19 Dec
2001
19 Dec
'01
8:59 a.m.
From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca>
But then I find 6800/6809 code more readable than
"You Know Who"
I kinda figured that. Just like I prefer Z80 opcodes to 8080 as they
are more regular in format.
This will be simple polled loop with interrupts
disabled regardless
of what chip I use. I would love to have had DMA but I
ran out resources
for it. In fact DMA is rather messy as I don't tri-state the address bus
Polled loop has speed requirements and the problem of what to do
if the FDC never sees dat and has to error out.
and would have to stop the CPU for a free memory cycle.
If I was
doing this on a I/O card I most likely would have a sector buffer
their rather than dma.
The last design I did that way save for ram was cheap by then so
I did a full track buffer.
Allison