21 Oct
1999
21 Oct
'99
2:52 a.m.
IIRC, the 8080 was about 4000 MOSFET transistors. If
you implemented it
with individual FETs, and packed it densely, I think you could fit it in
a 10.5" high rack space easily, and a 5.25" high rack space with difficulty.
Of course, you'll need plenty of forced air cooling. From a serviceability
point of view, building it less densely is clearly better.
True.
If you implemented it with bipolar transistors
configured as saturating
logic, it would require perhaps twice as many transistors and a lot more
resistors for TTL logic, or 50% more transistors, a lot of diodes, and a
lot of resistors for DTL logic.
Also true. A lot of the power estimates have been based on the assumption that
we have bipolar transistors. What about discrete mosfets? We could do NMOS or
even CMOS designs directly that way...
I liked Hans's suggestion (which I have now deleted, alas) of a museum exhibit
with three identical computers, but with processor as single chip, board of
gates, and rack of trannies for comparison. It does provide a service that you
couldn't get another way...
... or could you? Didn't PDP8 come in all three versions?
I've often wondered if you could build a transistorised computer without pcbs at
all. You know, trannies on tag board, little plugs bolted onto the ends (or on
flying leads) and so on... I was assuming ECL for two reasons - if you use
early transistors (Ge), ECL would probably be the only way to go at all fast;
and ECL gives the advantage of easy differential line drivers and receivers for
long interconnects.
Philip.
This E-mail message is private and confidential and should only be read
by those to whom it is addressed.
If you are not the intended recipient, you are hereby notified that any
dissemination, distribution, copying, reproduction, modification or
publication of this communication is strictly prohibited. Please delete
the message from your computer and destroy any copies.
This message is not intended to be relied upon by any person without
subsequent written confirmation of its contents. This company therefore
disclaims all responsibility and accepts no liability of any kind which
may arise from any person acting, or refraining from acting, upon the
contents of the message without having had subsequent written
confirmation.
If you have received this communication in error, or if any problems
occur in transmission please notify us immediately by telephone on
+44 (0)2476 425474