 Author's Notes | This program was written while creating the first SID card. It was in my computer's ROM, which was a battery powered SRAM. When the battery died, the program was lost (so how it made to Plus/4 World I have no idea, though I do have some guesses).
Needless to say, this is also an unfinished piece of software, but there are some interesting things in it:
- In order to avoid conflict with any music or player routine, this whole software is in the $D000 - $DFFF memory area. (On the C64, this is used for I/O van, so mostly likely no music uses it.)
- It does not use zero page at all, again to avoid any conflict with musics/players. Instead of saving/restoring zero page addresses, they aren't touched at all (which in turn means there's a lot of self-modifying code).
- The program cannot load from disk, only from tape, because at the time I did not have a disk drive yet. From tape, it only loads stuff which has been saved a specific way. It uses one of the tape turbos (possibly Tape Messias, but this is not for sure), but the KERNAL header is not saved. Therefore without this program those files cannot be loaded back. Somewhere I have 2 60 minute tapes full of tunes, which could be loaded back (if I had a usable datasette). |
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