euamts@eua.ericsson.se (Mats Henricson) (12/05/90)
Hi!
I just read MacUser and MacWorld and noticed that the discontinued macs
(i.e. Plus, SE, CX, X) all have 256k ROM:s, while allmost all the remaining
machines have 512k ROM:s. It could be a pure coincidence, but something
tells me that it isn't.
So, what I wonder is if someone out there knows what extra there is
in these 512k ROM:s. (Of couse SOME people know, but will they tell me :-).
Mats Henriksson / euamts@eua.ericsson.sesteveh@tasman.cc.utas.edu.au (Steven Howell) (12/17/90)
euamts@eua.ericsson.se (Mats Henricson) writes: >Hi! >I just read MacUser and MacWorld and noticed that the discontinued macs >(i.e. Plus, SE, CX, X) all have 256k ROM:s, while allmost all the remaining >machines have 512k ROM:s. It could be a pure coincidence, but something >tells me that it isn't. > So, what I wonder is if someone out there knows what extra there is >in these 512k ROM:s. (Of couse SOME people know, but will they tell me :-). >Mats Henriksson / euamts@eua.ericsson.se I have managed to locate the address, data and chip enable lines of the mac ROMs. They are encoded in 16 bit and are quite complicared, but basically the roms conatin additional routines that enable better interupts,better problem (Or Bomb) handling capabilities ad prediction logic of faults. I have not finished going thru these roms as they appear to be shifted in somr locations, I will post my results (Not the ROM contents, this is copyrighted stuff)but the general operation routines of the IWM, serial and so on, Must fly, optical network installation awaits me!. Uni Of Tas.... Steve h e