🚀 go-pugleaf

In article <1993Jan11.160754.1011@dragon.com>, cts@dragon.com writes:
> I have various MicroVAX II systems with Telebit worldblazers attached.
> Currently, these are using DHV11 interfaces, which top out at 19.2 kb.
> It appears this is the bottleneck;  what options exist for getting faster
> speeds on an MVII, if any?
> 
> The top speed of the DHV/DHQ/DZQ appears to be 19.2;  the only board
> that's 38.4 capable for the Qbus is the CXY08, and it looks like this
> board isn't supported on the MVII.
> 
> Any suggestions?  I've considered getting a DLV11-J, and adapting the
> driver from the decus tape;  however, I'd rather have a DMA capable
> device....
> 
>   Charles Smith
>   cts@dragon.com
> 
-- 
Charles,
 
As far as the DLV-11J, you will not have much luck. The DLV-11J 
is, for all intents, unbuffered (it only buffers two characters 
if I remember correctly) additionally, you will get an interrupt 
for every character. This will have a hard time at 9.6-19.2 kb, 
much less at higher speeds.
 
I hope that the above is useful. If I have been unclear, please 
feel free to contact me via email or phone.
 
- Bob
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In article <1993Jan11.160754.1011@dragon.com>, cts@dragon.com writes:
> I have various MicroVAX II systems with Telebit worldblazers attached.
> Currently, these are using DHV11 interfaces, which top out at 19.2 kb.
> It appears this is the bottleneck;  what options exist for getting faster
> speeds on an MVII, if any?

  One of my UUCP leaf sites has an MVII with a DHV11. That system is pretty
busy, yet they average 1350+ CPS using DECUS UUCP.

> The top speed of the DHV/DHQ/DZQ appears to be 19.2;  the only board
> that's 38.4 capable for the Qbus is the CXY08, and it looks like this
> board isn't supported on the MVII.

  The CXY08 is an S-box version of the DHQ11. Functionality should be iden-
tical.

> Any suggestions?  I've considered getting a DLV11-J, and adapting the
> driver from the decus tape;  however, I'd rather have a DMA capable
> device....

  Bleh! DL11's have no silos and are interrupt-per-character. If you're going
to go through the trouble of doing a driver, either get a KXT11/KXJ11 and do
it on a coprocessor or buy a complete kit from Simpact. If you want a more
"stock" solution, get an Ethernet board (if you don't already have one) and a
DECserver 700.

	Terry Kennedy		Operations Manager, Academic Computing
	terry@spcvxa.bitnet	St. Peter's College, Jersey City, NJ USA
	terry@spcvxa.spc.edu	+1 201 915 9381

In article <1993Jan11.160754.1011@dragon.com> cts@dragon.com writes:
>I have various MicroVAX II systems with Telebit worldblazers attached.
>Currently, these are using DHV11 interfaces, which top out at 19.2 kb.
>It appears this is the bottleneck;  what options exist for getting faster
>speeds on an MVII, if any?

We have used a 3rd party product from Dilog (model CQ-1620) on our
MVIIs and were quite satisfied with them.  They emulate a DHV11 quite
faithfully (including the fact that they recognize only one level of
interrupts, just as the DHV11 does :-( ).  In VMS 4.7 DEC did not
allow you to enter a speed greater than 19200, so Dilog used an
improbable speed=(4800,134) as the sign that you really wanted
a speed of 38400.  There were other 3rd party products available when
we were shopping and we looked at one other vendor, but their product
did not perform correctly in our system.

-- 

Jeff Watts
jeff@tamri.com