Subject: Re: Remote Backup Options (Was: Ripping and Storing CDs)
To: Steven M. Bellovin <>
From: David Laight <>
List: netbsd-users
Date: 05/28/2003 17:17:32
> The 9-track tapes of slightly later vintage were 
> 800 or 1600 bpi; in the mid-1970s, as I recall, those were succeeded by 
> 6250 bpi tapes.

Reminds me of some tapes we used for data interchange between a pdp11
and a Univac mainframe [1].  Occasionally they would be put into the wrong
drive on the mainframe and written with 6250 bpi 'phase encoded' data.
Our pdp11 would still read the 800bpi NRZ data....


[1] 6 bit characters in an EBCDIC like set and 36bit words written to
9 track (ie 8 data bit) tape.  Two 36bit words covered 9 'bytes' on tape.
Fortunately the characters were in the correct order on tape!

David Laight: