Running Unexpanded Games with 16k

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randolph.pickle
Vic 20 Amateur
Posts: 55
Joined: Thu Nov 27, 2014 10:50 am

Running Unexpanded Games with 16k

Post by randolph.pickle »

Assuming I have a 16k RAM cartridge plugged into my VIC, is there a way I can rearrange memory so that I can run games made for the unexpanded VIC without removing the cartridge. I know that the start of BASIC, screen, and color memory get moved when the VIC is expanded to 16k. I was wondering though if there was a way to change these without removing the cartridge.
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Mike
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Re: Running Unexpanded Games with 16k

Post by Mike »

Enter the line: POKE642,16:POKE644,30:POKE648,30:SYS64818 at the start-up message.

As shorthand here's a small program, which does the same: (download). Put it on a convenient place and run it with LOAD"3K.PRG",8,1.

The VIC-20 will then reset and show you 3583 BYTES FREE with BASIC start and end, and screen at the same addresses as for an unexpanded VIC-20. This change remains in effect until the power cycle or hard reset.

I have integrated this program into my "Unexpanded type-in Games Collection" (see here), so you just load the first program on disk, and run all games from a menu, regardless whether a RAM expansion is plugged in or not.
Boray
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Re: Running Unexpanded Games with 16k

Post by Boray »

This menu will detect what memory configuration the program you try to start requires and downgrade to unexpanded automatically if needed and then run the program:
http://www.boray.se/commodore/vicmenu.html
PRG Starter - a VICE helper / Vic Software (Boray Gammon, SD2IEC music player, Vic Disk Menu, Tribbles, Mega Omega, How Many 8K etc.)
randolph.pickle
Vic 20 Amateur
Posts: 55
Joined: Thu Nov 27, 2014 10:50 am

Re: Running Unexpanded Games with 16k

Post by randolph.pickle »

Awesome! Thanks for the information guys. :D
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