18 Dec
2001
18 Dec
'01
12:01 p.m.
Richard Erlacher wrote:
There's nothing to tweak, since it's
all-digital, and, eventually, but not this
week, I can probably send you a scan or a PDF of the datasheet. The original I
have is a preliminary, but I might still have a datasheet from the ChipCenter or
Freetradezone. What I really like is that there is no need at all for cable
drivers, since the interface lines are intended for direct connection. All you
have to do is synchronize your CPU/DMAC to the data acquisition loop and then
roll. If you're slow, you may want to use wait-states, but if you have no
dificulty getting around a 13.5 microsecond loop (the first pass only) and 16
microseconds per byte, then you're in.
Having looked at a few other Floppy disk datasheets for the pc, I would
suspect
it needs a 24 Mhz clock. I can divide this by 2 to give me 12 Mhz clock
for the
CPU - 333 ns memory cycle. If I stick with the WD part I will run the
cpu @ 16
Mhz (250 ns memory cycle) and divide by 16 for the floppy clock. One
advantage
of WD part is that I can find source code from SS-50 bus computers to
help
with software development.
--
Ben Franchuk --- Pre-historic Cpu's --
www.jetnet.ab.ca/users/bfranchuk/index.html