so far off topic - capatob - saratov2 computer Russsian pdp8?

[ben]

On 1/7/2019 8:20 AM, allison via cctalk wrote:
snip...
> made though more likely 74F, AS, or LS variant and of course CMOS 74ACT
> (and cmos friends) as I just bought a bunch.  Dip is getting harder to
> get but
> the various SMT packages are easy.  Prices for 10 or more of a part are
> cheap to cheaper from primary suppliers.  The second tier suppliers are
> often several times that.

I got ebay... The bottom of the heap.

> I figure most of what I did back then is years before many here were born.
> 
> However I have enough NOS TTL 74LS, 74AS, 74F series to build several
> machines.

I have been playing around with a early 70's TTL computer design
and 74LS181's are too slow by 30 ns. Using a BLACK BOX model for core 
memory, I can get a 1.2us memory cycle using a 4.912 MHz raw clock
but I need a few 74Hxx's in there. Proms are 256x4 60 ns and 32x8 50 ns.

Do you have your 74Hxx spares? Eastern Europe still  has a few on ebay
with reasonable shipping for 100% American Russian parts.

> I'm still building, current project is a very compact Z80 CP/M system
> using CF
> for disk. Mine uses all Zilog CMOS for very low power.  Its a variant of
> the
> Grant Searle Z80 with memory management added to utilize all of the
> 124k ram and eeprom.  If you want go look there.

What do you use all that memory for?

> Allison
> 

The Chinese elves have been busy, My 5V 15 amp $20 power supply arrived
in the mail today. I have power to spare for my BUS and blinking lights.

Ben.