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I found the critical question!



david@uow.edu.au (David Wilson) wrote in message news:<3b95bcf5$1@news.uow.edu.au>...

> The only difference between an Apple ][ and an Apple ][+ is the ROMs.
> 
> If it has Integer BASIC and the old Monitor it is a ][.
> If it has Applesoft BASIC and the Autostart monitor it is a ][+.
> Look for the Microsoft & Apple copyrights on the Applesoft ROMs.

I think I should set about this with the intention of *disproving*
that it's an original ][.  It's conceivable that someone replaced all
the original motherboard ROMs with Autostart and Applesoft, so now I
have to make sure that the board itself couldn't have been placed in
original ][ systems.  Since the meaning of the handwritten number in
the upper left corner of the motherboard is still apparently up for
debate in this thread, I turn to the revision #'s of the board:
 
> Non-RFI - p/n 820-0001-XX (found under 6502 socket on early revs, near F1 later)
> 
> 00	no aux video pin, 3x RAM size selector blocks
> 01-06	aux video pin, 3x RAM size selector blocks
> 07	aux video pin, no RAM size selector blocks
> 
> RFI - p/n 820-0044-XX (near F1)
> 
> A-D	just minor changes to improve RFI

The number under the 6502 on the '78 board is 820-0001-04, so I guess
that means it's a Revision 4.  The question then, is whether or not
Revision 4 boards were ever used in original ][s.  If the answer is
no, then it's a ][+ board; if yes, then I need something else to help
me pin down whether it's a ][ or ][+ board (unless there is absolutely
no difference between Rev 4 boards in the two machines [ROM chips
aside], meaning I'll never know).

Incidentally, I just visited
http://ground.ecn.uiowa.edu/apple2/MiscInfo/Hardware/IIpart.revisions
-- is this person right in identifying a Rev 4 board with an original
][?