Hello Steve,

I had a Commodore VIC20 at the time, and I remember I once fried a 6522 PIO chip in it by a poke command. There was a (original Commodore) data cassette recorder connected to it and one of the I/O lines of the chip was hooked up to the "play" switch which was at the other side hard wired to ground. I loaded a program from tape and forgot to press "stop" when it has done. I poked around to the pio chip (the chip its I/O lines were connected to the user port to, at which I had connected a project I was experimenting with), and the I/O line connected to the switch in the recorder was blown. so no more "play" key detection was the consequence. I had the VIC 20 schematic and repaired it myself, because the PIO was on a socket and the 6522 was not a custom chip, it was easily available. To prevent the same damage in the future I mounted a resistor in the datarecorder, between the switch and GND.

I can say to Aka I have learned a lot with the VIC 20, it was my first real computer and the first computer I learned assembly code with (6502),because I wanted more control over the hardware :-)
At the same time I had an Atari 2600 gamecomputer which had a 6507, a stripped down version of the 6502. Had one gamecartridge modified, the 4k ROM replaced by 2 x 6116 (2k x 8) low power RAM chips with back up battery. Via a self made adapter I plugged a 2600 cartridge of a friend to the VIC 20 and saved the ROM contents to casette tape. So I was able to put the game later in the modified "RAM"cartridge and play the game on the 2600 when I wanted. I also disassembled some cartridges to learn more about the inner workings of the 2600. Some things stayed mistery at that time, other things get clear. That was almost 20 years ago I think. Nowadays we have internet and if someone does a search on Atari 2600 he will find loads of information, not available at that time.
My knowledge about 6502 did help me a lot to understand the working of the 8051 some time later....

Sorry for be-ing a bit OFF-topic, but I sometimes want to tell something about those good old days too...you know the feeling, don't you Aka? ;-)

Henk