
 

cosam

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Ok, I'll look at the memory board today. It has corrosion on all jumpers as well, so this might screw something up.

I currently only have access to a multimeter, so how can I use it to check the CPU?
I would check VCC first as Per suggests. If that checks out, measure the voltage at the pins mentioned in my last post - they should all be high. You can do this with and without the memory board and see if there's any difference.

There's a lot of _expensive_ logic analyzers and scopes and whatnot here at work, but I doubt if I am allowed to take one home for experimenting.
If it gets that far, maybe you could take the computer along and have some time on the equipment during lunch or after hours? Turning up with an S100 box might even stir up some interest in a helpful technician or two ;-)

I don't remember what the LED's are for, but I think it's WAIT and HLT. The memory card has a LED which is supposed to light up when it's accesed, and with the CCS CPU card nothing lighs up. If I replace the CCS CPU card with the Cromenco DPU, the memory card LED lights up.
In that case it's probably a good thing that the LEDs on the CPU are off. I would expect the one on the memory card to show some activity at start-up, if only very briefly. I don't think it's normal for it to be on all the time either.
 

billdeg

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I have a Series 2200. For the longest time I thought it was dead, but then I got an in-circuit emulator (ICE) and I learned that the CPU and memory were actually fine. I was also able to check memory locations to determine that the disk boot loader was being written to RAM as well, I just did not have the correct version of CP/M and a drive. These systems were sold to be booted from disk. See if you can return the system to the original configuration.

I would start with just the CPU card and RAM. Once you know the voltages are OK with that, add the disk controller. I am guessing that your monitor or the CP/M made for this system is set to a specific address, and will send serial output specific to the serial card that came with the system matching that address. Anything else would return "nothing" and it would seem like the computer was not working. Also, the CSS's are very quiet.

Bill
 

QuantumII

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I have a Series 2200. For the longest time I thought it was dead, but then I got an in-circuit emulator (ICE) and I learned that the CPU and memory were actually fine. I was also able to check memory locations to determine that the disk boot loader was being written to RAM as well, I just did not have the correct version of CP/M and a drive. These systems were sold to be booted from disk. See if you can return the system to the original configuration.

I would start with just the CPU card and RAM. Once you know the voltages are OK with that, add the disk controller. I am guessing that your monitor or the CP/M made for this system is set to a specific address, and will send serial output specific to the serial card that came with the system matching that address. Anything else would return "nothing" and it would seem like the computer was not working. Also, the CSS's are very quiet.

Bill

Hi , just a quick reply (Im on my way out)

The CPU board has its own Serial port which can be used with the monitor. See the manual :)
 

per

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Hi , just a quick reply (Im on my way out)

The CPU board has its own Serial port which can be used with the monitor. See the manual :)

Since the FDC is compatible with the Tandon drives used by IBM in the PCs and XTs, wouldn't it work to write a small bootloader and write it to the boot location of a DD 5.25" disk on a PC?

Just a guess...
 

billdeg

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so far I have not been able to get it to work. I have the card and the cable that outputs the serial signal. I have read the manual. How do you get a bootstrap in there? I need a compatible bootstrap, or a way to force one in. Can you help?
Bill
 

per

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so far I have not been able to get it to work. I have the card and the cable that outputs the serial signal. I have read the manual. How do you get a bootstrap in there? I need a compatible bootstrap, or a way to force one in. Can you help?
Bill

first of all, it all depends on what format the disks are in. The FDC is comaptible with the DD (48 tpi.) TD-100 drives used in the PCs, but how it reads the disks depends on the controller. In PCs, the boot code is located at sector 0, track 0, side 0. Also, in PCs there is 512 bytes per sector, 8 or 9 sectors per track, 40 tracks per side, and one or two sides. All of this may change (well, maybe not tracks-per-side), and it have to mach the controller in the CCS.

