ROM hot swapping

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Ryan Roth

Dec 16, 2023, 12:12:27 PM12/16/23
to PAL 6502 computer
I figured I should share more of the things I am working on.

I was working on porting Adventure to my PAL-1, but due to the size of all the data, I got stuck. My workaround was to burn it to a ROM. Being it was too big for the 32K ROM, I burned it to a 64K ROM, and added a boot loader that copies the lower 32K of the ROM to RAM, prompts you to switch to the upper 32K of the ROM, and then jumps to the program there :)

Hans Otten

Dec 17, 2023, 12:45:47 PM12/17/23
to PAL 6502 computer
That looks impressive! How did you port this from where?

Ryan Roth

Dec 17, 2023, 3:57:19 PM12/17/23
to PAL 6502 computer
"Porting" was being generous. I grabbed a copy of the Fortran source, copied all the text strings from it, and then with a game map and the original source, I implemented it in 6502 asm. It is incomplete, as I lost momentum. Also, I made a typo in my first post, should have been upper/lower 16K of the 32K ROM, not 64K ROM. I attached a copy of the ROM image if anyone wants to mess with it.

Neil Andretti

Dec 18, 2023, 6:56:29 AM12/18/23
to PAL 6502 computer
Hi Andre,
Don't hide your light under a bushel! This is a veryimplressive use of the RAM / ROM. Congrats.
I've already build a 48K ROM Card, so I would be happy to see the sources on github ;)

Ryan Roth

Dec 18, 2023, 10:39:23 AM12/18/23
to PAL 6502 computer
Here is a link to the code
It has some of the original Pascal files in there too.  This is my first real project in assembly, so it may be ugly :)


Dec 18, 2023, 7:01:40 PM12/18/23
to Ryan Roth, PAL 6502 computer
Thanks for sharing another impressive job ;)

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