From: mjuschke@tartarus.uwa.edu.au (Michael Juschke)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: AdSCSI Micro Hostadaper trouble
Date: 16 Dec 1992 10:53:22 GMT
Organization: The University of Western Australia
NNTP-Posting-Host: tartarus.uwa.edu.au

>bjgrier@bnr.ca (Brian Grier) writes:

>> Most suitable SCSI drives are now manufactured in permanent parity enable 
>> as it is used with most PC's. It was only possible for me to get an 
>> affordable drive as there were some old stock of drives availabe at one
>> supplier. One supposedly jumpered drive I ordered turned out with enabled 
>> parity and no jumper, as it was already a newer model.

>Well is it EVEN or ODD parity that is enabled? It does make a difference.
>BTW what is suitable? Quantum, Maxtor, Seagate, Conner, and Micropolis
>drives are still all selectable for EVEN, ODD, or NO parity.

Well, it doesn't tell. What it says in the specs I have seen is a jumper
which is labled PE and it says 'parity enabled' , that's all !

Suitable is a drive in the price range below $AUS 1000 which is
low-profile and will fit into a Mega. I had no trouble finding drives with
PE jumpers in the range $1500-4000. You might have that kind of money, I don't. 

Also, I bought a Conner 60Mb harddrive which has NO PARITY JUMPER and
does NOT work ! I ordered a Quantum 85 MB which was supposed to be
usable, it turned out to be a newer model WITHOUT A PARITY OPTION.
It DID NOT WORK either !

So, NOT ALL of the drives you name are selectable, at least not in Australia.

>> Can anybody give me a convincing reason why these adapters are manufactured for
>> no parity when the world of SCSI drives (PC's) operate with enabled parity ?

>PC's are not the only users of SCSI drives. Sun, HP, DEC, and Commodore are 
>a few of the companies that make SCSI controllers that do not require parity. 
>PC's have arrived relatively late to the SCSI standard, and the PC SCSI controller
>cards I have seen have a jumper you can change from their standard parity to
>whatever you want. Besides the SCSI spec says that parity mst be selectable.
>So if what you say is true then write the PC SCSI card developers and tell
>them to follow the SCSI/SCSI II standard.

Tell this to the shops that are around here, most of them sell PC's only
or Mac's. Most shops sell SCSI's low-profile only above 300Mb. And as before,
there are so-called SCSI drives (Conner 60, Quantum 85) which DO NOt have the
jumper.

>> The other question is about the fact that I have been told that a high 
>> percentage of Micro adapters are faulty out of the box. 

>I own three host adapters and the only on I've replaced was the 1987 one 
>that does not have the correct interface drivers for the STe and TT. 
>They all worked right out of the box first time. Now the Micro host
>adapters are only used in MegaSTs, and are not useable on the keyboard
>case ST or any STe or TT, so you may be right.

Well, one of the importers here told me that they have a high percentage
of micro adapters which do not work out of the box. Maybe it's bad
transport, I don't know, you guys don't have them to get shipped over. FACT is,
mine did not work when I bought it !

>> PS. : To all third party and Atari manufacturers. Think before you build and 
>>       consider that your product is not the only thing that somebody adds to 
>>       his system.

>Think, and get the facts before you try to chastise others.


>Brian, WS1S
>Bell Northern Research
>Research Triangle Park, NC


Michael