CompuServe Messages

Hi – " I'm new to CIS, and I've only had my Amiga for a week, so bear with me if I commit a faux pas or two. Thought I would start a bit of discussion about a posting by Bob Pariseau (CBM) that I got from the USENET Amiga topic. " While CBM may not have been at Comdex, Computer System Associates (CSA) was. They demo'ed an Amiga with one of their piggy-back boards installed. Just pull out your 68000, and plug in their board, and presto … you now have [are you ready for this?] a 68020 machine! The board also holds a 68881 Floating-Point chip, and 256K of RAM. WHAT a machine this is gonna be!!! BTW, it fits UNDER the FCC shield (gotta keep the Fed's happy). " Good news from CBM, too! Per Bob, Amiga V1.1 s/w will be compatible with the 68010 and 68020 processors. There ARE some things s/w developers need to do for compatibility reasons though. Bob mentioned: " 1. use the Exec GetCC() function to get the condition-code 2. NOT use the high order 8 bits of a pointer for unrelated data (the '020 uses all 32 bits for the address) 3. Exec maintains flags in the AttnFlags field of ExecBase to describe the processor type 4. if using the Supervisor() function, remember the stack frame is processor dependent; use the new SuperState() function for processor independent supervisor mode entry 5. V1.1 of ROMWack will correctly display info for 68010 and 68020 address and bus errors 6. the on-chip [256 byte] instruction cache is enabled on a cold start; keep this in mind if you write self-modifying code 7. the new Exec function TypeOfMem() should be used to find out if a given address is in Chip memory or Fast memory to insure compatibility with future Amiga architectures (rather than assuming that certain fixed addresses define the break between Chip and Fast memory) " All this support sorta makes you wonder what CBM has in the back rooms, doesn't it? [38 lines seems like a silly limit … go to part 2 posting]