SINMICD@YaleVM.YCC.Yale.Edu (07/26/90)
This is a summary of responses to a question I posted in comp.sys.ibm.pc a few weeks ago in article <90191.000559SINMICD@Yalevm.ycc.yale.edu>. Since this is a more appropriate newsgroup for this discussion, I have moved it here. First, I would like to thank all who responded to my question concerning the use of more than one hard disk controller in the same machine. The responses I got were a mixed batch. Some said it wasn't possible, while others suggested I try formatting both drives to RLL and then using just the RLL controller. My problem is that the "other" drive is an original 10M Winchester drive from an AT, with older-type media that will probably not take RLL to well. Actually, I did try to put RLL on this drive, and it worked, but I still felt uneasy. Maybe those were the days when drives were shipped _without_ any defect list attached to them :-) I did get two responses that were helpful. It seems like it is indeed possible, but highly dependent on the brand of controller and the specific PC BIOS installed. Both my MFM and my RLL controllers have jumpers to set a secondary hard drive port address, but when I do this on either one it still doesn't work. It looks like my PC BIOS is not jumping to the secondary address like it should be. I still have a few more jumper combinations to try before I assume this is the cause. Here are the two responses I found most informative: davem@bitstream.com writes: >I use an RLL and an MFM drive (each formatted "properly") together on one >RLL controller in two machines that I have at home. I am using a WD RLL >controller in both cases. > >We have been able to get an MFM, RLL, and SCSI controller to all work >together in one machine at the office, each with one drive connected. We >set one of the MFM/RLL pair to the alternate address. The MFM/RLL were WD, >the SCSI was Future Domain. >> >On my 386, the bios does not support any RLL drive types. So I just >formatted the MFM drive as its normal drive type. I then used SpeedStor to >format and partition my RLL drive (really a Maxtor 1140 MFM 900 cyl x 17 >sec pushed to 1224 cyl x 26 sec). On my 286, I formatted the MFM with a >standard WD MFM controller, put in the RLL ctrl, added the 2nd drive, and >formatted it RLL and left the MFM alone. The 286 bios does support both >drives properly without using 3rd party drivers. > >I think it is up to the PC bios to jump to any additional bios addresses it >finds during startup. The ALR here at the office had no problem with both a >WD RLL and a Future Domain SCSI, with the SCSI set at the alternate >address. Ontrack sells a ROM with basically every drive type listed. I >bought one, and tried it in about five different PCs. Only one of them >would pass control to the ROM when booting (unfortunately not one of the >PCs I needed it to work in). I changed the bios in my 386 (one that did not >work) and the Ontrack ROM was invoked. blue@techunix.technion.ac.il writes: >Well, I have done so more then once. I have used diffrent combinations >of MFM and RLL controlers - and was able to boot and use the disk >without any problems. > From my experience, you have to be carful about the controlers >you use. Not all of the will enable you to run both. There is also the >question of who is first. Sometimes, switching the controlers will help. >I found out that the on-board BIOS has a lot to do with it - and of >courrse you have to put the two in diffrent address. > For example, I found out that an ST11M wont work as a first >controler when another OMTI 5527 (RLL) was installed. When I switched >them back, it worked. Thanks to all who responded, and feel free to send me more info, I still haven't had success yet. By the way, the controllers I'm trying to use are a Western Digital WD-1003 WA2 and an AMS RLL controller. My machine is a 386 with AMI BIOS. Mike Sintchak sintchak%hhvms8@venus.ycc.yale.edu