16 Dec
2001
16 Dec
'01
12:45 p.m.
"Peter C. Wallace" wrote:
On Sun, 16 Dec 2001, Richard Erlacher wrote:
I never heard about pal's until about 1990. In some ways the peripheral
chips are in a really sorry shape. You have vintage slow I/O (2 MHZ?)
or PC motherboard chip sets. Nothing in between. On my FPGA I can run
with a 250 ns memory cycle, but need to stretch it to 625 ns for I/O.
--
Ben Franchuk --- Pre-historic Cpu's --
www.jetnet.ab.ca/users/bfranchuk/index.html
I disagree that it's a mess. I haven't
looked at the requirements for a Z80
peripheral since the early '80's, but I can assure you that I'd dispose of
any
1st year engineering intern who couldn't whip up a suitable PAL or equivalent
MSI/SSI logic to handle the generation of properly timed inputs to the thing in
an hour or less.
Sure its trivial to do now but we were talking 1981 when PALS were
expensive.