Re: Problems! Disk ][ drive just whirs and whirs; IIc monitor knob stuck; IIe enhanced not...

[mdj <mdj.mdj@gmail.com>]

On Apr 29, 9:53 pm, Larry Stedman <sted...@binghamton.edu> wrote:
> Motherboards on the 2 unenhanced are both 1982
> with a number 820-0064-B   (Or is the last 8?  Maybe B given Matt's info
> about revision A.  )  There is also a number underneath that in white:
> 607-0164-M on one and the other lacks the letter.

Note that there was the later edition of the IIe motherbard fitted to
the platinum IIe's. This one also ends in "A" even though it's really
revision "C" :-) Sorry I don't have the part numbers handy

They're easily distinguished though - they have a single "CF" ROM
instead of a pair, and use 2 64kx4 DRAM chips instead of 8 64kx1's

> The enhanced is from 1984.

An enhanced 1984 board would have been shipped unenhanced originall
and had an upgrade kit fitted.

> I tried comparing them to see I could spot the board differences--they
> look identical!  Then realized from David's comment that it's not that 4
> new, *extra* chips were added-- just the electronic innards of the chips
> that were changed.  I had thought I could spot a CPU chip that would be
> marked 6502 or 65C02---would have been too easy!

The boards are silk-screened so it should be clear, but there's only 3
potential parts that can be the CPU (The other two being the MMU and
IOU HALS). From memory, the CPU socket on US rev A and B boards is in
the lower left quandrant near the Auxiliary slot.

> Is there an easy way to tell if these unenhanced have the 65C02 and/or
> the newer character generator ROM?    IIRC, one can run certain programs
> that use MouseText to check the character stuff.

A quick way is to boot the latest system disk which has the latest
ProDOS version 2.0.3 on it. 2.0.3 requires a 65C02 and will issue a

*** RELOCATION/CONFIGURATION ERROR ***

If one is not present.

> The 1988 plantinum IIe with a numeric keypad must have been a lot
> wider... but sounds cool.

No, they're the same size, the keyboard takes up the whole case width,
and it's (IMHO) the finest keyboard ever offered on an Apple II.

Good Luck with it all :-)

Matt