[sdiy] Re: PCSYNTH Web Page Up

[Helen Austin]

On 6/8/05, Scott Gravenhorst <music.maker at gte.net> wrote:
> There is also an explanation as to why I designed an 8 bit memory cycle ISA
> card instead of a 16 bit memory cycle ISA card.

Just a quick comment. You plan to decode the addresses so that
$B8000 and $B8002 are the low and high byte of the DAC. Why not decode
them so that $B8000 is the low byte and $B8001 is the high? That way
you can use a single 16-bit MOV to write to the DAC; the ISA bus
management should translate them automagically. Then the code
becomes shorter, and you can get more of it into the CPU's cache.
(It also becomes simpler and more direct to write.)

Helen (following this thread avidly!)