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Path: utzoo!linus!genrad!decvax!yale-com!leichter
From: leichter@yale-com.UUCP
Newsgroups: net.misc
Subject: Re: Touch-Tone Pads (with "sidebar" about the Code-A-Phone 700)
Message-ID: <1695@yale-com.UUCP>
Date: Thu, 30-Jun-83 13:47:16 EDT
Article-I.D.: yale-com.1695
Posted: Thu Jun 30 13:47:16 1983
Date-Received: Thu, 30-Jun-83 23:37:38 EDT
Lines: 28

At least there really WAS a difference between the "minimum" and "maximum"
Code-A-Fones - even if it was artificially produced!  There is an interesting
story told about the CDC 6600 that used to be at NYU (I think it was retired
about a year ago.)  I am told this story is true, but perhaps not; maybe
someone at NYU will know and send corrections/details.

Anyway...NYU got a very early 6600 - serial number 3 or thereabouts.  Now,
there were two available memory options at the time:  The full 262K (60-bit
words0; or

\\\\\words); or the "half-size" 131K.  NYU decided that 131K would be fine,
thank you.  CDC kept trying to convince them that they really should get the
full memory; the extra cost wasn't that great, etc., etc.; but NYU was firm,
and the machine eventually arrived with 131K.

Sure enough, some hackers decided to see - probably after some program did
it by accident - what happened if you addressed the non-existent memory.
Oddly enough, writing to it caused no errors; reading back from it caused
no errors, and in fact gave you what you had written there; and writing to
the non-memory didn't seem to clobber any "real" memory locations either...
Apparently, CDC had never gotten around to trying to build a machine with
only 131K.  When they tried it, it didn't work.  So, since they had to get
NYU's machine out the door, they "removed" 131K in the documentation only!

							-- Jerry
					decvax!yale-comix!leichter leichter@yale

[If it's not true, it ought to be...]