[comp.sys.amiga] Amiga 500 external floppy disk failure

finkel@TAURUS.BITNET (08/12/88)

>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:
.
. [stuff deleted]
.
>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.
>Adding a 4K7 pull-up resistor 4K7 doesn't.
>
>If anyone has a hint on where to look or what to do, we are greatfull.
>
>                    Andrew
>
>--
>Hans Zuidam                                    E-Mail: hans@nlgvax.UUCP
>Philips Telecommunications and Data Systems,   Tel: +31 40 892288
>Project Centre Geldrop, Building XR
>Willem Alexanderlaan 7B, 5664 AN Geldrop       The Netherlands

Your problem is probably a bad 8520 chip. I ran into the same problem
when I was hooking my external 5.25" and 3.5" drives. I managed to blow
up my 2 8250 chips. ( after the first blew, I swapped them inside. An external
drive was more important to me than the printer port. Then I blew the second...)
Fortunately, they are only partly bad. As a result, I don't have a system
clock, ( it's frozen! ), and I can't print ( one of the output bits is stuck ).

BTW, commodore! - I can't get those chips in Israel, although I've been
tring to get them for more than 4 months! How long will I have to put
'setclock opt load' on my makefile before each compilation??


Udi

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