DELQA Switch Settings - test-drb@ccmp.vtda.org

23 Jan 1999

...
 It's looking like there is something with the way I
ran a SYSGEN a few
days ago.  It turns out that I can't even boot the SJ monitor, and the FB
monitor won't let me install the EQ driver.  However, the XM monitor
which I didn't even touch will let me install the EQX driver. 
I don't know the restrictions for EQ (under TSX, I suppose), but
having been the designer and implementer of the ethernet drivers
under RT-11, I can tell you that they won't run under SJ and FB.

By the time we started working on Ethernet, the target system for
most installations was XM.  When I started working on the design
for the ethernet drivers, there were several factors which guided
the decision to be XM-only:

	1) It was procedural to add and remove buffer descriptors
	   from the ring -- you had to ensure that the adapter
	   would not use one while the driver was working on it
	2) Receive buffers had to essentially always be available
	   or performance would have been abyssmal.
	3) There was a recommended minimum number of receive buffers, or
	   again, performance would suffer.
	4) Maximum sized receive buffers were required or we would
	   have had to support buffer chaining (which would have
	   added to the size and complexity of the driver code,
	   and as anyone familiar with RT knows, low memory is
	   at a premium -- and moving them to high memory was
	   not available under SB/FB)

So, since we had to have a minimum of 6 receive buffers, at the
maximum size (1600 bytes), that would have been just over 9kbytes,
and we haven't even added the space for the code.  This was
unacceptable for SB/FB.  It was decided that they would be supported
under XM only.

...
 I think my next step is to either redo the SYSGEN on
the SJ and FB
monitors, or to copy over the XM versions of the TCP/IP software.  I'll
probably copy over the XM versions first.  Unfortunatly we've got a
downtime at work tonite, so I've got to go into work in the next hour and
most likely won't be able to try this tonite :^( 
I don't think you have to do this... TSX doesn't use the exact same xx.SYS
drivers that SB/FB use, it uses rebuilt ones with a file type
of .TSX  So, as long as your TSX sysgen includes the driver, it
should be available...

And remember, TSX essentially takes over the machine, kicking the
former OS (RT-11 SJ) out of memory...

					Megan Gentry
					Former RT-11 Developer

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