Re: ALF 8088 co processor board

[pausch@saaf.se (Paul Schlyter)]

In article <370265cd.0106110759.214b1eb1@posting.google.com>,
Rich J. <aiiadict@hotmail.com> wrote:
 
> I have what appears to be an 8088 coprocessor board.
> 
> It has the processor, some ROM chips, and a few logic
> chips on it.  I don't see any RAM on it
 
The ALF 8088 board had one ROM chip -- those other chips which appear
to be ROM chips are actually RAM chips.  AFAIR the ALF 8088 board
came with one RAM chip of 2K, expandable to 8K on-board.
 
> so I assume it uses the A2 memory
 
It does so too: since the 8088 is able to address 1 MB of memory, you
can think of it as having 16 "Banks" of 64K each, where one of the 64K
banks is the Apple II memory.
 
> It has a 4 pin connector on the top.
> 
> Does anyone have a manual, software drivers, or
> other information about this card?
> 
> How can I start it up, and make it execute code?
 
I may still have my ALF 8088 documentation and diskette left.  It
contained very little software though -- mostly a patched RAM version
of Applesoft where the 8088 did the floating-point math and thus
speeded it up by approximately a factor of 10.  There were some
utilities too, plus info on how to make the 8088 execute your own
8088 code.  But there was NO software development tools at all on
that disk - not even an assembler.
 
Some extras you once could buy to the ALF 8088 board was: an add-on
board where you could put 128K of RAM plus an 8087 numeric
coprocessor (I suspect actually doing so would put some strain on the
Apple II power supply though), and MS-DOS 1.0 on floppy.  If you
wanted to run MS-DOS on your Apple II though, you had one big problem:
how to obtain MS-DOS software on Apple II disks..... in principle
this was the same problem Apple CP/M users had; however there was a
lot of CP/M software available on Apple II disks, but I don't remember
having seen ANY MS-DOS software ever on Apple II disks.
 
The ALF 8088 board was advertised as "the board IBM don't want you
to buy".  Yes it WAS faster - slightly faster - than the 8088 in
the IBM PC: the ALF 8088 ran at 5 MHz while the original IBM PC
ran at "only" 4.77 MHz.  That 5% speed difference would hardly be
noticeable at all unless you timed it with a clock.  Also the Apple II
RAM was probably slower than the IBM PC RAM, so if the ALF 8088
accessed the Apple II memory a lot, it probably ended up running
slower than the IBM PC.
 
Apart from the Applesoft speedup the ALF 8088 was mostly a curiosity:
interesting for those who wanted to acquaint themselves with the
8088 but apart from that not of much use.
 
-- 
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Paul Schlyter,  Swedish Amateur Astronomer's Society (SAAF)
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