Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!mips!sjsca4!poffen From: poffen@sj.ate.slb.com (Russ Poffenberger) Newsgroups: comp.sys.ibm.pc.hardware Subject: Re: Mystery disk controller query Message-ID: <1990Aug23.161311.21567@sj.ate.slb.com> Date: 23 Aug 90 16:13:11 GMT References: <2969@aecom.yu.edu> Reply-To: poffen@sj.ate.slb.com (Russ Poffenberger) Distribution: usa Organization: Schlumberger Technologies, San Jose, CA. Lines: 40 In article <2969@aecom.yu.edu> werner@aecom.yu.edu (Craig Werner) writes: > > A friend with a noname clone and very very hardware manuals is >out of disk space, and we thought that the quickest, cheapest, and >easiest solution was to add a second ST-251-1 drive, boosting her from >40 to 80M. > Here's the problem. The drive controller manual is one that is >missing. I beleive that the controller is Western Digital. The large >writing says WA3-16. The largest chip on the controller, is a square >WD11C00C. > The controller has four jumper slots. J5 is a wide cable to the >floppies with two plugs, J4 is a wide cable to the hard with two plugs >(one free), J3 is a narrow cable to the hard drive with a single plug, >and J2 is free, but looks like it would take a cable the size of J3. > > What I'd like to know is what is the function of the cable at J3? >Why is it 1:1 unlike the wide cables at J5 and J4? What goes at J2? > >(Obviously the real question here is whether buying a bare drive is >sufficent or whether an extra cable needs to be ordered.) > > Sounds like you have a Western Digital WD1003. This is a 2:1 interleave controller that will support up to 2 floppies and 2 hard disks. The floppy cable (J5) supports two floppies directly with a little twist in the cable between the second and first drives. J4 is the command cable to the hard disks, again it daisy chains to two disks with a twist in the cable. Each of the small cables is for each of the hard drives. If you don't have a cable for the second drive, you need to get one. Russ Poffenberger DOMAIN: poffen@sj.ate.slb.com Schlumberger Technologies UUCP: {uunet,decwrl,amdahl}!sjsca4!poffen 1601 Technology Drive CIS: 72401,276 San Jose, Ca. 95110 (408)437-5254