There's some information on tape widths and speeds at http://www.soundonsound.com/sos/jul04/articles/qa0704-3.htmGenerally, most domestic tape recorders used ¼" tapes, but there were different track formats. In the early days, there were two mono tracks, one in each direction, with the tape being flipped over when you reached the end, as with a cassette. I bought a Philips tape recorder in 1960 which had four mono tracks, which a switch to select which of the two tracks in the current direction you wanted. Later, when stereo came in, the left and right channels used separate tracks, so it was either 2-track single direction or 4-track like a stereo cassette.Speeds are measured in inches per second, generally 3¾ ips for domestic recorders, though the better ones could also record at 7½ ips. On some recorders, there was an option to record and play at 1⅞ ips for long recordings of speech where quality wasn't so important.
Richard Jennings ● 6277d