Path: utzoo!attcan!uunet!snorkelwacker!ira.uka.de!ifistg!ifi!boegehol From: boegehol@informatik.uni-stuttgart.de (JN.V9obQ) Newsgroups: comp.sys.ibm.ps2.hardware Subject: Re: Adding An Extra HD To A Model 80-115... Message-ID: Date: 20 Jul 90 15:06:35 GMT References: <82186@tut.cis.ohio-state.edu> Sender: news@ifistg.uucp Organization: IfI, Univ. Stuttgart, W Germany Lines: 41 In-reply-to: mowgli@bat.cis.ohio-state.edu's message of 17 Jul 90 06:24:46 GMT In article <82186@tut.cis.ohio-state.edu> mowgli@bat.cis.ohio-state.edu (Mowgli Assor) writes: | We're considering adding a 330 or 660 Megabyte hard drive to our IBM PS/2 | Model 80-115. It's got an ESDI drive right now, & it appears the controller | will handle 2 drives. But, I'm not sure. Has anyone added a second hard | drive to their machine? If so, please let me know what you added & how it | went. Can I just buy any old ESDI drive & plug & go? Half a year ago, I added a NEC (oops, forgot the number) ESDI hard disk (147MB formatted) to my PS/2 Model 60-071. It was not quite as easy as plug & go. The problem was the low level formatting of the hard disk. The IBM ESDI Controller expects a "Primary Defect Map" on the second last cylinder of the hard disk. This is of course supplied with all IBM Disks, but not with my brand new NEC disk. The trick is to coerce the controller to ignore the primary defect map and just go ahead and format the disk. The Controller command for formatting has a special bit for that purpose, and I patched the program LLFORMAT.COM on the reference diskette accordingly. I was then able to format the disk with no problem, and I'm now using it with DOS and OS/2 without any special drivers or patches. I think the same procedure should also work for the Model 80 and also for other brands of ESDI hard disks. One problem might be the data transmission speed of the hard disk: The IBM controller is capable of handling up to 10 MBit/s. While experimenting with my NEC harddisk I borrowed a 330MB Disk from my friend's COMPAQ. That disk operates at 15 MBit/s and did not work with my PS/2. I have also heard of commercial software being available to format non-IBM hard disks, but I don't remember the name now. Furthermore, there are ESDI hard disks offered specifically for PS/2 machines. Those should work too, of course. When you actually need the patch for LLFORMAT.COM, please ask again since I don't have it handy right now. Hope that helps Harald Boegeholz