scott@applix.UUCP (Scott Evernden) (11/25/88)
In article <6080009@hpcupt1.HP.COM> pdg@hpcupt1.HP.COM (Paul Gootherts) writes: >> $20 2 Cables (Some handiwork required) > >Please elaborate. I need to get/make a cable to go from the back of an >ST-225N (50 pin ribbon) to either a 50 pin SCSI connector or a 25 pin >MAC connector. > >What kind of cable do you run from your drive to your controller? If >you built it from scratch, how did you find out what the pin connections >are? Ok, the StarDrive is designed to make your A1000 look like a Macintosh to the disk (i.e., it supplies a DB25 connector). The ST277N disk has a 50 pin header. The challenge is to get a cable to go from the DB25 to the 50 pin header. Some people build a single cable which marries the 2. I think it's easier and cheaper to: 1) buy a standard-part Mac-style DB25 to Centronics SCSI cable 2) fabricate a ribbon cable to run from the Centronics connector to the 50 pin disk header. Apple actually charges about $50 (!) for the SCSI cable. Look around in Computer Shopper, and you can find one (18") for $10. The ribbon cable is the tricky part (not that bad)- You need to go to your handy electronics parts dealer and get: 1) a length (about 18") of 50 conductor ribbon cable 2) the 50 pin female IDC socket for the disk drive side. 3) the 50 contact female Centronic connector. Both of the connectors should be for ribbon cable use- that means that they can be "clamped" onto the length of 50 conductor ribbon cable. I scrounged for the ribbon cable; cost of the connectors was about $2 + $8. (You may have a little trouble locating part #3. I got mine at U-DO-IT electronics in Needham, MA) Study the pinouts below. The Centronics pin assignments are the same as the 50pin IDC's. So, you merely have to orient the 2 ribbon connectors properly, clamp each onto the cable with a Sears bench vise or such, and viola... Cable #2. Good Luck!! -scott DB25 - SCSI Pin Name ------------- 1 REQ 2 MSG 3 I/O 4 RST 5 ACK 6 BSY 7 GND 8 DB0 9 GND 10 DB3 11 DB5 12 DB6 13 DB7 14 GND 15 C/D 16 GND 17 ATN 18 GND 19 SEL 20 DBP 21 DB1 22 DB2 23 DB4 24 GND 25 N.C. 50 pin SCSI Header on Disk Pin Name Pin Name ----------------------------------- 1 GND 2 DB0 3 GND 4 DB1 5 GND 6 DB2 7 GND 8 DB3 9 GND 10 DB4 11 GND 12 DB5 13 GND 14 DB6 15 GND 16 DB7 17 GND 18 DBP 19 GND 20 GND 21 GND 22 GND 23 GND 24 GND 25 N.C. 26 N.C. 27 GND 28 GND 29 GND 30 GND 31 GND 32 ATN 33 GND 34 GND 35 GND 36 BSY 37 GND 38 ACK 39 GND 40 RST 41 GND 42 MSG 43 GND 44 SEL 45 GND 46 C/D 47 GND 48 REQ 49 GND 50 I/O Credit to Ed Gunther and Frank McConnell for portions of the above information.
mp1u+@andrew.cmu.edu (Michael Portuesi) (11/26/88)
scott@applix.UUCP (Scott Evernden) writes: > 1) buy a standard-part Mac-style DB25 to Centronics SCSI cable > 2) fabricate a ribbon cable to run from the Centronics > connector to the 50 pin disk header. > I have (1). Finding the parts for (2) are damn near impossible. Electronics distributors in Pittsburgh are lucky to know what a computer is, let alone carry parts for them. Radio Shack doesn't carry 50-pin anything. And my tour through Computer Shopper was none too helpful either. > I got > mine at U-DO-IT electronics in Needham, MA) What is their number, and do they ship Federal Express? I have had an idle hard disk sitting next to my Amiga for over a week now, and I'm getting pretty upset about the while affair. --M -- Michael Portuesi / Information Technology Center / Carnegie Mellon University INET: mp1u+@andrew.cmu.edu / BITNET: mp1u+%andrew.cmu.edu@cmccvb UUCP: ...harvard!andrew.cmu.edu!mp1u+ "my friends say she's a dumb blonde, but they don't know she dyes her hair"
scott@applix.UUCP (Scott Evernden) (11/27/88)
In article <MXXRCJy00VsfIdr1IX@andrew.cmu.edu> mp1u+@andrew.cmu.edu (Michael Portuesi) writes: >scott@applix.UUCP (Scott Evernden) writes: (in reference to Centronics and IDC connectors and ribbon cable for SCSI) >> I got >> mine at U-DO-IT electronics in Needham, MA) > >What is their number, and do they ship Federal Express? I'm sorry; here 'tis: YOU-DO-IT Electronics 40 Franklin St Needham, MA Phone 617-449-1005 I dunno if they do Federal Express, but I usually find myself waiting on some salesperson who's behind the counter on the phone taking orders - so I would suspect so... -scott