Apple I BASIC dump

[J Blaser]

>> Actually, I wrote some 6502 asm to bit bang out the game port
>> data, ttl rs232  ;-) . It isn't that hard.


> Did that to move Infocom game sectors from an Apple II to a C-64.
> It was a bit rough, but with both CPUs bit-banging away at 1200
> baud, it took a while.  In the end, though, the operation was a success.

Likewise, once did a similar thing to transfer a particularly interesting textual adventure game from an Apple II to an Atari 800.  Cobbled together a three-wire cable between game ports on each machine and used a very simplistic transfer method: Used one conductor as a single-bit DATA line, another for RCVR-READY, the last for signal ground.  We sent just one bit at a time, with the RCVR-READY basically ACKing each bit.  Certainly wasn't an efficient way to send data, but there was no reason to finesse it any more, since it was a one-time setup.

If I remember right, we figured that our 42KB transfer would take about 75 minutes.  After a slightly extended lunch, the transfer was complete.  I guess that works out to about 10 bytes per second!  With a few more minutes to patch the 'TTY-IN' and 'TTY-OUT' entry points, we had a fully working app.  If I remember correctly, we even figured out how to modify the game save functionality for the Atari, too.

- Jared