sizes (was Re: vacuum tube computer)

From: Eric Smith <eric_at_brouhaha.com>
Date: Mon Feb 1 14:41:04 1999

Chuck wrote:
> I remember the KL-10's at USC had 4 MWord memories that took up an entire
> rack. (4 Mword is about 16 mByte), so in 70's tech that my video card would
> be two racks, main memory would be 8 racks, ...

Sounds like USC was using the Ampex ARM-10 semiconductor memory box, the same
as Scott and I have on our KL10. DEC never offerred a single-box 4 MWord
solution; AFAIK they never offered any 4 MWord solution at all.

The ARM-10 uses 64K DRAMs, so it must contain about 2752 of them. Of course,
since the 64K DRAM wasn't introduced until 1981, it came about rather late
in the life of the KL10, which itself was introduced in 1975.

I have had in mind for some time to design a true "tube" CD Player. Not
the stupid "tube CD players" that are sold now, in which only the analog
output state is made with tubes, but one in which there are no ICs or
transistors. I think this could be packaged in two 19-inch racks (maybe
one if you can pack it really densely). I wonder how many audiophiles
would be willing to buy one at a price of $50K to $100K?

Although it would be nice to arrange to have no semiconductors in it at
all, realistically I think that semiconductor diodes will be necessary,
just as they were used in most tube-based computers. Otherwise you just
need too dang many tubes.

A little-known fact about the CD format is that it was specifically designed
(in the mid to late 1970s) so that a minimal player does not necessarily need
a microprocessor. A few early prototypes were developed that had no
microprocessor, but AFAIK all production CD players did in fact have one.

Eric
Received on Mon Feb 01 1999 - 14:41:04 GMT