What are the good and bad points of the QIC-11 and QIC-24 tape formats?

We have a Sun which supports both formats and I would like to know if one

of these formats is better in some sense.

I would also like to know how to calculate dump(8) tape length for a say

9 track cartidge tape. I do not have the source for Sun dump but I suspect

that dump regards all tapes as 8 track (8 data plus parity). My guess is also

that 9 track cartridge tape is used by writing 8 data bits and 1 parity bit.

Is this the case?

The formula I am using right now for calculating tape size is as follows:

I use the tape size written on the cassette with no safety margin!

density = 10000 (thats ten thousand)

size = 450 feet

My guess is that one of the following formulas is correct:

(tape size)*((9 tracks)/(8 tracks))*(safety factor)

(tape size)*(safety factor)

where (safety factor) is something like 0.9 or 0.94 (depending on who

you talk to).

--

Johan Widen

SICS, PO Box 1263, S-163 13 SPANGA, SWEDEN

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