news@cit-vax.Caltech.Edu (Usenet netnews) (11/09/86)
Organization : Calfornia Institute of Technology Keywords: 68020, 68881 From: lyles@tybalt.caltech.edu (Lyle N. Scheer) Path: tybalt.caltech.edu!lyles A few questions. First, is it truely possible to use a 68020 replacing the 68000(ie, are there any problems, bugs, etc(I have a program that is said to make a 68010 work with the amiga, but I don't know if it will do the same thing with the 68020). Second, what is the relation of the 68881 to the 68020, and, if you can replace the 68000 with the 68020, is there a spot for the 68881? Wonko the Sane
dillon@CORY.BERKELEY.EDU (Matt Dillon) (11/09/86)
>A few questions. First, is it truely possible to use a 68020 replacing the >68000(ie, are there any problems, bugs, etc(I have a program that is said to >make a 68010 work with the amiga, but I don't know if it will do the same thing >with the 68020). Second, what is the relation of the 68881 to the 68020, and, >if you can replace the 68000 with the 68020, is there a spot for the 68881? > > Wonko the Sane Yes. However, many copyprotected programs will not work due to the fact that the idiots who devise the copy protection usually rely on timing of some sort. The 68010 is exactly a 68000 with some minor changes to allow virtual memory, plus a couple additional instructions. They also made an instruction which was unprotected on the 68000 protected on the 68010. The 68010 is only slightly faster than the 68000. I assume that most manufactorers of 68020 boards for the amiga would leave a slot for the 68881. The 68020 is a qantum leap from the 68010. Apart from being quite a bit faster and adding a couple more addressing modes, the 68020 has instructions to handle co-processors. The 68881 interface thus becomes trivial. With a 68000/68010, the co-processor interface must be done in software. -Matt