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ADC Super Six software

I think the sawtooth waves are truly there. The scope and probe are designed for 500MHZ and I am probing a 800KHz signal. I am an amateur so I will check and make sure I have my coupling set correct. I am also grounding the probe to the voltage regulator which maybe I should be ground directly to the chip's ground pin. I have an older Tek scope but it has some problems. The CRT lights up for maybe 10 seconds and then slowly fades away. turning it off and letting sit for a few minutes and turning it back on it repeats the same problem.
I think the sawtooths are coming from a bad chip but I have not come across the right situation to pin point it. There are (2) 74ls245's that I am planning on replacing when the new chips arrive. I am also attributing the 'working but won't boot floppy' issue with the resistor network that I snipped because of how warm it was getting. I think this was the pull-ups for the floppy cable. I have a replacement for that in the mail too.
I am still feeling like the sawtooth waves are part of the dram refresh the way the are there between the normal activity of the lines. Just a hunch which may be pointing me in the wrong direction.
Once I replace the 245's and resistor network I will do more testing and report what I find.
Right now my projection is to start replacing chips and brute force with parts.
 
I got one of my Super Six boards working tonight. The second one doesn't display anything, so I'll work on that after I get back from Tandy Assembly. I'll also try to get the ADC HDC working.

I've got both the CP/M 2.2 and CP/M Plus images posted here working. Does anyone have the TurboDOS images? I'd like to give that a try next.
 
I pulled the images from the link you sent. HxC is what I usually use and it converted the images for me.
 
I am still working on my ADC super Six. I replaced some ICs, Removed all the ICs off the board. Not sure if anything helped. The board is in its original condition of will run for a few minutes and then has problems. I wanted to update this post because I don't think the machine is locking up, but maybe the serial comms to the machine stop working. I am wondering if it is how the interrupt chain is set up. If I try to initialize the PIO, the machine exhibits the problem of working but not repsonding.
STAT LST:=LPT:
and then try to print
TYPE mytext.doc <ctrl>+P
That messes the system up. Every time. I know the PIO uses the CTC so it could be that too.
Either the machine goes into a tight loop, or the serial stops responding. Sometimes after it hangs I get cold boot errors, or BDOS bad sector errors. I have even seen the track selector on my Gotek go to 226 tracks! So I think the machine is running but not in a usable way.
The machine seems fine if a program keeps running. Like MEMTEST will run forever. I can type in ED but as soon as a stop for more than a few seconds that machine screws up.
Even if you let it sit at the command prompt for more than 15 seconds it will start having problems - first the line feed does not work, or control characters - just letter on the screen in bottom line.
Any suggestions on where I should be looking would be great.
 
What baud rate are you running on your terminal ? I always use 9600 8N1 on any of my S100 systems including my ADC S6. Higher rates just seems to invite problems.

Larry G
 
9600 8N1 is what I am using. I agree with you that anything above that baud causes problems. Not just in this but 9600 is a safe bet for most hardware. I am working on making a test program for the PIO. I don't think it is the PIO itself (I have replaced it with no change) but will maybe help understand the problem. I bought a Z80 assembly book that has the PIO and has some code for running LEDs off the parallel port. I want to test the CTC and DMA also to see if I can narrow down where the fault is coming from.
It is possible an interrupt is hanging the system I guess.
 
Could someone with a Super Six SBC verify some chips for me:
U67, U72, U73
Are these supposed to all be 74LS373? The parts list shows U67 as a 74LS374 and does not list U72.
The schematic shows them all as 373's.
And to something else that maybe someone could chime in on: I am using the SBC with a Jade Bus probe. When I use the rest button on the machine, the data bits slowly turn off (like if someone was walking room to room in a house turning lights off one by one). You would think when you hit the reset the data bus would instantly go dead, but it takes about 2-3 seconds for all of the bits to clear. Is this normal? I also noticed on the bus probe that bits 2 and 4 are always lit. Normally when you boot the data bits all flash on and off. Not bit 2 and 4. They might be pulsing too fast for my eye to see it but you can see all the other bits pulse but not 2 and 4.
Any wisdom would be great.
Thanks for all of the help. I know I would not be able to accomplish this stuff if I didn't have people to ask questions to. Sometimes just asking is enough to help me solve it (rubber ducky method)
 
Just checked mine. U67 = 74LS374, U72 and U73 are both 74LS373.
I don't currently have my ADC boards in a chassis. I have 3 chassis but nothing to spare at the moment.

Larry G
 
The original chip I pulled from U67 was a 374 but had its ground pin broke off. Somehow I stuck a 373 in its place, probably going off of the schematic. I replaced it with a different 374. No changes.
Also in my post above I mentioned the data bus problem. It's actually the address bus.
Sometimes it does seem to go in a tight loop, sometimes it will give me a 'COLD BOOT LOADER ERROR DD'. Not sure why it is going for a cold boot.
Booting CP/M 3 using banked memory makes the parity light go on. Could it be bad memory? memtest doesn't find errors in the user area of ram. I have not tested below 100H.
The machine almost always boots. sometimes it acts dead but using the rest button gets it going. When it is running programs it runs fine. It's when it gets to idle is when it has problems. Could it be a tri-state latch that is sticking instead of floating on the address bus? the backplane being used is not terminated - but the SBC is the only board on the bus (besides the Jade bus probe).
Could it be that sometimes it gets a bad address on the address bus? can a Z80 tolerate something like that? I would assume it's an all or nothing sort of thing, the code on the buses has to be perfect or it will not work.
Why does the machine lock when I try to print (or give the cold boot loader error)? I checked the IEI and IEO pins on the PIO and the interrupts seem to be doing their thing.
Some ramblings. Thanks for listening.
 
Looking through the source code *.MAC files on the floppy I am booting from. They all mention being source for the Super Quad. Could I be running the wrong setup for the Super Six? I am using the images from bitsavers. How different is the Super Quad from the Super Six?
Super Six Source Code
 
Just skimming thru document files it seems the first difference is the Super 6 can do 6MHz but the Super Quad cannot. I think I told you my Super Six was unstable at 6 so kept it at 4.
The other difference I found is several comments about changes in floppy drivers. Here is a comment from Don Maslin himself mentioning paged memory:

"Advanced Digital Corporation had their facilities in Huntington Beach CA.
While I haven't checked recently, the last I heard they were still in
business, but now in the PC area. Subsequent to the Super Quad that you
have, they came out with a Super 6 that ran at 6mhz, vice 4, and carried
128k of paged memory. The two boards were generally software compatible,
with some exceptions. If you are unable to obtain docs from ADC, I can
make copies of docs that I have at moderate cost."

I would think paged memory was increased in the Super Six because the slower disk i/o couldn't keep up.
TurboDOS had a different floppy driver module for the Six vs Quad.

Larry G
 
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