jdg@elmgate.UUCP (Jeff Gortatowsky) (08/10/87)
I hope someone at Motorola or Commodore can help me with this.....
First. I have a XC68020RC12 and an MC68881RC12A. What does that mean?
Umm... what I mean is, is XC a bad omen? The 881 seems to be a production
version.
The mask (or version, or whatever) on the 020 is 2A23G8512. On the '881
the mask is 1A93N8626. Are these good parts? Will they function together?
I once heard a rumor (fact?) that early versions of the 020 wouldn't play
with the 881 and had barrel shifter bugs. True? False?
Ok,ok, what's the point? I'd like to take the two (020 & 881) and put them
on a proto board and replace the '010 in my Amiga with them (at 7.16mhz).
A). Can anyone give me a schematic for doing this?
B). Is my CPU any good? If not what's it's problem? Can I 'trade' it
in on a 'good' one? What's 'XC' mean? Xperimental?
I got the 881 as a sample. The 020 through a co-worker Any help out there?
--
Jeff Gortatowsky {seismo,allegra}!rochester!kodak!elmgate!jdg
Eastman Kodak Company
These comments are mine alone and not Eastman Kodak's. How's that for a
simple and complete disclaimer? grr@cbmvax.UUCP (George Robbins) (08/10/87)
In article <704@elmgate.UUCP> jdg@aurora.UUCP (Jeff Gortatowsky) writes: > I hope someone at Motorola or Commodore can help me with this..... > > First. I have a XC68020RC12 and an MC68881RC12A. What does that mean? > Umm... what I mean is, is XC a bad omen? The 881 seems to be a production > version. The XC indicates that the part is an engineering or pre-production sample. Typically, there is an errata sheet associated with the mask level that documents thing that do not work correctly or timing differences from the official specifications. It may work fine in your application, or may not. > Ok,ok, what's the point? I'd like to take the two (020 & 881) and put them > on a proto board and replace the '010 in my Amiga with them (at 7.16mhz). > A). Can anyone give me a schematic for doing this? > B). Is my CPU any good? If not what's it's problem? Can I 'trade' it > in on a 'good' one? What's 'XC' mean? Xperimental? Well, CSA has apparently has a couple of boards, one at 7 MHz and one at 14 MHz that would do what you want, although they're probably a bit pricy. There was mention here of a board from Europe that might work also. The origen of most of this stuff is a Motorola applications note that describes how to make a 68020 look like a 68000. Contact you local Motorola office for a copy. -- George Robbins - now working for, uucp: {ihnp4|seismo|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@seismo.css.GOV Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
stever@videovax.Tek.COM (Steven E. Rice, P.E.) (08/10/87)
In article <704@elmgate.UUCP>, Jeff Gortatowsky (jdg@aurora.UUCP) writes: > I hope someone at Motorola or Commodore can help me with this..... Will someone at Tektronix do? > First. I have a XC68020RC12 and an MC68881RC12A. What does that mean? > Umm... what I mean is, is XC a bad omen? The 881 seems to be a production > version. > > The mask (or version, or whatever) on the 020 is 2A23G8512. On the '881 > the mask is 1A93N8626. Are these good parts? Will they function together? > I once heard a rumor (fact?) that early versions of the 020 wouldn't play > with the 881 and had barrel shifter bugs. True? False? The first five characters of the string are the mask level, and the last four are the production date. The 68881 is good -- it is mask revision 1A93N, built week 26 (end of June) of 1986. The 68020 is probably a dead loss -- it is mask revision 2A23J, built week 12 (end of March) of 1985. We have some old 0A45J mask 68020s dated 8517 (five weeks after your 68020). The 0A45J mask was still pretty buggy. The 68020s we are currently receiving are the 2A70 mask revision. Incidentally, the minimum clock spec for the 68020 (including the 12.5 MHz version) is 8 MHz. I assume they will in fact run at 7.16 MHz, but it certainly isn't guaranteed! Steve Rice ----------------------------------------------------------------------------- new: stever@videovax.tv.Tek.com old: {decvax | hplabs | ihnp4 | uw-beaver | cae780}!tektronix!videovax!stever