14 Oct
2013
14 Oct
'13
3:46 p.m.
In the IEEE paper BOUKNIGHT et al: THE ILLIAC IV SYSTEM, April 1972
there is this paragraph:
BEGINQUOTE
1) Laser memory: The B6500 supervises a 10^12-bit write-once read-only
laser memory developed by the Precision Instrument Company. The beam
from an argon laser records binary data by burning
microscopic holes
in a thin film of metal coated on a strip of polyester sheet,
which is
carried by a rotating drum. Each data strip can store some 2.9 billion
bits. A "strip file" provides storage for 400 data strips containing
more than a trillion bits. The time to locate data stored on any one
of the 400 strips is 5 s. Within the same strip data can be located in
200 ms. The read and record rate is four million bits per second on
each of two channels. A projected use of this memory will allow the
user to "dump" large quantities of programs and data into this storage
medium for leisurely review at a later time; hard copy output can
optionally be made from files within the laser memory.
ENDQUOTE
The "10^12" is written as 10 superscript 12, I've shown it with caret
notation.
cheers,
nigel.
Unabashed Burroughs B5XXX/6XXX fan :-) with a wistful eye to the ILLIAC IV
>>> While reading the wikipedia article on the
ILLIAC IV there's a curious
>>> excerpt relating to the disk media:
>>>
>>> "They also provided a Burroughs B6500 mainframe to act as a front-end
>>> controller. Connected to the B6500 was a laser optical recording medium, a
>>> write-once system that stored up to 1 Tbit on a plastic disk covered with
>>> a thin metal film."