Colour Classic Logic Board Revelation

[Scott Baret]

I don't know if this is a known fact or not, let me know if it is, but I found this fascinating.

My old CC had one of the Rayovac 4.5V batteries on the logic board. One of the new ones I got on Friday has a 3.6V half-AA battery! I've never seen that in a CC before. The manufacture on that one is February 1993 as opposed to my other CCs which are both summer 1993.

Anyone else familiar with this oddity?

 

[equill]

And conversely, I've never seen a CC with a 4.5V alkaline battery on board. I am intimately familiar with five CCs, two of which are Performa 250s, but all are 1993 (Apr., May, Sep., Oct.), and all have provision for the usual half-AA 3.6V lithium. So also did the fifth, which now lives with Kallikak. The only significant variation that I have seen is the presence (not just the solder pads) of a CUDA switch on one of mine.

The nominal lifetime of the CC was Feb. '93 to May '94, which gives the 4.5-V variant a lifetime of about two months, at most.

de

 

[Scott Baret]

Interesting, because the CC I have with a 4.5V battery is July 1993, older than two of your 3.6Vs. The one thing I haven't checked is the place of manufacture on those CCs, maybe there were two suppliers and one did it differently?

 

[equill]

All CCs that I have seen begin their 'serial' numbers with SG, but that's not to rule out that more than one logic board manufacturer could have been involved. That is certainly the case in other Mac models. There are differences in colour (tan or green) in CC MLBs, and closer attention may reveal other differences than those of the CUDA switch and battery type.

I misinterpreted you as having written that the early one carried the 4.5V batt., and it therefore appears that use of 4.5V was a middlish period occurrence. A strange departure from the norm that was in all Compact AIOs after the initial use of cylindrical 4.5V batteries in Macintosh to Plus.

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[beachycove]

Is it a genuine CC board or could it maybe be an LC550 board in a CC case? Or indeed, a CCII board?

Certainly the LC575 board used for the Mystic hack requires a 4.5v cell, and these others might also.

 

[Scott Baret]

I'd assume it's a regular CC board since I got it from a school and I doubt they'd do much with it there. I'll have to check.

 

[equill]

My first response to the post was, "A 575 board, perhaps?", but I dismissed that with the further thought that just the difference in size between a 68040 and a 68030 would be a dead giveaway. Was my faith in you misplaced?

A 550 MLB in a CC would be a sneakier form of masquerade, having both 68030 and 3.6V lithium battery, but it would not have provoked the speculation about 4.5V alkaline batteries. Most definitive of all will be the part number of the MLB.

de

 

[LCGuy]

Its still easy to check if its a 550 board - the stock CC board has a 16 Mhz MC68030, and IIRC, looks slightly like an LCII motherboard (which makes sense, since its based on the LCII). The 550, on the other hand, has an extended LC PDS slot, and a 72 pin SIMM slot instead of 2 30 pin SIMM slots, and shares its design with the LCIII.

Either way, thats a curious find...never heard of a CC with a 4.5V battery before.

 

[beachycove]

Here's an odd turn-up. I found this while looking at 3.6v 1/2AA batteries on ebay (seller mdbattery):

"The Color Classic, Macintosh LC 520, and LC/Performa 550 early production logic boards used this battery. They were later revised to use the 4.5v Alkaline Square battery. Check your Mac to determine which battery is used."

 

[equill]

Odd, indeed. It implies, perhaps, that one of two or more MLB-suppliers used (and it would have needed redesign, however slight, of the board) the 4.5V battery from as early as July '93 (as recorded by Scott), and that lithium and alkaline batteries were simultaneously in use at least until Oct. '93, if not until May '94.

Stuart Bell may well be aware of this difference, and it may even have been raised in the CC forum moderated by him within the 'Fritter forums, although I don't recall that as having happened while I was following the CC forum.

de

 

[beachycove]

It is indeed a CC: see http://docs.info.apple.com/article.html?artnum=11751 which has some CCs alongside some 520s and 550s using 4.5v Alkalines.