[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: 200 apple II clones confirmed

David Wilson wrote:

Michael J. Mahon wrote:


Eric wrote:


When I was in Korea 1984-1986 I saw dozens of locally-made clones. They
were all variations of the II+, and some of them used 64K RAM chips. I
think they all used off-the-shelf parts, which is why it was harder for
them to clone the IIe (I didn't see any IIe clones while I was there).


Within Apple, the use of ASICs in the //e was seen as a powerful
deterrent to the cloning that had plagued the ][ and ][+.



It didn't work...

My first Apple II compatible computer was the MPF-III (model 312) which
is a IIe clone made from LSTTL and two PAL chips (plus a
microcontroller in the detached keyboard). The MPF-III model 327 was
subsequently released and it did use MMU and IOU ASICs.


As a2aviator confirmed, the chips were not clones, but "excess
production" sold out the back door by a chip house that manufactured
them.


The model 312 was only about 95% software compatible with the IIe.
Replacing the ROMs with genuine IIe firmware bought it up to 99% with
the following differences:


Hard to see why they would shrink from copying the ROMs after they'd
illegally used the ASICs!


* 2KB aux RAM confused ProDOS which was expecting 0KB, 1KB or 64KB only
* The AUXZP softswitch was not implemented (as there was no Aux slot).

I built a 64KB aux ram daughtercard and replaced one PAL with a larger
GAL with AUXZP support added giving me a superset of the IIe.


Very cool.

-michael

New, faster SUDOKU v2.0 solver for Apple II's!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."