The document refers to 8 bit (7+P+F) and 7 bit (6+P+F) using the same width, 25.4mm, for ECMA-10.
>From the docs that have been linked, whirlwind tape was 7 bit, but not EIA-RS-227 or ECMA-10 compliant, but easily re-created by trimming a data bits width from normal 8 level tape. (LSB should be trimmed, not MSB, I think) I have a teletype BRPE which supported a 7 level tape format, but I do not know if it was ECMA-10 or whirlwind style, but it may be buried in the docs available online. -Eric On Fri, Mar 26, 2021, 8:10 PM Ron Pool via cctalk <cctalk@classiccmp.org> wrote: > On 3/26/21, 8:41 PM, "cctalk on behalf of Paul Koning via cctalk" < > cctalk-boun...@classiccmp.org on behalf of cctalk@classiccmp.org> wrote: > > I can't find right now the drawings that show all the 5..8 channel tape > layouts and dimensions, but I did see a > > number of references that speak of 7/8th inch tape for 7 channel > layout. (Also 11/16 for the 5-channel case) > > ECMA-10 defines some of the common punched tape layouts and includes > dimensions and other requirements. > I'm not sure if this is the document that Paul is referring to. > > https://www.polyomino.org.uk/computer/ECMA-10/ > > > >