This add-in card for the Apple II is rather interesting:
- adds a 1MHz 6809
- shares memory with the 6502
- runs some code approx 2x faster
- can run FLEX or OS-9 or a PASCAL accelerator
- steals approx 80% of clock cycles from the 6502
- can cause the 6502 to lose state and malfunction, if the instruction mix contains too few dead cycles

More info:
http://www.hackzapple.com/ORG1/M2/COPROC/6809MILL.HTM



See also the McMill which did the same with a 68008
http://www.hackzapple.com/ORG1/M2/COPROC/68008MILL.HTM

There was another 6809 board from West-Germany, the IBS AP10:



This 6809 has its own 64kB RAM. Means that the 6502 runs parallel with full speed.

IBS developped some other coprocessor boards, i.e. the AP20 (68000) or AP21 (6511).


Please, it's OS-9 There is no relationship to Half-OS from IBM.


The 65C02 should solve this problem.

Regards, Ralf

Oh, that's more like it! 64k RAM could be expensive though, in say 1983 - any idea what price this card would have been?

Let me fix up my OS-9 error...
... although I should note that it's OS/9 in the manual.

I just have a copy of a pricelist published in August 1985. Nothing else They offered the AP10 for 895DM as "AP10 INTENEX 6809-64k mit Pascal" but I don't know what's the meaning of "with Pascal". There is no explanation. In 1985: 2.94DM were US$ 1.00.


Microware, the company behind OS-9, wrote it OS-9. I know that even resellers and developers wrote it wrong.

Regards, Ralf

P.S.: the pricelist

Put that in a Mimic System's Spartan and you'll have three computers in one.

A quick look at a Jameco add from June 1983 shows 4164-150ns going for $7.95 each or 8 for $59.00

The Commodore 64 was advertised in the same Byte magazine for $289 and the Atari 1200 for $449

So it wouldn't have been super cheap, but not outrageously priced.