brigman@stdc01.UUCP (James Brigman) (11/28/89)
Can you add a plain-jane serial-parallel PC-bus card to a DN3000 with a reasonable expectation of functionality? What kind of drivers would I need? Will the Context Corporation's Postscript Laser Print Server drive such a port? thanks for any and all info. James Brigman Star Technologies ...!uunet!rti!stdc01!brigman
lampi@pnet02.gryphon.com (Michael Lampi) (11/29/89)
The Apollo SPE (Serial Parallel Expansion) board was, originally, a bottom of
the line serial/parallel board to provide just such functionality. However, it
had insufficient buffering and/or intelligence so that the DN-xx00 would,
typically, spend most of its time servicing interrupts from the SPE when
simply printing a file.
The 'new' SPE has fairly deep FIFO buffers so as to reduce the number of
interrupts per character processed without loss of data on input.
Anyway, yes you can add such a board to a DN-3000. The driver would be pretty
simple, and you would have all the overhead problems that the Apollo SPE had.
One 'gotcha' is that you would probably have to write an extensible streams
type manager so that the Context printer server would know how to talk to your
board. Examples of such things are available with the Apollo Open Systems
Toolkit software package.
Michael Lampi MDL Corporation 213/782-7888 fax 213/782-7927
UUCP: {ames!elroy, <routing site>}!gryphon!pnet02!lampi
INET: lampi@pnet02.gryphon.com
"My opinions are that of my corporation!"jaeger@madnix.UUCP (Jay Jaeger) (11/30/89)
In article <580@stdc01.UUCP> brigman@stdc01.UUCP (James Brigman) writes: >Can you add a plain-jane serial-parallel PC-bus card to a DN3000 >with a reasonable expectation of functionality? What kind of >drivers would I need? Will the Context Corporation's Postscript >Laser Print Server drive such a port? We at WI DOT tried parallel ports, and /dev/pio seems to be being asked too much of - interrupt drive PC parallel ports don't seem to work very well. The Apollo SPE card comes with the appropriate drivers. If you want serial, your DN3000 has one built in (I think), and can be addressed as /dev/sio1 (or, if you buy special cable, 3 ports, adding /dev/sio2 and /dev/sio3). Hope this helped. (We GAVE UP on parallel ports...) Jay R. Jaeger State of WI, Department of Transportation madnix!jaeger (for now...)
krowitz%richter@UMIX.CC.UMICH.EDU (David Krowitz) (12/01/89)
To clear up a few things ... A IBM-PC/XT compatible parallel printer port is fairly easy to add to a DN3xxx/4xxx. The Apollo Serial/Parallel Expansion card (the SPE) has such a port built into it. If your print-server supports the SPE card, it will also work with the XT card -- they are hardware compatible. The driver software for the SPE may be another matter. You *definitely* don't want to drive the XT card (or the SPE) with interrupts turned on. Processing an interrupt for every single character sent will severely degraded the performance of the CPU. You want to use programmed I/O which (although it sits in a loop eating up CPU time waiting for the printer to accept the next character) will not degrade the performance of the other processes on the node. If I/O performance is a big issue, get the Ikon 10092 or 10097 parallel printer boards with DMA capability. The DN3000 only has a single serial port. The special cable adaptor which gives 3 serial ports works only on the DN3500, the DN4000, the DN4500, and the new DN2500. Adding extra serial lines via an add-in board is a pain. The software is much more complicated than for the parallel port. You'd be better off with one of the supported products from someone like Danford, Workstation Solutions, et-al. -- David Krowitz krowitz@richter.mit.edu (18.83.0.109) krowitz%richter.mit.edu@eddie.mit.edu krowitz%richter.mit.edu@mitvma.bitnet (in order of decreasing preference)
lampi@pnet02.gryphon.com (Michael Lampi) (12/02/89)
An alternative would be to purchase a serial-to-parallel converter (roughly
$80 to $120, depending on buffering and other options). Just plug it into a
standard serial port and direct the print server to that port.
Michael Lampi MDL Corporation 213/782-7888 fax 213/782-7927
UUCP: {ames!elroy, <routing site>}!gryphon!pnet02!lampi
INET: lampi@pnet02.gryphon.com
"My opinions are that of my corporation!"