Re: Question about Apple ][ ROM chips!

[Wayne Stewart <waynes@intergate.bc.ca>]

Charles Forbin 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.

Given the date, it almost guaranteed to have been a II+. I believe it
should
likely be a Rev 4 board. If so then above the 6502, between slots 3 & 4
should be the word REV and in the hole at the bottom of slot 4 should
be the number 4. Also in the Rev 4 all the 16K memory select blocks
are soldered in and not removable. If I'm wrong on that, then pull out
the 6502 and under it will be the revision number. That doesn't apply
to the boards with 1979 copyrights. It's at least two years too late to
be a Rev 1.

> 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.

On the second board at the feft side of the motherboard should be a set
of
numbers over the Apple 1979.  Something like 820-0044. Whatever they are
will identify the revision.

> 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?

Many people replaced the Integer basic ROMs with Applesoft ones.  One
ROM set or the other could be placed in any II or II+ board. The
copyright
dates were only copright dates and didn't differentiate the II or II+.
The II+
came out when the boards with the 1978 copyright were still being made.
Since both your boards were made in 1980, there's almost no chance they
were ever anything but a II+.

    Wayne