25 Jan
2012
25 Jan
'12
7:53 p.m.
On 2012 Jan 24, at 12:20 PM, Mike Loewen wrote:
On Tue, 24 Jan 2012, Andy Holt wrote:
Whirlwind never used Williams-tube storage, at least as I understand
the definitions. I don't believe it is even historically accurate to
say ".. Whirlwind used a modified form of the Williams tube".
Williams-tubes memory (or the preferred "Williams-Kilburn-tubes") and
the first memory system of Whirlwind were both electrostatic CRT-
based storage. The design approach of the Williams-Kilburn-tube-
memory was intended to enable the use of standard or off-the-shelf
CRTs, while the Whirlwind design used specialised holding-beam CRTs.
Causal influences are another matter. The CHM website suggests the
influence was the other way (MIT->Manchester). My understanding was
that they were simply separate developments of a common concept.
--
For reasons explained in a following message, I wouldn't trust that
"history-computer.com" site for much of anything.
Further web searches lead me to the IBM 706 which
was the main
memory of the
IBM 701 system. The object looks like one of the 18 units that
together
provided 2K 36 bit words of storage (and thus provides 4K bits,
not bytes,
of memory). (and, yes, these are 3" diameter at the face plate)
An early version of the Whirlwind computer also used Williams
Tubas:
"Initially Whirlwind used a modified form of the Williams tube. An
additional flood gun maintained the pattern of dots while a writing
gun was used to alter the pattern. Thirty two such tubes were
needed to provide the 4KBytes of storage that the Whirlwind needed.
Given a tube life of one month and cost $1000 the running cost of
the machine was very high, $1 per bit per month."