jacobus Posted July 5, 2017 Share Posted July 5, 2017 This problem is really driving me nuts. I can only assume I am missing something really stupid and obvious, but I sick and tired of banging my head against it… What is the standard “correct/failsafe/easy” way to activate the upper 16K bank or RAM on an XL ? I’ve been trying to do this within Quick and keep running into a brick wall. I use Quick’s copy command BMOVE(Source,Dest,Length) to copy the ROM to a safe place in memory, then I turn off interrupts (via NMIEN=0 and IRQEN=0) and then disable ROM by setting bit 0 of PORTB to 0. Then I copy the ROM code back to its proper location. At some point during this operation the system crashes – with the ROM only partially restored. BMOVE($C000,$600,$1000) BMOVE($D800,$1600,$2800) EOR(PORTB,1,C) NMIEN=0 IRQEN=0 PORTB=C BMOVE($600,$C000,$1000) BMOVE($1600,$D800,$2800) What the heck am I doing wrong??? Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.