mike@lcra.uucp (Mike O'Donnell) (07/13/90)
Long ago and far away our MicroVAX II's outgrew their RD53 disk drives. As a result I have several laying around. However we have several Macintosh and PCs that could benefit from the larger drives. Is it possible to use these drives for PCs or Macs? Are there controllers available to support them? Any info will be greatly rewarded with massive appreciation. Thanks, Mike O'Donnell
chris@usc.edu (Christopher Ho) (07/17/90)
In article <10689@lcra.uucp>, mike@lcra.uucp (Mike O'Donnell) writes... >Long ago and far away our MicroVAX II's outgrew their RD53 disk >drives. Is it possible to use these drives for PCs or >Macs? Are there controllers available to support them? RD53s are Micropolis 1325s or 1335s which are standard ST506-interface hard disks (the difference between those two is in MTBF). These can be used directly on most PC controllers. For a Macintosh, you'd need an adapter board that tranlates from SCSI to ST506; Adaptec makes a couple boards with differing features. Chris
oys_carter@%odnvms@mps.ohio-state.edu (07/17/90)
In article <10689@lcra.uucp>, mike@lcra.uucp (Mike O'Donnell) writes: > Long ago and far away our MicroVAX II's outgrew their RD53 disk > drives. As a result I have several laying around. However we > have several Macintosh and PCs that could benefit from the > larger drives. Is it possible to use these drives for PCs or > Macs? Are there controllers available to support them? Any > info will be greatly rewarded with massive appreciation. > > Thanks, Mike O'Donnell I found myself in the same situation (with old RD53's that is). I'm preparing a paper for the Fall DECUS to discuss this issue (provided DECUS accepts my symposia proposal). I haven't completed my research yet but I'll tell you what I know so far. The RD53 is really a Micro1325 Disk Drive built by Micropolis. It has eight heads, 1024 cylinders and formats out to 67 MB (using an MFM controller). It uses the standard ST412/506 controller interface and as such will work with a PC controller. You will need a hard drive controller for your PC and a 20 pin and a 34 pin flat ribbon cable to make the connection between controller and drive. The electrical power connection is the same as on a standard IBM PC/XT power supply. While the drive is not intended for RLL encoding (so far as I can determine), I have been successfully running one in a PC for about six months using a RLL controller (Model ACB-2072 by Adaptec). To use it in a PC you will need to do a low level format of the drive. You can do that by going into DEBUG on the PC and typing the following: -G=C800:CCC <RET> Most controllers have a built in low level formatting program at that address. I've only run into one PC where the address is different (it was a NCR PC/XT clone). It will generally ask you a series of questions about how you want the drive formatted (ie., number of logical units, step pulse rate, number of heads, cylinders, offset encoding (for the defect table), etc.). After the low level formatting, you will need to do a DOS Partition and Format command (FDISK, and FORMAT). DOS 3.3 and below will only recognize a hard disk partition of 32 MB's or less and will only recognize two logical partitions per drive. If you use RLL encoding you will not utilize the entire drive unless you choose a to do the partitioning and formatting with a third party utility (ONTRACK Computer Systems, Inc. has one that I am testing but I don't have any results yet). I just used the Standard MS-DOS Vers 3.3 utilities with my PC. As a consequence I'm not utilizing some of the disk space. I finished my installation by running SpinRite II over the drive. It found that the PC had less than the optimal interleave factor and adjusted that for me. It also did a very worst case bit pattern over all the blocks on the disk and verified the formatting. On a PC/XT this was definitely an overnight task (about twelve hours). I would strongly recommend this software (or Norton's Disk Test might be OK too) before placing valuable data on the disk. Hope that this helps.