Marie, provided the correct answer, 1-7/8 in/s.
But, allow me to mention that some machines (including one or two amazing
Nakamichi machines) could run at 15/16 in/s.
Many of the Tascam (and similar) 4- and 8-track cassettes designed for home
music studios run at 3.75 in/s.
But the standard is 1-7/8 in/s.
Now, I need to know why you are asking--it sounds like the opening question of a
larger issue, like "can I transfer the cassette tape on a reel machine" or
something like that.
You can find the track configurations and lots of other (hopefully not useless
blather) at http://www.richardhess.com/tape/tips.htm
Richard L. Hess
Quoting Jonathan Wise <[log in to unmask]>:
> Dear ARSC folk,
> Can anyone tell me what the IPS is of a standard 90 minute audio-cassette?
> Jonathan Wise