This is a very important point with old logic analyzers. The prices can look very affordable, but without all the cables, pods and flying lead sets, they are useless.
I did not know this. Thanks for the info.
My version of WinCUPL only runs on very old Windows like W98 or 32 bit versions of XP and use RS 232. Is this OK for you?
It's good to find a person who can still program the PLS100/82S100 part. This was the first Programmable Logic Device on the market back in the mid 1970's.
I have a Data I/O 29B Programmer with the 303A-001 Signetics Programming Adapter. I also have the 303A-101 Signetics H & L Design Adapter...
Hi Philip,
Nice to hear from you. I'm impressed you have keep that old Pet working for so long. I remember when you, MikeS and I (plus others) fixed that PET so many many years ago. You took many great scope photos that really helped us find the usual problem (flaky NAND gate?). Looks like you...
Daver, no, as Hugo says, it is a BRK (B*) to the Monitor. If /diag was held Low, it would perform a Call to the Monitor. The Program Counter is sometimes in low RAM and sometimes at $Dxxx.I would guess bad ROM or bad zero page RAM.
Yes, the video board by the PET can pass the 21VDC through its full wave rectifier with minor voltage drop and drive the the voltage regulator chip which outputs the required +18VDC.
See Video board schematic http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/8032/321448.gif
That top ROM is stamped 6540-014 and is from a BASIC 1 set and the chip goes into socket H6. Here is the info on that part:
H6 901439-06 6540-014 ROM Basic 1 D800-DFFF
And note that there are no way to know that this 45 year old part is still working unless it was recently tested.
Perhaps the MAXv2 firmware has been corrupted. Did you try to reload it?
It used to be somewhat difficult task requiring an Atmel programmer, but he has added code to do this within his gadget.
Of course you may be wary of doing this since the .prg files are working right now, and if the boot...
If the signal Graphic is stable, then the VIA source is OK. It may be the character generator ROM itself. Can you replace it with a programmed 2816 EEPROM? You want to use the 2K bin file characters-2.901447-10.bin from this page...
It may also not have the original RAM and ROM chip sets. You would have to look inside to see if it has a RAM/ROM replacement board plugged into the CPU socket.
It would be fully functional with a replacement RAM/ROM board and maybe even more reliable, but not worth the top money to a collector...