Pertec tape interface
From Computer History Wiki
The Pertec tape interface although never officially declared as such, was a de-facto industry standard for connecting tape drives from the 1960th onwards.
The serial Pertec interface consists of two 50-wire flat cables, with the majority of the pin-to-signal assignments being firmly defined. All odd-numbered pins are grounded, except for pins 1 and 3 on the second cable.
For technical details, see here.
Beginning in the 1980s, the Pertec tape interface was successively replaced by the universal SCSI interface, which is independent of the device type.