To find out how the bootstrap loader works, we should dump the ROM on the FDC and dissassemble it. That's problably the hardest work.
 

billdeg

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I have neither a drive nor a prom card with monitor/bootstrap. I could just stick a North* controller and boot that way I suppose, but I would still need to configure the OS to the particular serial IO card I have. I have been too busy with other stuff I guess, but it's something I will eventually get working.

What I meant by my earlier post was to say that yes you can use the serial I/O on the CPU card, but you need a bootstrap monitor and/or OS of some kind or it's worthless!

Bill
 

Chuck(G)

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If you really want to diagnose some problems, you need something to sniff out whether or not a pin is changing state.

Invest in a logic probe--almost any decent electronics store dealing with hobbyist trade should have them--they're very inexpensive and usually have at least 3 LEDs on them. One LED for a "high" level; one for "low" and one that indicates that a pulse has been seen "a pulse stretcher".

With such a probe you can answer questions such as "is there a clock signal on the CPU?" or "are the data lines changing state?". The logic probe is always my first choice before an oscilloscope or logic analyzer.
 

billdeg

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I am not sure if you mean me or the original poster of this thread. In my case I use an Z80 ICE to check memory. Doing so, I found that everything works. I just don't have a drive controller or bootstrap for this particular system to go any farther. It's a to-do.

If you did not mean me...nevermind! :)


Bill

FURTHER - I have used the ICE to test memory, write/read memory, check memory locations for programs such as the Morrow disk controller's programming, etc.
 
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QuantumII

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I have neither a drive nor a prom card with monitor/bootstrap. I could just stick a North* controller and boot that way I suppose, but I would still need to configure the OS to the particular serial IO card I have. I have been too busy with other stuff I guess, but it's something I will eventually get working.

What I meant by my earlier post was to say that yes you can use the serial I/O on the CPU card, but you need a bootstrap monitor and/or OS of some kind or it's worthless!

Bill

As far as I understood from the manual, the CPU card (The one I have) has a built-in monitor which can be "booted" by enabling Jump and selecting the monitors jump location by using the jump address jumpers.

What CPU card do you have ?
 

Chuck(G)

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I am not sure if you mean me or the original poster of this thread. In my case I use an Z80 ICE to check memory. Doing so, I found that everything works. I just don't have a drive controller or bootstrap for this particular system to go any farther. It's a to-do.


Nope, my response was to Quantum II who posted today, who said in part:

Quantum II said:
The system does not work, and below is the last results from my tests:

I measured the voltages and they seem OK.
I cleaned the CCS CPU Card and replaced all the corroded jumpers. I reseated _every_ chip on the card and followed the manual in how to enable the built-in monitor.

No response over serial whatsoever. No garbage, no nothing. The LED's on the card does not light up, and if I put in the memory card, the LED on the memory card does not light up either..

If I put in the Cromemco DPU card things start to act a little different. The Memory card lights up, the floppy controller flashes it's "sel" LED and the two others are on solid. On the DPU card the "Z80" LED lights up.

Perhaps it would be better to split this thread off...
 

billdeg

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As far as I understood from the manual, the CPU card (The one I have) has a built-in monitor which can be "booted" by enabling Jump and selecting the monitors jump location by using the jump address jumpers.

What CPU card do you have ?


I have a JADE CPU. I don't think it has a monitor PROM, but I can re-check.

bd
 

QuantumII

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I have a JADE CPU. I don't think it has a monitor PROM, but I can re-check.

bd

My card is this one The California Computer Systems 2810 CPU.

Then we don't have the same CPU card. What other cards do you have in your system ?

I just ordered a logic probe off e*ay. This one actually. at $9.99 I think I'll give it a go :)
 
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billdeg

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http://vintagecomputer.net/browse_thread.cfm?id=31

I have been swapping cards in and out, but to tell you the truth other projects have bumped this one back a bit. I do want to get some sort of IO going, I have a bitstreamer II in this system.

What I need is a PROM with monitor that will work with the Bitstreamer II, any port. With more work I could probably get something going, but so far I have not got it to work yet.

Bill
 
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