Re: VIC-20 "all games in one" cartridge update

From: Marko Mäkelä (
Date: 2001-04-01 14:04:49

On Fri, 30 Mar 2001, Larry Anderson wrote:

> Have ypou tried contacting the folks behind the Vectrex, Atari 2600 or
> Intellivision multi-carts yet?  Many use dip switch selection for the
> bank of the EPROM to be visible, others are more sophisticated with
> power-up menus...

This one will be even more sophisticated.  For the 2600, it is reasonable
to store uncompressed ROM images to the ROM, aligned at bank boundaries,
since most games are 4k.  (There is no read/write line on the Atari VCS
2600 cartridge port, but some games use custom bank-switching schemes,
activated by accessing certain addresses in certain order.)

There are so many different switchable memory blocks on the VIC-20 that
the bank-switching logic for the ROM would either be very complicated, or
limited to certain memory configurations, or waste large amounts of memory
for each game.  This design stores compressed (PuCrunched) games to the
ROM, and the menu software (stored in the default ROM bank) takes care of
decompressing the games to RAM.  The cartridge will be disabled from the
memory space when the games are running.  I've already written the menu
software; see <URL:> for an earlier
version.  The current version autodetects PAL/NTSC.


This message was sent through the cbm-hackers mailing list.
To unsubscribe: echo unsubscribe | mail

Archive generated by hypermail 2.1.1.