Macintosh Classic II, FPU / Math Card (Picture)

[uniserver]

Posting this only because i have never seen one yet, until now.

 

[mcdermd]

Oooh - very nice! Any pictures of the other side?

 

[uniserver]

nope just the one picture

 

[bbraun]

May as well link the source.

 

[uniserver]

I'm not going to lie, The little kid in me wants that all for my self, that is why i did not post the ebay link.

I think my 2 year old is rubbing off on me ;-)

 

[uniserver]

by the way, the seller is a cool dude.

He shot a pic of the rear for me

 

[mcdermd]

Well that is interestingly simple, no?

 

[Macdrone]

With a classic memory module an fpu and some time could you recreate it?

 

[uniserver]

2 caps, some wire wrap, and a FPU and one could re create it.

interestingly simple, Yes.

 

[Macdrone]

So ill send you a memory and fpu and you can make it happen after you buy it?

 

[uniserver]

haha, i dunno

 

[uniserver]

from the seller, Info on the 2 caps on there.

One side reads K5M the other reads 104

 

[uniserver]

A little info on those caps.

http://www.picaxeforum.co.uk/showthread.php?15901-K5M-104-Capacitor-Polarity

104 is indeed .1uF as Premelec

 

[MinerAl]

Still need to know what's going on under the chip, and the connector.

Buy it and dissect it!

 

[uniserver]

Some bidder sniped it and won it for a dollar over my max bid.

My max bid was 41 bucks. I did not want to pay over that,

I already have the wire wrap, I have those caps in-stock, I have a 16mhz FPU.

I will solder the wires right to the header on the motherboard.

maybe get a little hobby pcb from the shack, to set the FPU on.

I don't have the time to do this now, but it appears less complicated then the InternalHardDriveinaPluShAcK™lol

 

[bbraun]

FWIW, the ClassicII dev note has the pinout of the connector. It's pretty much just directly throwing the 68882 on the bus, with the only trick being the 16 bit bus, so doubling up the data lines and using the /DSACK 0 & 1 signals.

I've put some labels on those pictures, to illustrate. For the most part, the labeling refers to the 68882 pins, not necessarily the Classic2's connector. For instance, D16 on the Classic2's connector goes to D0 on the 68882, and I've labeled it D0:





You can also put a ROM in that socket, up to 3MB worth.

 

[uniserver]

you are the F'in man!

 

[MinerAl]

You can also put a ROM in that socket, up to 3MB worth.

So, you could put a little 7.x boot image in ROM and do the Classic trick in a Classic II?

 

[bbraun]

I'm really not sure about that. I haven't looked at the ClassicII ROM in particular. There's a good chance it has the EDisk driver, which is what the Classic used to boot (also RAM disk driver, and pcmcia flash card in laptops). That driver looks over some set of addresses (I don't recall how it determines that), for a valid header. So, it might be possible you could put a valid EDisk driver's ROM disk image into ROM there and have it automagically bootable.