craig@nwnexus.WA.COM (Craig Suhadolnik) (12/30/90)
The solution to running a second RD54 in a MVII, concerning write protection etc, is to find the alternative style control panel to add to your BA23 box. These panels are included on some MVII BA23 boxes, and on some MicroPDP BA23 boxes. The panel has a second write protect switch for the second disk. The cabling is the same, and the panel is easy to install. I did this once when I configured a MVII in a BA23 without a TK50, the second RD54 resided in the TK50 bay. Send mail if you need help finding the panel! -- Craig Suhadolnik craig@nwnexus.wa.com 206/487-3616
terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr.) (12/30/90)
In article <451@nwnexus.WA.COM>, craig@nwnexus.WA.COM (Craig Suhadolnik) writes: > The solution to running a second RD54 in a MVII, concerning write > protection etc, is to find the alternative style control panel > to add to your BA23 box. These panels are included on some MVII BA23 > boxes, and on some MicroPDP BA23 boxes. The panel has a second write > protect switch for the second disk. The cabling is the same, and the > panel is easy to install. This is available from DECdirect +1-800-DIGITAL as part number BA23-UC. > I did this once when I configured a MVII in a BA23 without a TK50, > the second RD54 resided in the TK50 bay. Be very careful doing this. The BA23 power supply only delivers 7 amps of +12 (6 if it's an older model). Two full-height disk drives in a BA23 _will_ exceed the capability of the power supply. I've found that either running an external power supply cable for the second drive, or extending the second drive's data cables out to an ex- ternal box, works just fine. Of course, to have a "supported" configur- ation with two full-height drives, DEC wants you to have an RQDXE exten- der card and a RD5x-DA external mounting box. However, as we're a self- maintenance shop, support issues are of little concern to us. Lastly, even with just a single full-height drive, you may have a prob- lem, since there was an FCO to the BA23 (and BA123) wiring harnesses. The older ones tended to burn up and cause very nasty failures. The correct harness has white connectors and individual wires. If your harness has yellow connectors, or the cable is webbed ribbon style, contact your Field Service provider to get the FCO installed. Terry Kennedy Operations Manager, Academic Computing terry@spcvxa.bitnet St. Peter's College, US terry@spcvxa.spc.edu (201) 915-9381
don@zl2tnm.gp.co.nz (Don Stokes) (12/31/90)
terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr.) writes: > I've found that either running an external power supply cable for the > second drive, or extending the second drive's data cables out to an ex- > ternal box, works just fine. Of course, to have a "supported" configur- > ation with two full-height drives, DEC wants you to have an RQDXE exten- > der card and a RD5x-DA external mounting box. However, as we're a self- > maintenance shop, support issues are of little concern to us. One of our local field servoids described to me a configuation involving a BA23 (don't remember offhand if it was a pdp11 or MicroVAX II) with a TK50, two full-height drives and RX50s, the TK50 and second hard disk living in a cannibilised Rainbow chassis. I think FS were actually supporting this too (mind you, our Field Service crowd will support anything if pay them enough) > Lastly, even with just a single full-height drive, you may have a prob- > lem, since there was an FCO to the BA23 (and BA123) wiring harnesses. The > older ones tended to burn up and cause very nasty failures. The correct > harness has white connectors and individual wires. If your harness has > yellow connectors, or the cable is webbed ribbon style, contact your Field > Service provider to get the FCO installed. Free too, at least mine was (I installed it myself, mind). Don Stokes, ZL2TNM / / don@zl2tnm.gp.co.nz (home) Systems Programmer /GP/ GP PRINT LIMITED Wellington, don@gp.co.nz (work) __________________/ / ---------------- New_Zealand__________________________