8 Mar
2025
8 Mar
'25
3:41 a.m.
On 2025-03-07 1:36 p.m., Holm Tiffe via cctalk wrote:
Hi all,
I'm dreaming to build sometimes my own Bit Slice CPU (when I have spare time)
and I have collected several IC's in the last years for this purpose.
Today a small antistatic bag with 4x IDT49C402BG84 and two IDT 49C410J
fell in my hands while I was sorting some stuff.
You really want N3002N 2 bit, bit slices, 9 for 18 BITS, 10 for 20 BITS.
I know what they are and what they could do, they are
able to help me
to build a Bit Slice CPU w/o very large PCB's connecting hordes of 2901 etc.
Besides of that they are CMOS and should draw much less power.
But I have a problem with the 49C402: All datasheets that I could find
until now, don't have the pinput auf that nice PGA84 package, there are
DIP68, LCC/PLCC68 G68 or PG68 and QE68 "Cerquad" pinouts listet in every
datasheet, but I have 4 chips in a PGA84 housing...
if you must go to the dark side, 16 or 32 bit design pick up
a 16 bit alu in a PLCC 68 package. I have been doing a lot
of work with CPLD's ATF1508 and (the chips are easy to program)
are easy remove/insert into the sockets.
https://store.rosco-m68k.com/products/little-atf-programmer
I had some 16 bit slices, but had problems with the 64 pin dip
package for a 20 bit cpu. I later tried a regular 2901's.
I also needed to use 22v10's all over the place.
The biggest problem was design had bus timing issues,
it worked for few minutes and then quit.
This ebay page has pictures:
https://www.ebay.com/p/10020043211
I don't have anything todo with the seller.
Poland seems to have alot of odd stuff on ebay
like N3002's. Hint, Hint :)
While waiting for data, now is good time to think about software.
Ben.
Kind Regards,
Holm
PS.
I have older pcbs mostly working, of a 18 bit cpu ready to go to a good
home.
PPS. Still writing software, so the hardware is not ready to ship. You
do want a working bootstrap program!