ac999321@umbc5.umbc.edu (ac999321) (05/26/91)
Hello,
About a week or so ago, there was a thread about using a
floppy tapedrive with a 3b1 and it was mentioned that hardware
mods for a second floppy drive would be necessary in order to do
this. Wouldn't it be just as feasible to either:
a. Disconnect the present floppy drive and hook up a tape drive
in its place; seems that this solution would be about the
simplest way to go for regular backups. In the event of a
hard-disc failure, the floppy drive could be reconnected for
the reinstallation of the foundation set, etc. and then the
tape drive could be reconnected for the restoration of
everything else and for future backups.
or.....
b. Similar to 'a' above, only instead of having to physically
connect and disconnect the floppy and tape drive, build some
sort of bouncless switching circuit to switch between the
tape and floppy and install a switch somewhere on the cabinet
so that the change would only require the 'flip of a switch'.
Has anyone tried doing either of the above?
--
**********************************************************************
Robert D. Davis #
rdavis@jhunix.hcf.jhu.edu # _REAL_ Education = The Benny Hill Show
+1-301-744-7964 (home) #dnichols@ceilidh.beartrack.com (DoN Nichols) (05/27/91)
In article <1991May26.061914.9033@umbc3.umbc.edu> ac999321@umbc5.umbc.edu (ac999321) writes: > > >Hello, > About a week or so ago, there was a thread about using a >floppy tapedrive with a 3b1 and it was mentioned that hardware >mods for a second floppy drive would be necessary in order to do >this. Wouldn't it be just as feasible to either: > > a. Disconnect the present floppy drive and hook up a tape drive [ ... ] > b. Similar to 'a' above, only instead of having to physically [ ... ] I don't know about other floppy tape drives, but the one used in the unix-pc uses the side-select line, and the drive-select lines to position the head over the track of interest at the given instant. These lines aren't even connected to driver chips in the 3b1, except for the lowest drive-select line and the side-select, which are used in the control of ONE floppy disk drive. The floppy-tape drive is controlled by a floppy-disk controler CHIP, with lots of strange logic around it to generate the combination of signals required by the drive. It, of course, needs a special loadable device driver, while the floppy-disk controller chip is under the control of a driver COMPILED INTO THE KERNEL, making it difficult to disable, so it doesn't fight your own loadable driver for control of the chip. I think that any attempts to use the floppy-disk controller built into the machine for controllng a floppy tape drive are just asking for trouble, unless other floppy-tape drive interfaces are less likely to cause problems when asked to share space with a floppy-disk drive. (Something which simply used the step-in and step-out lines to select track number, if made, would be easier to interface, but it still would need to convince the kernel to stop playing with the controller chip.) Good Luck DoN. -- Donald Nichols (DoN.) | Voice (Days): (703) 664-1585 D&D Data | Voice (Eves): (703) 938-4564 Disclaimer: from here - None | Email: <dnichols@ceilidh.beartrack.com> --- Black Holes are where God is dividing by zero ---