anthony@convex.csd.uwm.edu (Anthony J Stieber) (06/16/91)
In article <1991Jun15.004351.11944@unlv.edu> elvis@jimi.cs.unlv.edu (Frederick Haab) writes: >There is a difference in the way 286 and 386 get memory (16 and 32 The 286 and the 386SX have 16 bit data busses, the 386DX and 486 chips have basicly 32 bit data busses. This is only a factor when designing motherboards and installing memory. The 16 bit bus machines will have to have at least 16 bits wide of RAM installed ( 2 SIMMS or 16 + 2 parity of DIP RAM), with similar needs for 32 bit bus machines. >bits? anybody?), a 386sx is a 386 processor in a 286 chip, which is >why they are slower then a 386dx (the normal 386), I believe you Sort of. A 386SX is a full 386DX, it has all the same 32 bit instructions and modes. The only difference is the data bus, since it's only 16 bits it makes it much easier to design a motherboard for it. It also has only a 24 bit address bus which can make it easier to design. The 386SX is not pin compatible with the 286 or with the 386DX , but there are little daughter boards that allow a 386SX to plug right into a 286 socket. >would have to get a 386sx, but there is also the matter of >changing the clock speed. For this type of upgrade I think you >would need an upgrade "kit" that takes care of all the little >things involved with changing processors as well as changing the >processor itself. BTW, a kit is still limited in memory access >as your system is now. Since the entire motherboard is being replaced, only the other boards installed in the machine could have clock problems. Usually, the slots are run at 8MHz, although this does vary, some machines have 12MHz and even higher speeds. The chances are pretty good that the 286 slots run at the same rate as the 386SX slots. If the new motherboard has a particularly high speed slots, the slots are generaly selectable between high and low speeds for compatibility. The old RAM may or may not work in the new motherboard, it depends. -- <-:(= Anthony Stieber anthony@csd4.csd.uwm.edu uwm!uwmcsd4!anthony Psion Mailing List subscriber submissions psion ----------\ the (human) moderator psion-owner -------+--@csd4.csd.uwm.edu subscriptions and file requests psion-request ----/