trc (03/24/83)
I have my Commodore 64, but havent gotten my programmer's reference manual yet. Could someone provide me with the answers to the following? (1) Where does the extra RAM switch in at? The cartridge ROM? How is this done? The system specs say there is 20K of ROM - where? (I guess I want a memory map.) The specs say there is 52K for ML use - what is the other 12K? (2) Where are the two 6522's located in memory? (3) Is there any way to get two full pages of hires (Bit mapped) graphics that doesnt overlay the zero-page and stack? (For animation purposes.) Also, is there a ROM character set at the end of the first page? I tried poking there and saw no change in what appeared to be the full two character sets. (4) I noticed that there is a soft but audible pop when the volume is changed on the sound chip - is there any way to avoid that? (5) Is there a character map for the hires display, or are the characters in a fixed order that cant be changed? (Not the character set. I want to know if it is possible to change the contents of a character area by changing the character code in a manner similar to the text page. I understand that this is possible with the 6560 in the VIC20.) (6) What do the un-explained bits in the graphics table do? What is ECM? (I've figured out Bit Mapped Mode, I think.) Tom Craver houti!trc American Bell, Inc, Holmdel NJ