[rescue] sun 3/60 update

[Phil Stracchino]

On 5/27/25 13:16, Romain Dolbeau via rescue wrote:
> Le mar. 27 mai 2025 à 05:35, Dan Moisa via rescue <rescue at sunhelp.org> a écrit :
> 
> I'd never realized that the "Sun-style" MMU on those machines was done
> in discrete logic and PALs... somehow from all the '030-era systems
> with gate-array custom chips, I expected to see that and wondered
> where you sourced them from... I understand now why they chose to do
> the sun3x for the '030 and use the built-in MMU - cheaper and smaller
> than having all of that on the board.


This is now making me think of a project I worked on around 1988 or 1989 
in association with NASA Dryden Flight Research Center.  We designed and 
built a modular embedded microcomputer running on INMOS Transputers 
(hardware parallel processing), all hand-wirewrapped prototypes, modules 
not much larger than a deck of cards, that stacked and fit inside a set 
of similarly stacked hermetically-sealed aluminum modules with liquid 
freon pumped through them for cooling.  We used high-density ZIP memory, 
built our own RAS/CAS refresh circuitry using quartz delay lines because 
nothing else on the market then was fast enough.  If memory serves, we 
could display somewhere on the order of 1280x960 graphics in 24-bit 
color, and could redraw the entire screen inside the flyback time of the 
CRT.

This ended up flying in the Hercules air-launched booster, in which the 
heatsink medium for the cooling was chicken fat inside the wing (chicken 
fat has a ridiculous specific heat capacity; Dryden bought the stuff in 
tank-car loads), as well as in, uh, other projects that I can't talk about.

It was a fun project to work on.


-- 
   Phil Stracchino
   Fenian House Publishing
   phils at caerllewys.net
   phil at co.ordinate.org
   Landline: +1.603.293.8485
   Mobile:   +1.603.998.6958