klarich@a.cs.okstate.edu (Terry Klarich) (08/29/89)
I was wondering if the 1024 limit of cylinders allowed by MSDOS was hard coded? Or, is there anything I can do about it? I am using IBM dos 3.30; and my disk has 1224 cylinders. It gets the number of heads right. My drive is type 26. This has not been a problem before because I have Xenix on the last 700 cylinders or so. I would like to runthe utility "interleave Adjustment Utility" to improve my data transfer rate without removing all my data. I just got a new dtc rll 1:1 controller. Thanks
simcha@kurz-ai.UUCP (Simcha Lerner) (08/30/89)
In article <4905@okstate.UUCP> klarich@okstate.UUCP (Terry Klarich) writes: >I was wondering if the 1024 limit of cylinders allowed by MSDOS was hard >coded? DOS accesses the disk via IBMBIO.COM which hooks into the ROM BIOS. The IBM ROM BIOS only allots 10 bits to encode the cylinder number, therefor the 1024 limit. One way around it is to place a wedge between DOS and the BIOS (tricky since it is best done before dos becomes active) that logically remaps the disk to having more heads (or more sectors/track) and less cylinders. If you want more info on how to do this, contact at the e-mail address below (please don't use your respond key!) -- Simcha Lerner Kurzweil Applied Intelligence PLEASE NOTE ADDRESS: NO RETURN MAIL VIA bbn PLEASE UUCP address: kurz-ai!simcha@talcott.harvard.edu or: ...{uunet,rutgers,ames}!harvard!talcott!kurz-ai!simcha