<OK, the MicroVAX has the main board which is mounted solder side up. It
<also has the extended memory card, a Network(?) card that connects via two
Yes the LANCE chip (NI) is on a smaller paddle board.
<40 conductor ribbon cables. What is missing is the large - almost main
<board size - board that is situated component side up beneath the main
<board, and connects to it via two 40 pin headers (that run parallel to
<the 50-pin and 60-pin connectors for tape SCSI and hard and floppy drives
<respectively) on the main board. Is that the Video Extension board?
Yes. Without it you have mono video or you can run using a serial terminal
via the printer port as console. The connector if pin 8 or 9 is grounded
tells it to use serial port instead of the video console. I've hard
jumpered mine so I can boot and run headless or use a more common cable
if I want a serial terminal on the system.
the 50 pin is the SCSI the 60 pins is HDC and floppy and the other larger
board is the video extension. Without the video board they are the same
beast.
<Does the position of the Berg jumper about two inches from the rear of the
<BNC connector affect the functioning of the storage devices?
No. The storage devices are always available if the system probe finds
them. It's possible to have a RX33 floppy(TEAC FD55GFV), MFM hard disk,
A second RD5X MFM and TAPE(TK50) via a SCSI bridge. NOTE: the scsi is
real SCSI hardware wise but the roms(and VMS drivers) do not implement
compatable SCSI protocal so the only standard device is the oddball TK50.
The SCSI oddity is from the mid 80s when SASI/SCSI was not a clear standard.
For hard disks RD54 is the most desireable but v5.x can be trimmed to
fit on a 71mb RD53 (DECwindows has to go,as I've got one here that way).
Terminal support is via the DB9 printer port. If you can find one there
is an adaptor P/N70-23766 that converts the video connector and the printer
connector to three RS423 MMJ serial ports.
I run all my VAXen to serial ports and a VT1200 DECterm, can't spare the
space for the usual VR260/290/320 or larger tubes. Since DECnet does
the equivelent telnet (and then some) one or two tubes are enough for
support and talk to all of them.
Hope this helps. I happen to have three of them, two running VMS and one
with Ultrix4.2 on it. To that two MicrovaxIIs, 3 MV3100/M10Es,
1 MV3100/M76 sharing the eithernet with two MS PCs and a Linux PC box.
Allison
Received on Wed May 19 1999 - 22:15:59 BST