15 May
2001
15 May
'01
4:05 p.m.
On Wed, 16 May 2001, Tony Duell wrote:
Are you planning to have some kind of automatic
high-speed seeking (I
assume so, since waiting 45 minutes (one side of a C90) to read a
block is rediculous). In which case you've not only got to modify your
transport to allow for electronic selection of a fast forward/rewind
mode that keeps the heads in contact with the tape, but also you've
got to have some kind of block marker (maybe just a gap in the data on
the tape) that can be detected when the tape is moving at high speed.
It's possible (and has been done many times), but it's not a trivial
problem.
You're assuming he won't do something clever such as add an electronic
counter so he can fast forward to just before the desired block?
In general the seeking speed is about 5 times the
normal play/record
speed on this sort of drive. That's still 9 minutes to seek from one
end of the tape to the other. This will get boring fast.
As I suggested, he can use the magnetic tape to wrap around some drum to
create a cool drum memory device :) There can even be multiple tracks,
with either one moveable head or multiple heads for faster access.
You do realise that any 8 bit micro will easily go
faster than an
audio-cassette based storage system.
I think the intent here is to create a more classic-type design rather
than a modernish design.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org