DEBRO Posted March 26, 2002 Share Posted March 26, 2002 Here's the deal. In the 5200 Tempest disassembly Keithen is setting $C000 - $C007 to #$00 every time he clears the P/M Graphics pages. I originally thought this was put in to crash the 8-bit but I'm not really sure about this. I know locations $C000 and $C001 hold a check sum (LSB/MSB) for ROM bytes on the XL/XE but what about the 400/800? These locations aren't used right? I so then what purpose would it serve to set these locations to #$00? Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 26, 2002 Share Posted March 26, 2002 Aren't these pm registers in the 5200? i.e. $D000 on the computer = $C000 on the 5200. Quote Link to comment Share on other sites More sharing options...
Nukey Shay Posted March 26, 2002 Share Posted March 26, 2002 Yep, here's an equate table. (400/800 at top, 5200 at center) http://www.azstarnet.com/~jeffryj/equates.txt Address $C000-$C007 = Horizontal positions of players/missiles Quote Link to comment Share on other sites More sharing options...
DEBRO Posted March 26, 2002 Author Share Posted March 26, 2002 Well I guess that would explain it. No wonder it's done after he clears the P/M graphics. Doh!!! Quote Link to comment Share on other sites More sharing options...
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