On 30th April I asked about how to determine and change the SCSI bus speed on
3000 series machines and their PMAZ{B,C} Turbochannel option cards.
I got just over a dozen replies. The situation seems to be as follows:
- On the early model 3000s (up to the model 500), the bus speed is fixed at 5
Mb/s, so there is nothing to change.
- On the model 600 and above, both buses can be set to 5 or 10 Mb/s. The
setting is determined by the console environment variables FAST_SCSI_A
(internal bus) and FAST_SCSI_B (external bus) which can be set OFF or ON.
- On the PMAZB option card, both buses are fixed at 5 Mb/s.
- On the PMAZC card, the buses can be set to 5 or 10 Mb/s. To display the
state you do
>>> t tc? cnfg
and you can set them with
>>> t tc? setid [s|f] [s|f]
where ? is the Turbochannel slot number.
The PMAZ cards are said to have a "write-protect" jumper for their on-board
EEPROM.
Nobody was able to give me a method of determining the current settings from
within a running system.
Many thanks to all who replied.
--
Martyn Johnson maj_at_cl.cam.ac.uk
University of Cambridge Computer Lab
Cambridge UK
Received on Thu May 15 1997 - 18:38:11 NZST