Re: Notes on Cleaning and Repairing an Apple II Plus

[dog_cow@macgui.com (D Finnigan)]

Michael J. Mahon wrote:
>> 
>> Something gave me a strong impression that I do not have a Revision 7
>> board,
>> and that was the presence of three 16k memory select blocks. I'm guessing
>> that it's revision 6 or something, because it has the single wire-wrap
>> video
>> pin, as well as the color-killer transistor. And it also has all of the
>> chips to the right of the 6502 CPU. The copyright date below the 6502 is
>> 1978. Unfortunately, I can't check the motherboard part number at the
>> moment, so that will have to wait.
> 
> Bingo.
> 
> It is definitely pre-rev 7.  You can either use the proto area in the
> lower right corner of the board (slots on top) to wire up the enhanced
> color burst gating that was pre-installed on the rev 7 board, 

I did more reading, and it looks like there wasn't a rev 6, but my board may
well be a revision 3. The description matched mine: 16k memory select blocks
that are not soldered down. Mine were removable.

Apple II/IIplus production dates by spacealbum:
Rev. 3 board 820-0001-03 silkscreened under the CPU, CPU has to be
removed to see it, handwritten numbers on the boards are production
dates, used from 78?? until 7930 (=30th week of 1979), memory select
blocks can be removed, lowest Apple serial number I have seen is
A2S1-14282, highest A2S1-31907, maybe very early IIplus models used
this board as well.

My board looks like this one:
http://i158.photobucket.com/albums/t118/bradandjennifer_2007/80251-1.jpg

Ack, I need to get back to that Apple so I can say for sure what it is.
Unfortunately, it's been put away (there's no room for it here; put it
away!).

> or you
> can try a different color monitor, hoping for one that is less sensitive
> to color burst leakage.
> 
> Or you can use a monochrome monitor wired directly to the video output
> jack and ignore the color monitor when using text modes.  (That was my
> standard mode of operation).
> 

I'm still using the color television set in the living room that's about 10
years old. I haven't got a dedicated monitor yet. :-(

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