sutter@osu-eddie.UUCP (08/04/85)
From: sutter (Bob Sutterfield)
Has anyone out there any experience with asynchronous DECnet (like on a
Rainbow or PC) over the Xyplex terminal service network?
--
Human: Bob Sutterfield
Facilities Management Division
The Ohio State University Instruction & Research Computer Center
Workplace: Ohio Cooperative Extension Service, Computer Management Group
OCES VAX System Manager/Programmer (VMS)
Mail: ...cbosgd!osu-eddie!sutter.UUCP
or: sutter@ohio-state.CSNET
MaBell: (614) 422 - 9034kvc@scgvaxd.UUCP (Kevin Carosso) (08/07/85)
In article <522@osu-eddie.UUCP> sutter@osu-eddie.UUCP writes: >From: sutter (Bob Sutterfield) > >Has anyone out there any experience with asynchronous DECnet (like on a >Rainbow or PC) over the Xyplex terminal service network? >-- One thing that may be a problem. If you want to run the async DECnet into a VMS system and if that VMS system has the Xyplex UNIBUS board you will have a problem. The way Xyplex handles terminals is that they have moved the entire terminal driver out of the system and onto their board. This is great if you want to reduce the amount of character processing the VAX has to do, but makes async DECnet impossible. You see, the VMS terminal driver is split into two parts. The class driver handles all the device independent stuff like line-editing, echo, all the wierd QIO modifers, etc... (about 95% of the terminal handling). The port driver is called by the class driver at the last instant to actually talk to the hardware in question. There is a port driver for the DZ-11, the DMF-32, etc... The way async DECnet works is that is has a special class driver that implements the DDCMP protocol. Therefore, async DECnet lines have the port driver corresponding to whatever hardware interface is in use, and a different class driver. Neat idea... Unfortunately, Xyplex chose to implement ALL terminal driver code in their board, so there is no way to get the DECnet class driver to handle one of their ports. I have talked to them about this (about 6 months ago) but at the time they showed no interest in fixing it... Indeed, it's not exactly clear how they could fix it, short of writing the equivalent of the DECnet driver into their board as they have the normal class driver... /Kevin Carosso {ihnp4 | allegra | seismo}!scgvaxd!engvax!kvc Hughes Aircraft Co. ps. If you are NOT using the Xyplex UNIBUS board, but just running lines from a cluster controller into a normal DZ or DMF, then the above does not apply. If your terminals are not TTcn: or TXcn: devices, but instead something like TP then you're out of luck.