conklin@msudoc.ee.mich-state.edu (Terry Conklin) (07/30/87)
I posted this to the net some time ago but never saw a response, and am not certain it ever got out. Is anyone aware of an upgrade 68020 chip that comes in a custom socket so it can be plugged in to a 68010 system? All over the docs it says that the 68020 is a "proper superset" of the 68010, which in my dictionary should mean it's software transparent/compatible. Also, it refers to the dynamic bus sizing capabilities of the 68020. It would SEEM that by tying the proper ~DSACKx line you could teach the 68020 to be a 16bit cpu for the purposes of replacing a 68010. I'm really looking for an already existent upgrade along this line, but if it's not possible (hah) (let's try "feasible") I'd be interested to know why. Terry Conklin ihnp4!msudoc!conklin conklin@cps.msu.edu (517) 372-3131 3/12/24
ford@crash.CTS.COM (Michael Ditto) (08/07/87)
In article <17@nancy.UUCP> conklin@msudoc.UUCP writes: >Is anyone aware of an upgrade 68020 chip that comes in a custom socket >so it can be plugged in to a 68010 system? All over the docs it says >that the 68020 is a "proper superset" of the 68010, which in my >dictionary should mean it's software transparent/compatible. Also, it >refers to the dynamic bus sizing capabilities of the 68020. It would >SEEM that by tying the proper ~DSACKx line you could teach the 68020 to >be a 16bit cpu for the purposes of replacing a 68010. Computer System Associates, Inc. makes a piggyback board that plugs into a 68000 or 68010 socket and holds a 68020 and, optionally, a 68881 floating point coprocessor. They even make them in a variety of shapes and sizes to fit in whatever space you have around your CPU slot. Note that the operating system may require some slight changes to deal with the '020. Also, the '020's instruction cache is not active on reset; it is a good idea to turn it on. Their smallest boards are just the two PGA sockets and three PALs, plus the 64-pin plug sticking out the other side of the PC board. I beleive they sell the boards with or without one or both 68XXX chips installed. They can be contacted at: CSA (Computer System Associates, Inc.) 7564 Trade St., San Diego, CA 92121 Contact Patricia Chouinard (619) 566-3911 I have not extensively used any of their products, but I have seen them demonstrated. They also make a very nice (and expensive) 32-bit expansion chassis for the Amiga with the 68020, 68881, and 32-bit static ram. It cooks. -- Michael "Ford" Ditto -=] Ford [=- P.O. Box 1721 ford@crash.CTS.COM Bonita, CA 92002 ford%oz@prep.mit.ai.edu