Path: utzoo!dciem!nrcaer!scs!spl1!laidbak!att!chinet!mcdchg!michael From: michael@mcdchg.UUCP (Michael Bodine) Newsgroups: comp.sys.m68k Subject: Re: 68020 in a *68010* socket? Message-ID: <10123@mcdchg.UUCP> Date: 3 Jun 88 17:02:42 GMT Article-I.D.: mcdchg.10123 References: <17206@gatech.edu> Reply-To: michael@mcdchg.UUCP (Michael Bodine) Organization: Motorola Microcomputer, Schaumburg, IL Lines: 35 > I have seen all the talk about putting a 68020 in a 68000 socket, but is it > similarly possible to put a 68020 in a 68010 socket? What software problems > would be expected (as the priviledged opcodes on the '020 are also on the > '010, no?). As the 68000 and 68010 are pin compatible, there are no mechanical or electrical problems with using the same hardware in either socket. The 010 software is upward compatible with the 020, as opposed to the 000 which is MOSTLY upward compatible with the 020, so software gotchas should be fewer. Not to be construed as a commitment that there won't be any! > now this might be a really silly, but what are the prospects of putting a > 68030 in a 68000 (or '010 or '020) socket (with plenty of 32-bit RAM...) There are, in fact, internal ap notes and products from vendors like CSA which detail placing 030's in 020 sockets. I haven't seen anything that gives a design for an 030 into a 000 socket...although you COULD plug the 020 daughter board into the 000 socket and the 030 into the 020 socket on the daughter board. B-) A do-able thing. If you've lots of spare time and are in love with your soldering iron. By the time you were done, tho', you could probably go out and buy some small existing 030 hardware with lots less hassle and not much more money. Without a cache architecture for your local RAM, the performance enhancements seen with these kinds of add-ins are usually not that significant except for certain algorithms that run out of the on-chip cache. The limiting factor is the access path from the original socket to the original memory, which is usually far slower than the new chip wants to take it, so the new chip ends up starved for instructions most of the time. Still a fun exercise for the home-brew fanatic and a great learning experience for a designer. But the 030 comes in a 128 pin grid array package -- a lot of hair pulling to get that baby all wired up! Have fun... -- [ Michael Bodine, michael@mcdchg.UUCP Opinions expressed are mine and haven't ] [ been seen, commented on or in any way approved or even allowed by Motorola ] [ MicroComputer Division, Motorola General Systems Group or Motorola, Inc. ] [ No one else agrees with me; why should my employer? ]