[comp.sys.ibm.pc] Slave 286 cards??

jr@oglvee.UUCP (Jim Rosenberg) (07/23/88)

I know that there are some companies out there, such as Alloy, that make slave
286 cards that plug in a PC or AT bus.  Typically such cards are designed for
a "LAN-in-a-box" multiuser solution.  I'm curious to hear from anyone who may
have such a card whether any vendor is supplying decent enough documentation
of the card all the way down to "bare metal" that one could run DOS on the
slave card but a *different operating system* on the master.  Also, does anyone
sell a slave card with EGA on the slave?

Any help appreciated.
-- 
Jim Rosenberg                        pitt
Oglevee Computer Systems                 >--!amanue!oglvee!jr
151 Oglevee Lane                      cgh
Connellsville, PA 15425                                #include <disclaimer.h>

madd@bu-cs.BU.EDU (Jim Frost) (07/31/88)

In article <265@oglvee.UUCP> jr@oglvee.UUCP (Jim Rosenberg) writes:
|I know that there are some companies out there, such as Alloy, that make slave
|286 cards that plug in a PC or AT bus.  Typically such cards are designed for
|a "LAN-in-a-box" multiuser solution.  I'm curious to hear from anyone who may
|have such a card whether any vendor is supplying decent enough documentation
|of the card all the way down to "bare metal" that one could run DOS on the
|slave card but a *different operating system* on the master.  Also, does anyone
|sell a slave card with EGA on the slave?

I have used the Alloy system with v20 cards (not the new 286 cards).
They provide *very* little low-level information.  I believe that it
would not be difficult to tear apart their code to figure out how the
slaves communicate, but I don't have the time for that so I never did
it.  If you are looking to build your own software to use the
hardware, this system is probably not a good place to start (although
I didn't ask them if there was other documentation available).

On a high point, their MS-DOS operating system works very well for
most applications.  New enhancements in their terminal drivers have
made programs that do extensive video buffer writing operate
reasonably.  The documentation for the facilities they provide is
about as good as that given by the PC Dos Technical Reference.  There
were some errors in the version of the documentation that I have,
however, and their technical support has problems handling questions
that deal with their datagramming services.  In addition, I found that
some datagramming methods will crash their routines, although good
methods operate reasonably.  Some of the datagram interface routines
are poorly laid out and are impossible to use with high-level
languages without some machine language.  One such case is the
datagram interrupt service routine interface, which calls the
installed routine with a far call instead of an interrupt; compilers
that handle ISR's invariably return with IRET, not RETF.  It took
about 20 lines of assembler (most of it out of the Turbo Pascal 4.0
manual) to build my ISR.

If anyone would like information on the Alloy PC Slave system, I will
give honest, educated answers.  I have used and programmed the system
extensively for over three years; I can comment on any service except
their Novell emulation, which I have never used but which works fine
with several products that I have tried.

On a final note, the system I used was configured as follows:

	512k IBM AT (10 MHz clock added)
	EGA
	72 Mb hard disk (using Golden Bow's VFeature)
	8 1Mb Alloy PC Slave/16 cards (3 different revisions)

We use a variety of popular (and not so popular, eg DisplayWrite III)
packages as well as a lot of custom software.

jim frost
madd@bu-it.bu.edu