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- Path: hpmde1.emw.ericsson.se!emwnie
- From: emwnie@emw.ericsson.se (Linus Nielsen)
- Newsgroups: comp.sys.amiga.networking
- Subject: Re: 8520 circuts
- Date: 23 Jan 1996 06:40:05 GMT
- Organization: Ericsson
- Message-ID: <4e1vs5$lar@erinews.ericsson.se>
- References: <1092.6595T1228T1829@mailbox.swipnet.se>
- NNTP-Posting-Host: hpmde1.emw.ericsson.se
- X-Newsreader: TIN [version 1.2 PL2]
-
- Torbj÷rn Aronsson (Torbjorn.Aronsson@mailbox.swipnet.se) wrote:
- : Hi all networking people...
-
- : I'm not one of you... :( That why i have a question for all who might help me
- : out here...
-
- : I have problems with ParBench(ParNet), when i read he doc files i began to worry
- : about my 8520 chip's. I have tested my printer on both my Amiga's and all
- : diskdrive activity is working allright, COULD it be a 8520 who's busted up even
- : if all seems to work as it should?
-
- : I have a switchbox who's screwed my 8520 chip's up once, but from that misstake
- : i have learned to switch both of the computer's of before i use the darned box
- : again... should a box behaive like this and screw 8520 chip's or are this boxe's
- : constructed for PC computer's that don't have this easyly brakeable chip's?
-
- : And i have tested Parnet with 2 different cables.
-
- : Parnet *HAVE* worked fine untill a couple of months ago... ???!!!???
-
- The 8 data bits of the parallel port and the _STROBE goes to one 8520 and the
- _ACK, BUSY, POUT and SEL goes to the other. If one of the _ACK, BUSY, POUT and
- SEL pins is broken the printer might work but not ParNet, as ParNet probably
- changes the direction of these pins.
-
- You could always try to swap the two 8520's and see if other problems show up.
-
- I don't know what Amiga model you have, but on my A500 the 8520's are called U7
- and U8. If you swap the chips and you get problems with the step motor or strange
- disk I/O errors, then it is probably U7 that is broken. If you get problems with
- disk changes or with the power LED, then U8 is your problem.
-
- Just some guesses looking at the A500 schematics, but worth a try.
-
- /Linus
-