WJM%UTRC@utrcgw.utc.COM (04/08/88)
With regard to the message saying jumper configuration for RD drives used in Microvaxes is not important, I would like to share this information: When used in a BA23 box, the drive # jumper (or switch, depending on the drive) must be set to DS#3 (Drive Select #3). When used in a BA123 box, jumpers on the M9058 'Disk Drive Cable Distribution Board' must be considered. The jumpers on this board determine which drive select signal will be used for selecting the drives. (Jumpers for each of the hard disk cables). The DS # on the RD drive must correspond to whatever numbering scheme is used on the M9058. The factory standard is to set all drives to DS#3, and have the M9058 set up to select drive #'s via which cable is used as long as the drive itself is set to DS#3. (This is why people have been able to do swapping between BA23's and BA123's without any trouble for the most part.) However, the M9058 also has jumpers to be set when an RX50 floppy unit is installed, and this can affect the RD #'s. The main reason for all this jumper business is when additional drives are installed outside of a BA box. Then an RQDXE expander board is used. This involves a jumper nightmare which you don't even want to think about unless you have to. Much of the above info is from the Microvax System Maint. Guide (which you get when you suscribe to the Microvax diagnostic service.) (Check pgs. 1-28, 4-73, 4-80-84)