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Macintosh Classic II, FPU / Math Card (Picture)
- Thread starter uniserver
- Start date
Sure, sounds good. It’ll make a good project to show the SRCS in the new year. One slight hiccough in the plan, though — does anyone have a compatible 68882 to lend to the effort? I’ll be happy to mail it back afterwards (I have enough caution to solder to a socket, not the chip), but I haven’t any idea what clock speed or what version of the physical package I need. Most VLSI chips came in numerous package types and I’ve no idea where to look for information about it now that this decades-obsolete stuff is getting to be left behind by Freescale’s website. I’ll ask locally too, of course, but I do not anticipate anyone having one (there are few if any Motorola hardware hackers at our meetings just now).
Bah, that’s what I get for posting before doing my homework. Turns out the things are only $6 each on Fleabay (with $2 sockets) and any that was ever sold will work just fine in a Classic II, what with its feeble 16MHz bus (no 68882s slower than that were ever sold). The only thing to watch is that if I ever do up a proper design and turn these things into a saleable product I need to stay away from the FN-marked PLCC version. It isn’t lead-free-standards compliant.
I will keep you all posted on my progress. Do not expect great rapidity.
I will keep you all posted on my progress. Do not expect great rapidity.
Do you have one yet?
Shipping is a bit prohibitive from/to Canada but I can dredge one up and send if need be.
Shipping is a bit prohibitive from/to Canada but I can dredge one up and send if need be.
...A bit off topic for the 'FPU card' side of it, but AFAIK the expansion slot on the Classic II also handles the external ROM slot as well (up to 1MB IIRC).
If you're designing a board at all, why not include the potential future ROM upgrades by including a ROM socket as well?
I'd love to see a "IIsi" style ROM for the CII in the future...
If you're designing a board at all, why not include the potential future ROM upgrades by including a ROM socket as well?
I'd love to see a "IIsi" style ROM for the CII in the future...
It’s actually 2–3 MiB, varying according to a jumper on the motherboard. The Classic II can have up to 4 megs of ROM, and the jumper determines whether 1 or 2 of those megabytes are on the motherboard.
Well, yes, that’s exactly what I’m working towards. See earlier posts in this thread.If you're designing a board at all, why not include the potential future ROM upgrades by including a ROM socket as well?
I'd love to see a "IIsi" style ROM for the CII in the future...
Alas, I haven’t had a whisper. And while I am grateful to you for volunteering to lend one of yours, I agree that Canuckistani postal rates are prohibitively expensive. I don’t know the detailed fee schedule but it’d likely be more expensive even than buying one from a US source on Fleabay and putting my address as the destination.
One thing I can say is that any 68882 at all will work — the FN-marked ones may be a problem to resell in a finished product due to RoHS rules, but that hardly matters for a prototype.
