Re: Question about Apple ][ ROM chips!

[az268@chebucto.ns.ca (Jonathan Adams)]

Charles Forbin (sark314@hotmail.com) wrote:
: I recently acquired two original ]['s.  The motherboard on one is
: copyright 1978 and starts in Applesoft BASIC even with the Language
: Card removed.  The motherboard ROM chips are also copyright 1978
: (there are tiny stickers on them).  I once read that the presence of a
: certain single pin in the upper right corner of this board makes it a
: "Revision 1" board, so I think that's what this is.  The handwritten
: number in the upper left corner is 8001.

: The second ]['s motherboard is copyright 1979 and looks slightly
: different from the other board.  There's a lot less green and more
: brown.  In the '78 motherboard, there were a few chips alongside the
: left side that each said "16K 16K 16K" (under the label "MEMORY
: SELECT"); they are not present here, nor does it look like there ever
: was a place for them.  The single pin I mentioned from the other board
: is also not here.  The number in the upper left is 8031.  I haven't
: tested this unit to see if it starts up in Applesoft without the
: Language Card.

: Basically, I'm trying to verify the authenticity of these machines.  I
: know that, on an original ][, one could access Applesoft from the
: Language or Firmware Cards, or load it from disk or cassette, but was
: it possible to physically replace the motherboard Integer BASIC ROM
: chips with Applesoft chips?  I'm also wondering what the chance is
: that either motherboard is in fact a ][+ motherboard.  I know the ][+
: was released in 1979, but does that mean its motherboards would only
: have copyright dates from '79 onward?

--
The board with the memory select blocks is an original ][. The ][ plus did
not have these blocks because they only came with 16K RAM chips. On the ][
you had the choice of using either 4K or 16K chips, but you needed these
special memory configuration blocks so the computer could tell what kind
of RAM chips you were using and where they were.

                                 R.I.P.
                    The Apple II series of computers
                               1977-1993 
.......................................................................