8 Dec
2021
8 Dec
'21
11:52 a.m.
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.
paul
On Dec 8, 2021, at 2:23 PM, Mike Katz <bitwiz at
12bitsbest.com> 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