PC coprocessor comments wanted

[Chris Rende]

References: <1991Jun3.155221.11868 at apollo.hp.com>

>From article <1991Jun3.155221.11868 at apollo.hp.com>, by bobp at gti.apollo.hp.com (Bob Plencner):
> 
>  I'm looking for facts/comments on the PC coprocessor 
> for the AT&T 7300 PC.
> 
>   Software -  What kind of software have you had
>               luck/no luck running on this board ?

DBase IV won't run due to lack of RAM. In general, you can forget anything that
needs more than 512k. :-(

>               Also, how is disk space allocated for the
>               coprocessor's "C:" drive ?

You pick how much disk space to allocate to the C: drive. Increments are in
1k bytes. Also, if you want a D: drive, you pick how much space it gets. You
can have as many drives as you want - kind of handy.

I have a minimal C: drive setup that contains DOS and the necessary basic
utilities need to run DOS-73. My C: takes up 2 Meg.

When I need to do something, I just create another virtual drive with enough
space to work in. Each user has a DOS-73 config file in their directory that
handles the mapping between the Unix pseudo hard drive files and the MSDOS
logical disks.

For example:

-rw-rw-rw-  1 root    root    2048000 May 26 22:46 dvd000   (Mapped to C:)
-rw-rw-rw-  1 root    root    3072000 Mar 24 21:57 dvd001   (Mapped to D:)
-rw-rw-rw-  1 root    root    2560000 May 26 22:46 dvd002   (Mapped to E:)

Additionally, one MSDOS disk can be mapped to the current Unix directory.
This gives an easy way to move files back and forth between Unix and MSDOS.

>   Graphics -  Does the board only run in text mode,
>               or can it use the 7300's bit-mapped
>               graphics ??

It has a text mode. It also emulates hercules graphics. However! only 80% or
90% of the graphics screen is visable at a given time, you have to press 3b1
function keys to view the hidden part of the graphics screen. Kind of a pain
but at least it's doable.

One important note about how the coprocessor works...
Whether the DOS side is in graphics mode or text mode the DOS system makes
changes to (what I'll call) video memory on the DOS coprocessor. The DOS73
driver constantly reads the DOS video memory and updates the 3b1 DOS73 window
to reflect the changes. This can produce strange effects for DOS programs
which update the screen rapidly or in real time. Flight simulator is one
example.

>      Mouse -  Can the mouse be used for DOS applications
>               that support the mouse ??

Yes.

> Installing -  Any difficulty installing the hardware
>               or software ??   Any revs to stay away
>               from ??

My 3b1 can with it all installed.

> Any other comments on the board ??

The MSDOS floppy drives A: and B: are translated to access the 3b1 floppy drive.
The MSDOS printer is redirected to the Unix print spooler.
You can leave an application running on the DOS-73 system even after
disconnecting from it. Great for intense chess games against the computer if
you leave your system on all the time.
One thing I miss is that there is no audio output for the DOS-73 system. :-(
You also cannot boot the DOS-73 card from floppy - only from a Unix psuedo
disk.

It's a nice product - I like it.

car.
-- 
Christopher A. Rende           Central Cartage (Nixdorf/Pyramid/SysVR2/BSD4.3)
uunet!edsews!rphroy!trux!car   Multics,DTSS,Unix,Shortwave,Scanners,UnixPC/3B1
car at trux.mi.org                Minix 1.2,PC/XT,Mac+,TRS-80 Model I,1802 ELF
trux!ramecs!car     "I don't ever remember forgetting anything." - Chris Rende