Service bureaus (Was: Tek 4051 firmware listing
chrise at pobox.com
Thu Dec 16 16:20:51 CST 2010
On Thursday (12/16/2010 at 08:28PM +0000), Tony Duell wrote:
> FWIW, I've just pulled a book off my bookshelf. 'Assembler Language
> Programmign, The IBM System/360 and 370', 2nd edition 1975.
> It says :
> 'Note that the letter O (Oh) is written as 0 to distinguish it clearly
> from the digit O (sero). We follow this convention in the description of
> any statement or card that is fed to the computer'
> So in that book (and presumably in other related manuals/documentation),
> the letter gets the slash.
And I have a model 33 teletype here, with some provenance claiming an
IBM lineage, that has a slashed-oh between the I and the P keys and an
unslashed-zero next to the 9 key.
Pressing the slashed-oh, sends 0x4F and pressing the unslashed-zero
sends 0x30... and conversely, it prints an unslashed-zero when 0x30 is
sent to it and it prints a slashed-oh when 0x4F is sent to it...
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