CompuServe Messages

#1MegChipRam??

    29-Mar-90 01:02:29
Sb: #95897-#1MegChipRam??
Fm: Scot 76004,3246
To: Betty Clay/SYSOP 76702,337
Betty, I've gotten a chance to look at some of the service manuals for the A500 and it indeed looks like they are capable of supporting 1 meg of chip ram. There is one jumper (JP2 on rev 5 motherboard) that needs to be moved when the 1meg Agnus is installed, and that look's like about it! The fat Agnus chip already accesses 1 meg of ram, but the blitter and everything else will only get to the first 512k. The jumper changes the 512k of err… The jumper moves the 512k of expansion memory from location $c00000 to location $80000 making 1 meg of contiguous ram starting from $000000. The super fat Agnus can then use this as 1 meg of chip ram. -Scot