RE: BASIC and System ROM replacements

Hallo JG, 


> Something I'd find useful is being able to have more than 16K
> available in the 16K cartridge slot, and to be able to page
> the cartridge out. Then I could copy greater than 16K code
> from the cartridge to RAM, than page out the cartridge.

A 27512 EPROM can handle 64 KB. A 74LS273, a resetable latch, can handle the pages plus 'paging out' the cartridge. 
After a reset the C64 'sees' the cartridge and starts executing its program. The first thing the program does is copying the actual copy part into RAM and executing it. At the end of the bank the program sets the 273 to another value and start copying the next bank. This is repeated until the whole program is copied. The last thing left to do is setting a bit of the 273 that disables the cartridge.


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