afc@shibaya.lonestar.org (Augustine Cano) (10/23/90)
When I took apart my 3b1, I noticed that in the metal sheet under the left
fan, covered by solid plastic when the machine is closed, is a cutout that
I gess was put there in anticipation of some future expansion (P6 with its
external disk?)
Could someone knowledgeable in the details of connectors and/or (newer?)
Unix PCs tell me what connector was destined to go into that cutout?
I'd really like to have a clean connection to the outside once I install
John's HD2 board. Any counter-indications to have the external HDs
plugged in into a suitable connector? Which connector would do?
(hopefully it would fit into that cutout.) I'd be all for developing
a net-wide standard pinout for such a connector that would allow access
to all the hardware capabilities of John's board (1 external floppy and
up to 4 HDs once the gd driver is suitably modified.)
The physical location and environment of my 3b1 does not allow locating
the external box for the drives within 1 or 2 feet of the machine. I
could put the external drives (floppy and HD) in a rack-mounted box with
PS that would require a 5' cable. I was thinking of those braided ribbon
cables used for connecting microcontroller software development boxes to
PCs, which in many cases are much longer than that. Obviously those
cables are desiged for low cross-talk and thus should be suitable for
connecting the disks through that length of cable. Does anybody think
otherwise?
How is everybody else thinking of the external aspects of the HD2 upgrade?
I have recently read in a local group that the cheap alternative (putting
the external disk(s) in an AT box with an AT power supply) might not work
very well. The person who tried this approach said that cooling was poor
and the PS was not loaded enough to work properly with one drive.
Comments, anyone?
--
Augustine Cano INTERNET: afc@shibaya.lonestar.org
UUCP: ...!{ernest,tsci,egsner}!shibaya!afcdave@dms3b1.uucp (Dave Hanna) (10/24/90)
In article <1990Oct22.233531.9378@shibaya.lonestar.org> afc@shibaya.lonestar.org (Augustine Cano) writes: > >I'd really like to have a clean connection to the outside once I install >John's HD2 board. Any counter-indications to have the external HDs >plugged in into a suitable connector? Which connector would do? >(hopefully it would fit into that cutout.) I'd be all for developing >a net-wide standard pinout for such a connector that would allow access >to all the hardware capabilities of John's board (1 external floppy and >up to 4 HDs once the gd driver is suitably modified.) One difficulty with that is that ST506/412 type drives require one daisy-chain control cable that runs to all the drives, a la floppies, but they also require a radial data cable that runs one to each drive. That means you'd either need a lot of pins, or, four 4 drives, 5 cables. >How is everybody else thinking of the external aspects of the HD2 upgrade? >I have recently read in a local group that the cheap alternative (putting >the external disk(s) in an AT box with an AT power supply) might not work >very well. The person who tried this approach said that cooling was poor >and the PS was not loaded enough to work properly with one drive. I'm not sure about the cooling, but I was planning to use one, perhaps with a smaller supply (e.g., the XT-type supplies are rated at about 135 watts, if I remember right, instead of the AT-type rated at 200 or more), and pull the drive out of the 3b1. With them both mounted there, that ought to be enough load on the supply. > >Comments, anyone? > >-- >Augustine Cano INTERNET: afc@shibaya.lonestar.org -- Dave Hanna, Infotouch Systems, Inc. | "Do or do not -- There is no try" P.O. Box 584, Bedford, TX 76095 | - Yoda (214) 358-4534 (817) 540-1524 | UUCP: ...!letni!dms3b1!dave |
njc@rick.att.com (Neil Cherry) (10/26/90)
>How is everybody else thinking of the external aspects of the HD2 upgrade? >I have recently read in a local group that the cheap alternative (putting >the external disk(s) in an AT box with an AT power supply) might not work >very well. The person who tried this approach said that cooling was poor >and the PS was not loaded enough to work properly with one drive. I'm going to put the whole thing into a PC/XT case. What I need to know if the 2nd drive board is still available and is it the one that allows me to use up to 4 drives. Also how do I get either version and cost. Not too much to ask. NJC