Recent content by dansretropod

Hi All, Has anybody had any experience with these adapters: http://store.go4retro.com/6540-adapter/ I bought a couple for a 2001 PET but cannot seem to make them work. I have downloaded the character set ROM from zimmers "characters-1.901447-08.bin" and have used an eprom burner to put it...

Hi All, I've not done anything PET related for a while and have decided to try and sort out a none working 2001 chiclet PET. My first requirement is to find ROM images for all the 6540's in there. I looked on zimmers but couldn't see any chip numbers that match what I've got in the machine...

Hi all, Bit of a longshot this as I know this is a very rare computer but: Does anybody out there know how the keyboard on a Science of Cambridge MK14 is constructed? I purchased one recently and the keyboard seems to be missing the contacts that go into the "Circle Domes" mentioned in the...

Hi everyone, My chiclet PET had a lot of bad RAM that I've removed leaving it with about 1k that still works. Other than spending a lot of money on replacement RAM 6550 chips from ebay are there any other (cheaper) substitute chips I can use or modify to work in the original 6550 sockets? I...

Hi all, I'm in need of a replacement "-" key from my PET's chiclet keyboard which was purchased with it missing in action. This is a bit of a long shot, but if anyone has some spare chiclet keys they are selling or if anyone has some ideas for finding a replacement please let me know. Many thanks!

Hi All, I've been putting off repairing my 8296 for a while now so I thought it was about time I attempted to fix it. Connecting it up and powering on doesn't seem to do anything and looking at the circuit board there appears to be 2 components (C10 & R45) that are totally burnt out. Can...

Hi Everyone, Has anyone successfully connected a 4040 drive to a ZoomFloppy board? I have been trying without success. Typing in the command "cbmctrl detect" returns no devices. Thanks!

Hi Everyone, I was thinking of taking the pet video signal and making a composite adapter. Does anybody know the pinout for the 6-pin connector on the PET motherboard? I know these signals are available on the user port but would prefer to do it from the main motherboard connector. Many Thanks!

Hi, I recently got hold of a 64K expansion board for the PET, however it came with none of the cables need to hook it up:-(. Does anyone know if these cables or similar ones are sold anywhere online? The one that goes into the 6502 socket I'll probably have to knock together myself, but the...

Hi, I'm trying to repair a 3032 PET which has BASIC 2. I know the ROMS/screen RAM and from what I can tell the Main RAM work and would like to disassemble the BASIC 2 ROMs to try and trouble shoot the problems. My question is: Where does execution start when a 3032 BASIC 2 equipped PET is...

I've finally gotten some time to write some assembler to test the ram. I did a simple test to write the values 0-255 into the 1st 1k of ram 4 times. I then fill the rest of the 32k of ram with 0's. I then, in an infinite loop write out the first 1k of ram to screen ram and this is where I see...

Here's a pic of when I turn it on and manage to get something like a normal start-up screen, most of the time I get a blank screen, or, more usually a mostly blank screen with occasional random characters in various places. I'm going to try my hand at some assembler to see if I can see if...

Hi Everyone, I've got this 3032 PET that wont start up. When I turn it on I get the odd random character showing in random places, rather than a screen full of garbage. Sometimes I see the ### COMMODORE BASIC ### line, and then maybe a random character below. I've removed both 6520's as one...