That's right. It gets confusing because there are two sets of meanings for the designations A, B, & C. In one context those letters reveal not the size but rather the function of the battery. Regarding function, Wikipedia says, "Each battery had a different designation depending on which vacuum tube element it was associated with." Thus, A would designate a filament supply, B a plate supply, and C a grid (ie; bias) supply.

But in the more usual context A, B and C are among the many designations which do indicate the physical size (not the function). Wikipedia lists those sizes here.

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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html

This is the large, 1.5V dry cell that got me started in electronics, as my 3rd-grade teacher did experiments with us using it, along with an electric bell, knife switch, light bulbs, and electromagnets:


For the wikipedia article, I could send them a picture of the Eveready #413 30V battery they're missing. I have one in front of me, from an old VOM. I have no idea how old it is, but it still has not leaked. The cross-section is almost identical to that of a 9V battery, except the corners are not quite as square. This picture shows it next to an old AA, against a quadrille pad with 1/4" squares:

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

I found a source for brand new No. 6 dry cells a while back. I can't recall what it was though. I posted it on another forum; if I run across it, I'll post it here.

A few years ago, I disassembled a receiver which had a "C" (bias) battery in it. It was in the form of a zinc-carbon Eveready AA cell, soldered under the chassis. That cell was at least forty years old and for some reason still provided enough bias (and hadn't leaked) to cause the amplifier circuit to still work. That "C battery" outlasted the paper condenser coupling the amplifier input.

The battery I can't find any trace of anymore was a 12V battery that looked exactly like a common 9V battery except a little flatter but wider, if memory serves. When I was a teenager in my electronics experimenting years, I would see them for sale at a local Ace hardware. I couldn't justify buying one. I seem to remember they were rather pricey. I also seem to remember it was a mercury battery. I do recall asking someone what they were for at the time, but can't recall the answer.

One should note that the green fuzz indicates some battery leakage.
Don't be fooled.
Dwight

Well, I pulled that battery out and I can promise you the battery did not leak.

However, most of the electrolytic caps DID leak. The greatest concentration of green fuzz is around each cap.

I don't know if I will ever be able to clean it.

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Cat; the other white meat.

They use a borate solution. White vinegar is right there as well.
The caps should of coarse be replaced.
Dwight

I've replaced the caps but I'm not very happy with my work (and it didn't fix the Mac). So I will re-do them.

Do you have any information on the borate or vinegar solution?

Thanks

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Cat; the other white meat.

I think you misunderstand. The capacitors leak a borate solution.
Use white vinegar to clean it. Use care, undiluted vinegar can burn.

Now you also get to try and dig up a schematic for the board, and check connectivity of each trace in the affected areas. I ended up soldering wire-wrap wire in to replace a broken trace on my IIfx when I recapped it.

Please don't tell me that! LOL

Yeah, I know...you're right. I actually have the schematics.

One thing I hate is that because of the compact design, I have to slide the board back into the case to power it up. I wished I had an extension cable for the molex connector on that thing so that I could just power the board up with it on the bench.

If I keep restoring these classic Macs, I may make one.

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Cat; the other white meat.