david@ukma.uky.csnet (David Herron, NPR Lover) (09/30/86)
[All praise to the mighty line eater.... Please accept this sacr Hi y'all! I've just spent a few hours comparing the DUP-11 (Synch board for Unibus machines) and the DUV-11 (Synch board for Q-bus's) and I've got a few questions. What is going on is that we have this "old" 11/750 with a DUP-11 which we're using to connect us up to BITNET. We also have these 4 "new" uVaxII's and we're very very very very pleased with the performance on them. Eventually the service contract costs on the 750 will force us to replace it with something. But we need to remain attached to BITNET, meaning we either add a Synch port to one of the uVaxIIen or have the replacement machine posess a Unibus. (i.e. an 8xxx machine) (As an aside, is there a qualitative advantage to an 8xxx machine over a cluster of uVaxII's?) Now, with that as justification... The DUP and the DUV look very very similar. They have the same registers (though there are differences in the actual bits), and the same sort of philosophy (i.e. very basic synchronous interface). The important difference seems to be in details about transmitting a packet. In the DUP-11 there are some bits in the TXDBUF register that you set at special moments. For instance, for the first character of the packet you also set the TSOM bit, after the last character you set the TEOM bit, and there's a couple more similar bits. The DUV-11 has NONE of those bits. And, unfortunately, the manual I'm reading is a "later" sort of DEC manual so it doesn't go into enough detail for me to understand how it really works. (I have the 1980 Microcomputer Interfaces Handbook) 1) To send a packet out a DUV do you just light the SEND bit, wait for awhile while the DUV is idling synch characters out, then start shoving bytes into the TXDBUF register (waiting for TXDONE to light inbetween)? 2) The manual doesn't talk about doing lots of protocols like the DUP manual does. And it doesn't throw around buzz-words like SDLC or ADCCP either. Instead it says "internal synchronous", "external synchronous", and "isosynchronous". It also mentions the word "bisynchronous support" at the beginning. What does that mean? We're currently doing bisynch with ours to an IBM-308x. I suppose that "bisynch support" means we can continue doing that if we get this board, however "support" usually means you have to do something a little strange (i.e. it's not what it was specifically designed for, however we left this hook so you can still do it but you gotta bend over backwards a little bit). 3) The DUV suffers from the same problem as the DUP. That it is an INCREDIBLY DUMB board. Is there a newer board that we can (or should) get? (It'd be great if it were compatible with the DMF's synch port..) 4) Anybody have an idea when UREP V.3 will get out the door? :-) advTHANKSance -- David Herron, cbosgd!ukma!david, david@UKMA.BITNET, david@ms.uky.csnet (I'm also "postmaster" at all those addresses) (And "news" and "netnews" and "uucp" and ....)