[sdiy] My New Project - PCSYNTH

[David Cornutt]

On Jun 6, 2005, at 10:05 AM, Scott Gravenhorst wrote:

> I really like Roman's idea of hacking off and using the edge connector 
> of
> a defunct ISA card, stick a 16 bit latch on it and go with memory 
> mapped
> I/O to the DAC.  A simple, fast mov will load the DAC.  That would make
> this thing scream (except for the two "in" instructions required to 
> get a
> MIDI byte, but that's only 3 uS instead of 9).

OK, I'm showing my age here, but I recall that the port instructions 
were
painfully slow even back in the 8080 days.  I worked on a project circa
1982 that was built around 8085s, and that system had most of its
I/O devices in memory space because IN and OUT were too slow.