13 Dec
2005
13 Dec
'05
10:05 p.m.
Allison wrote:
I sure a Xylinx mumblefrap with all the right goop
could get you
that. However with 8k srams, 8keproms and a amazingly small
handfull of parts.. As drawn by Dave 27 chips gets you 48k ram,
OS in 8k Eprom, 2 serial ports, FDC that can handle 4 disks
(360/720 5.25 or 720k 3.5" and 8" is basicaly there). If you
recognize that the six 8Ksrams can be replaced with one 64k sram
you knock off 5 chips and the FDC portion is 10-11 chips alone
(basic 765 with ttl around it). If one could find a smc9229 FDI
or mod the circuit for 37C65 that chip count gets much smaller.
I happen to have some 64k srams and the majikal super rare
custom FDI so the chip count will be under 20. As small single
board systems go that is a very small chip count with out using
PALS/GALS.
I think a Floppy chip with a real built in data separator is the way to go.
Also a good dma is needed, as having the cpu do floppy I/O leaves
no margin for serial I/O.
The other thing is a NICE terminal to go with the system. I don't want
to boot
windows or dos to run a terminal. For development work a PC is a good idea
until you get a OS running. I have a used Altos IV here, from what the
keyboard
says but I don't know of how many years of life the terminal may have left.
Allison