Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pasteur!ucbvax!decwrl!purdue!i.cc.purdue.edu!j.cc.purdue.edu!pur-ee!frohne From: frohne@pur-ee.UUCP (Henry R Frohne) Newsgroups: comp.sys.amiga Subject: Re: Have you had a lot of bad floppies lately with your A500? The answer! Message-ID: <8090@pur-ee.UUCP> Date: 10 May 88 16:13:21 GMT References: <8805100305.AA09860@cory.Berkeley.EDU> Organization: Purdue University Engineering Computer Network Lines: 34 Summary: Home made drive details... In article <8805100305.AA09860@cory.Berkeley.EDU>, dillon@CORY.BERKELEY.EDU (Matt Dillon) writes: > : A500 with .5M extra memory (A501 look alike), one extra 3.5" > : floppy (not the A1010) which is an IBM floppy made to run on > : the Amiga using a couple of 74LS chips as has been discussed > : on the net, and a standard A500 power supply. > : > Sounds like either you forgot some bypass capacitors on the LS TTL > or you were overloading the poor A500 power supply with the combination > LS TTL and foreign disk. I have include bypass capacitors on all the 74LS chips (a 74LS38 and 74LS74) The floppy is a Toshiba FDD4206A0K. It may draw more current than the A1010. >Have you checked the amount of power the The voltage drop across the drive was a couple of tenths of a volt when in use on the 5 volt line and something similar on the 12 volt line. > floppy + support LS TTL is pulling? An IBM 150 watt power supply could > certainly (appear to) fix both problems. Where are you pulling the 5V for > the LS TTL from? I am taking the power from the DB-23 connector on the amiga. >How many chips and of what type are they? Are they *all* > LS? (Answered above.) By the way Matt, thanks for all the nice software you have shared with the Amiga community! Rob Frohne pur-ee!frohne