Macintosh Slice - a Pre-release Color Classic

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David Cook

Tinkerer
Jul 20, 2023
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I just picked up a pre-release Color Classic. Notice that it is missing the word "Macintosh" beneath the Apple logo, the words "Color Classic" on the bottom plastic insert, and the QuickTime sticker on the lower right. The plastic has not yellowed.

Macintosh Slice Color Classic.jpg


Looking closer, there are no signs that the text was removed.

Unlabeled.jpg


On the back, some large stickers were removed. Could have been "Property of Apple" and "Not FCC certified".

Large stickers removed.jpg


Underneath, the model information is not molded into the plastic.

No molded information.jpg


It was manufactured in November 1992, which isn't incredibly early compared to the February 1993 release date. I assume Apple manufactured production units in volume months before making the product available.

Manufactured November 1992.jpg


The motherboard is revision 820-0367-02.

Slice motherboard 820-0367-02.jpg


The EPROMs have handwritten labels with "slice" (the codename for the Color Classic). Connector J11 is installed for ROM programming, as are transistors Q3 (2N2907) and Q2. However, J12 (ROM SIMM slot) is not installed.

Slice EPROMs.jpg


Here are the markings on Q2

Q2 transistor 1AMe.jpg


The CUDEA is labeled v2.35 09/25/92 0607F9. CUDA reset S1 is installed.

There has been significant leakage on the CUDA as well as the first several pins on the video memory slot (lower left). I cleaned all of this up during recapping.

CUDA 2.35 09-25-92.jpg


There is an 'oops' component on the back of the PDS slot.

Oops.jpg


I recapped the motherboard and hand cleaned it. I didn't want to lose labels in the ultrasonic cleaner. The motherboard works. Unfortunately, the analog board does not work -- despite looking very clean and low mileage.

A dump of the ROMs shows they match the production release. The hard drive was repurposed by an ordinary user in 1993/1994 for Ham Radio and Spanish language practice. Despite running an unerase on the hard disk, no signs of source code or development enablers exists.

In any case, a nice little piece of Macintosh history.

- David
 

David Cook

Tinkerer
Jul 20, 2023
176
235
43
A couple of things I forgot on my original post.
1. Someone added an FPU. That's nice.
2. But, they only added two 1 MB sticks of memory. Why not at least 2 MB sticks?
 

dougg3

Tinkerer
Jan 10, 2022
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www.downtowndougbrown.com
What a cool find! Congrats, and thanks for sharing! It's cool to see the extra components mounted for in-system ROM flashing.

I have a theory about the "oops" component on the bottom of the board. Based on the L42 marking, I think it's a BAT54A pair of Schottky diodes. Looking at the close-up picture, I think it's across pins C32 and B32 of the PDS connector, which are -5V and GND respectively.

I also notice your board differs from a stock CC board in that it doesn't have diode D2 (it would be between the sound chip U5 and the 68030). D2 would be a Schottky diode across -5V and GND. So I think that's the bodge they did before they added it on the top side of the board.
 
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