Backups at 115,200 baud through DOS-73 board

[C M Votava]

Originally, Pete Fales tested this out, and told me about it, since then I
have verified it on my setup as well. The basic idea was to see if the
MS-DOS program "Brooklyn Bridge" would work between a DOS machine, and the
unix-pc's DOS-73 board. The answer is YES, it works fine!

For those of you that aren't familiar with "Brooklyn Bridge" (BB), it is
a program that will allows 2 PC's to share disk drives via the rs-232 ports
running at 115,200 baud. Here's a brief summary on how this is done. Connect
a null modem rs-232 cable to the serial ports of 2 seperate DOS machines,
and load the BB software on each of them. Choose which will be the slave,
and which will be the master. You run the "bridge" program on the slave,
and re-boot the master (making sure the config.sys file has the BB device
driver in it). When the master boots, the BB device driver will tack on
all of the available drives from the slave to the master. See the chart below
for an example:

		   Machines not running Brooklyn Bridge

	DOS machine 1				DOS machine 2
	A:	floppy				A:	floppy
	B:	floppy				B:	floppy
	C:	hard disk			C:	hard disk



	Master running Brooklyn Bridge

	(MASTER)
	DOS machine 1
	A:	floppy
	B:	floppy
	C:	hard disk
	D:	floppy drive A: of slave
	E:	floppy drive B: of slave
	F:	floppy drive C: of slave


So, from the master, you can copy files from c: to f: which will physically
transfer files from the master's hard disk to the slave's hard disk at
115,200 baud -- quite an acceptable speed.

Now, what does this have to do with the unixpc? Well, for those of you that
own 2 unix-pc's/DOS-73 combinations, or for those of you that have a 
unix-pc/DOS-73 and a regular DOS machine, you could use this to back up your
unix-pc's a lot easier than using the floppy. There is still a catch though,
the DOS-73 software will not recognize any file names not in the DOS format
(i.e. upper case with a 3 letter dot suffix) so what you have to do is to
create a cpio file under unix with a DOS-type file name, then go into DOS
and copy that file from one machine to the other.

Well, I know this all sounds like a real pain, but it's a good place to
start. Let's say that you're DOS machine has a 1.2MB floppy, or better
yet, a tape backup unit! It would be pretty nice to be able to use some
existing DOS resources to back up your unixpc! Eventually, I hope to have
a little program written to allow a unix task to send it's standard output
to the standard input of a DOS task. This way the unix command
"find / -print | cpio -oc | compress -c | dospipe" could be executed in
unix-land while the command "UNIXREAD E:\BAKFILE.CPO" command runs on
the DOS-73 board. This sequence would work very nicely to backup the unix
files to some remote DOS device. When/if I get the "dospipe" command and
"UNIXREAD" command written, I'll post it to the net (anyone want to help?).

In closing, I'd like to say that I'm fairly impressed with the DOS-73 board.
I've seen a large number of DOS programs run successfully on it, and am fairly
confident that ANY program that will run on a DOS compatible/with hercules
graphics should be able to run on this board. I've even been able to run very
ill-behaved programs like Microsoft Windows on it successfully -- there are
some glitches here and there (mostly in the unix side of the display software
I suspect) but those will be fixed soon. I am looking into replacing DOS 3.10
with DOS 3.2 as the O.S. to download to the board. There are also some people
looking into using the DOS-73 board as a co-processor to unix, running a custom
program instead of running DOS on it. A neat first step would be to write
a program that turns the board into another RS-232 I/O port so you could
run a getty on it. There are all sorts of "neat" things we could do with
this board and a little imagination!

If you are interested in any of this, or have any other ideas, please send
them to me -- let's see what we come up with!

-Craig Votava

[att!]looney!cmv