Path: utzoo!utgpu!water!watmath!clyde!att!ihnp4!cbmvax!grr
From: grr@cbmvax.UUCP (George Robbins)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Amiga 500 external floppy disk failure
Message-ID: <4489@cbmvax.UUCP>
Date: 15 Aug 88 02:32:34 GMT
References: <238@nlgvax.UUCP>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Organization: Commodore Technology, West Chester, PA
Lines: 24

In article <238@nlgvax.UUCP> hans@nlgvax.UUCP (Hans Zuidam) writes:
> From: Andrew Dickman (Philips Telecommunications and Data Systems)
> Subject: Amiga 500 external floppy disk failure
> 
> We have an Amiga 500 which (after booting) thinks it has 4 disk drives:
> 1 internal and 3 external. The three external ones are marked "BAD".
> 
> We suspect that's it has something to do with pin 1 on CN5 (_RDY) (Does
> the "_" means active low?). This line remains low during startup.

Yep, this is a low active signal.

I've seen this problem before.  It usually idicates that either some
drive is holding ready low all the time or there is a short on the
board that is grounding ready.  Other possibilities are that the 8520
that ready goes into is blown or one of the select lines is always
being held low.  The gary chip handles this for the internal drive,
so conceivably it could be blown also...


-- 
George Robbins - now working for,	uucp: {uunet|ihnp4|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)