sizes (was Re: vacuum tube computer)

Chuck wrote: 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