Siemens T100 Terminal with Paper Tape - Available

Paul Koning paulkoning at
Wed Dec 8 13:52:37 CST 2021

No, it's 5 bit tape.  2 data bits, transport sprocket holes, 3 data bits -- top to bottom on the reader (right side), left to right on the punch (left side).

DEC PDP-10 systems used six bit code internally but I don't remember those appearing on punched tape.  The punched tape machines I have seen with 6 channels are typesetting devices, from early tape operated Linotype machines (1940s vintage) to 1960s or 1970s era phototypesetters.  Those are upper/lower case.


> On Dec 8, 2021, at 2:23 PM, Mike Katz <bitwiz at> wrote:
> I thought I had recalled that Baudot was 5 bits but the paper tape is 6 bits across and I don't know of any 6 bit character codes except for DECs upper case only character set and even their paper tape had 8 bits so I guessed Baudot.
> On 12/8/2021 1:16 PM, Paul Koning wrote:
>> 5 bit; if it really were 6 bits it would typically be typesetting codes.
>> That's a relative of the machine used as console terminal on Dutch Electrologica X8 computers; I recognize the "Iron cross" symbol, the figures shift character on the D key.  But some of the other function codes have different labels so it isn't actually the same model.
>> The description I have says that the X8 console used CCITT-2, a.k.a., Baudot, code but with the bit order reversed.  And also that it used the all-zeroes code as a printable character rather than as non-printing fill.
>> 	paul

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