Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!swrinde!zaphod.mps.ohio-state.edu!van-bc!mdivax1!brindle Newsgroups: comp.sys.mac.wanted Subject: Re: 400k Disk Drive Wanted Keywords: Disk Drive Message-ID: <1990Oct2.170049.3113@mdivax1.uucp> Date: 2 Oct 90 17:00:49 GMT References: <1990Sep27.170313.5329@athena.mit.edu> <57846@microsoft.UUCP> <15156@burdvax.PRC.Unisys.COM> Reply-To: mdivax1!fh06c!brindle (Jack Brindle) Distribution: usa Organization: Mobile Data International Lines: 25 Return-Path: Apparently-To: van-bc!rnews In article <15156@burdvax.PRC.Unisys.COM> dave@PRC.Unisys.COM (David Lee Matuszek) writes: > >Unless I am seriously mistaken, 800K floppy drives WILL NOT WORK with >the original 128K Mac. Don't waste your money! > >If I am wrong, well...I would love to know how to make an 800K drive >work on a 512K Mac. Flames welcome if they contain this very useful >information!!! Actually, 800K drives work quite well on 128K and 512K Macs. You simply need the HD20 startup file in your system folder. The HD20 file gives you support for the drive itself (both HD20 and 800K), as well as HFS support. It works better on a 512 than a 128 due to memory limitations. The bad news is you need to boot from the 400K drive in order to read in the HD20 file. Otherwise the Mac will try to access the drive as a 400K device. To put it another way, if you want to put an 800K drive in the internal slot, you really need to change out the ROMs. By the way, I use this configuration (internal 400K, external 800K) in several "servers" that provide specific functions. The servers consist of 512K digital boards with the drives and external power supply. They work quite well. I just wish the price of SCSI adapter boards would come down so I could scarf up several... - JackB.