inb300campbe@qut.edu.au (08/24/90)
Hello, I have been developing a debugger that I plan to install as a debugger in my boot-rom on my A1000 (only 8k out of 64k is used at the moment). In the process I have attempted to test it by booting it as a kickstart. It is now successfully running as a kickstart, but it took me a long time to figure out that sector $201 on the kickstart disk must remain identical to the normal kickstart disk. Sector $201 maps to location $ffff00. If I boot my debugger with sector $201 all zeros, then custom chip interrupts refuse to occur, but if I copy the sector from the 1.3 kickstart, the debugger runs fine. What is the significance of the page of memory at $ffff00? Are there some sort of control locations there? It isn't code anyway! Thanks. David Campbell inb300campbe@redgum.qut.edu.au
valentin@cbmvax.commodore.com (Valentin Pepelea) (09/05/90)
In article <14138.26d4fefc@qut.edu.au> inb300campbe@qut.edu.au writes: > > It is now successfully running as a kickstart, but it took me a long > time to figure out that sector $201 on the kickstart disk must > remain identical to the normal kickstart disk. Sector $201 maps > to location $ffff00. > > What is the significance of the page of memory at $ffff00? Are there > some sort of control locations there? It isn't code anyway! Indeed there is some data there crucial to the startup process. The length of the kickstart can quickly be recognized for example. Leaving the last 40 or so bytes intact should solve your problem. Valentin -- The Goddess of democracy? "The tyrants Name: Valentin Pepelea may distroy a statue, but they cannot Phone: (215) 431-9327 kill a god." UseNet: cbmvax!valentin@uunet.uu.net - Ancient Chinese Proverb Claimer: I not Commodore spokesman be