Recent content by QuillOmega0

I'm revisting my Kaypro 10 after I shelved it after this ugly issue reared it's head. I can't read or write the hard disk drive. Well I can but it doesn't work and crashes the mfm emulator after a while. This was a working condition previously but now it doesn't work. I ran the diagnostics...

I'm having the same issue for sure but if I reorientate the card now it seems to be okay for a bit. So maybe an MFM drive cable got broken before. Not likely but I've had that happen on my Mac.

Confirmed this was the fix. Now the WD1002 card is causing a fit. Cold it seems to be okay but the second it gets warm to any degree it'll refuse to write to the virtual MFM drive when it had no issue before

I'm looking for a replacement Kaypro 10 HDD Controller Preferably from an '83 system if that makes a difference

So in the grand item of fixing the Kaypro 10. The HDD Controller or a related subsystem is having an issue. I know for a fact it's not the HDD itself because It's an MFM emulator that had zero issue when I did the initial replacement. Now I'm getting NID errors and looking at the emulator logs...

Replacing the Baud Chip did fix this.

After I fixed the issue causing it to lock up a new issue reared it's ugly head. The serial port has stopped functioning and I'm unable to communicate using a null modem cable to another computer when it was working before. I've tried all variations of cables and a smart modem using the...

New 6545A-1 is installed. So far no lockups so I'm cautiously optimistic.

I ordered a 6545 which I hope is going to be good cause those are hard to come by. If this doesn't fix it I don't know what to do beyond pulling the board apart and doing a rebuild from scratch

The 6545 also runs HOT, almost too hot to touch. I don't know if this is by design or not. I ordered what I hope is a spare but is there any way I can jump it out so the CPU isn't waiting on it (despite not having a monitor)

I think you have it here. The CPU can execute ram up to the point where it starts talking to the controller then it locks up. Sometimes if I'm lucky after a while on the garbled display, the CPU will slowly have it clear (line by line) and it'll boot or lock up halfway displaying the ROM...

I'm stumped. I've reseated everything. Same symptoms persist. Reset. Does not clear the display when the system locks up.

I agree, I found my non display was due to an issue with the CPU socket, I fixed it and confirmed it's back to the old symptoms. I've replaced the Z80 as well with no change.

Thanks Larry, If I pull U36, will that allow the CPU to execute code from the ROM? Even if the display is blank? Anyway now I'm not getting any display at all on boot so I need to go through from scratch. At this point I may just say screw it and get a new board and give this board to someone...

I pulled the cpu and checked pin 34 which is the A4 address line and that does look active But hard for me to tell Voltages on pins 40-30 are as follows without the CPU: A10 - 40: .7V A9 - 39: .7V A8 - 38: .7V A7 - 37: 1.5V A6 - 36: 1.5V A5 - 35: 1.5V A4 - 34: 2V A3 - 33: 2V A2 - 32: 2V A1 -...