Posted By
JamesC
on 2004-04-21
20:51:27
|  Re: Wizard Castle demo for the C64, 128 and Plus/4...now available!
Paul,
If I were programming it, I would copy the character set from ROM to RAM but keep it at the same memory location.... then drop the top of BASIC down to protect it. (Or drop BASIC down and then move the characters, actually this would be wiser.)
10 POKE 55,208 : POKE 56,0 : CLR :REM DROP BASIC DOWN TO 53247
20 POKE 1177,62 : REM ALLOW PEEK TO SEE CHARACTER ROM
30 FOR I = 53248 TO 55295 : POKE I, PEEK(I) : NEXT : REM COPY CHARACTERS TO RAM
40 POKE 1177,63 : REM RESTORE PEEK'S NORMAL FUNCTION
50 POKE 65298, PEEK(65298) AND 251 : REM TED SEES RAM-BASED CHARSET
60 ** REDEFINE YOUR CHARACTERS, ETC**
...
190 POKE65298, PEEK(65298) OR 4 : REM TED SEES ROM-BASED CHARSET
By doing this, yes we do lose 11.25k of RAM, however if you need to store additional data like rooms visited, money on hand, items, etc you have the RAM from 55296 to 64767 available to POKE and PEEK your data to and from.
WARNING The 264 series will go nuts if you do any string manipulation while POKE 1177,62 is in effect! This is why I recommend that you turn it "on" and "off" only as it is needed.
James C, www.cbm264.com
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