DPickett@HIS-PHOENIX-MULTICS.ARPA (07/22/86)
Actually, with its dynamic bus sizing and cache, it is simple to make a board with some 32 bit memory (optional but desirable) and a 68020 to replace the 68000 directly. The 68020 can detect that the memory is only 16 or 8 bit as it selects it, and use more cycles if necessary for the data being accessed. This makes it the most drop-in-able of 32 bit micros, it could go into the 800xl or such, and address all the little guy's memory and peripherals as part of its address range. It should be an addin, not a followon only.
jdg@elmgate.UUCP (Jeff Gortatowsky) (07/24/86)
In article <860722125056.438578@HIS-PHOENIX-MULTICS.ARPA>, DPickett@HIS-PHOENIX-MULTICS.ARPA writes: > > Actually, with its dynamic bus sizing and cache, it is simple to > make a board with some 32 bit memory (optional but desirable) and a > 68020 to replace the 68000 directly. Of course almost any CPU can replace any other if the proper hardware glue is installed. The much larger problem is handling the kernel level problems. As I'm sure your aware the stack frames generated by the 68020 (and 010) are not all together compatible. The kernel has to look at the stored format number or it's a gone'r. -- Jeff Gortatowsky {allegra,seismo}!rochester!kodak!elmgate!jdg Eastman Kodak Company <Kodak won't be responsible for the above comments, only those below>