Recent content by Nivag Swerdna

Someone has asked me to make up a characters-2.901447-10.bin 6540 ROM for them... ... this got me thinking! When I bought my PET 2001-8 back a few years ago it had an original ROM and I never thought much about it... looking at my notes it says MOS / MPS 6540 / 010 2678A which I worked out...

I had a project recently where I had to interconnect a daughter board with a PCB... The only reliable solution I could get involved machine pin headers on the daughterboard and replacing the sockets on the main PCB with machined round sockets l.

I haven't had time to look at this properly... but I looked at it improperly... Put a 6502 back in the CPU socket; PETTESTER in H7 and... I wonder if that is a clue?

I've taken all the above onboard; just need to find some time to experiment... will probably be the weekend. Thanks all. PS Please don't mention the discolouration in the top left... it's a huge embarrassment! That was in my early days of hot air for chip removal.

Wow! I've read that document so many times and never noticed that! My brain must interpret it as 05! http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/2001/2001_main_logic_assembly.pdf

Revisited... Physical pressure doesn't seem to help. Damp finger is in my diagnostics kit. Yeap moved finger around. Seems most effective near pin 27. When I have time I will whip the PCB out and look for issues. This poor motherboard is used for every gadget I have made so there has been...

The different naming conventions are confusing... but yeap... the very original Basic1 complete with lots of bugs. (Obviously the PETTESTER runs don't verify the contents of H7 since that's where it sits)

So my beloved PET has started to act strange... which is rather annoying as I'm trying to test some bits and pieces before sending them out to people... It won't reliably start unless I put my finger on pin 27 of the CPU... If I leave my finger there it performs perfectly. Could this be a...

B Sockets - Not recognised rom-1-c000.901439-01.bin 0xe85f 0x0 0xe85f rom-1-c800.901439-05.bin 0xe4fe 0x0 0xe4fe rom-1-d800.901439-06.bin 0x1e49 0x0 0x1e49 rom-1-d000.901439-02.bin 0x31fc 0x0 0x31fc rom-1-e000.901439-03.bin 0xca92 0x0 0xca92 rom-1-f000.901439-04.bin 0xf21c 0x0 0xf21c...

FWIW... and mostly for @daver2 's benefit... copies of my bodged versions and source...

Hi. I did do a bit of poetic licence and sent you the version that goes in H7. It should say put in H7 on the label ;) Can you remove the Tynemouth board, just put it in H7 and have a 6502 in the CPU socket. And send a photo of what you have set up. It really shouldn't look like what you...

http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/8032/8032029-01.gif Indeed... a simple reset circuit. Strange goings on can be many things... RAM, ROM, .... etc... Probably the best approach would be to burn @daver2 's PETTESTER and give your PET a workout.

On my way to the post box. :)

Well I should have warmed up the soldering iron so I could put @rglenn 's ROM in the post but I couldn't resist a small hack of the PETTESTER source... ROM Top line is original sums... next line should be a sum of only the first 2K... in the E case they match since only 2K of E is summed first...

@daver2 Is V5 ready? 2K Checksums would be nice here!