16 Dec
2001
16 Dec
'01
4:31 p.m.
ajp166 wrote:
PALS are 1970s technology, really old to some of us.
Arg! And here I thought the 8008 was 70's technology.
Actually thats not true. BY 1981 you have peripherals
in the 125ns read
write timing range. Then again Z80 at that time was just hinting at 6mhz
so z80 peripherals were of an according spped for that cpu. However,
other
parts were faster and often far cheaper.
If you must know it is a floppy disk controller I need. Right now
I plan to use WD2797 floppy disk controller. I would love to use
a newer chip,but I can't find any! I want to stay with DIP's and PLCC's
here. This may be the 21 century but my soldering skills are the 19'th.
Personally if I wanted the SIO functionality for a
NON-z80 system I'd
never use the zilog part. Reason it was not cheap,nor was it easy to
use for non-z80 systems. They were designed for the Z80, period.
Unfortunatly they were slow. If you wanted faster the 83xx or 85xx
parts from Zilog were a far better choice but Zbus was scary to most
people and they weren't cheap. The other part of this is NEC and
Intel did the MPSC (NEC D7201, INtel 8274) which was functionally
identical to the SIO and was "tuned" for 8080/8085/8088/8086 style
busses and faster as well. It was a more generic part than the SIO.
Also around that time Signetics and friends were doing the 2681 part
that was cheap and available in various flavors. Peripherals back then
were quite varied.
I still favor the simple dumb uart chip. TR1602?. I like things than
you hit reset, it starts ... not like the classic star-trek computers
that always
go down. Usually when you need them.
--
Ben Franchuk --- Pre-historic Cpu's --
www.jetnet.ab.ca/users/bfranchuk/index.html