[net.wanted] 4.2 BSD Driver For DUP11 Board

cwh@riccb.UUCP (Carl Hopkinson ) (08/05/85)

	The Subject line pretty much says it.  We need a driver
	to talk to a Wang. Source code preferred.  We have
	a System V source license if this is a consideration.
	Let's talk.

	-Carl Hopkinson (312)-960-8240

jbn@wdl1.UUCP (08/23/85)

     Don't expect too much.  The DUP11 is a synchronous variant on the DL11;
it has one (1) byte buffering on both input and output, and thus must be
serviced every millisecond without fail at 9600 baud.  Not only is it a 
machine hog, there are interrupt lockouts longer than 1ms in 4.xBSD.  
     Some years ago I wrote a driver for this turkey for 4.1BSD for use with 
UNET.  It lost bytes above 600 baud, due to long interrupt lockouts in UNET and 
other parts of the system.  Interestingly, VMS drives DUP11 devices just fine,
but VMS has a less interrupt-lockout oriented internal architecture than Unix.
     You could drive it via a KMC, I suppose...

					John Nagle