Xref: utzoo unix-pc.general:2027 comp.sys.att:5176
Path: utzoo!utgpu!watmath!clyde!att!chinet!les
From: les@chinet.chi.il.us (Leslie Mikesell)
Newsgroups: unix-pc.general,comp.sys.att
Subject: Re: Looks like a bug in the 7300 disk driver
Summary: even more..
Message-ID: <7425@chinet.chi.il.us>
Date: 11 Jan 89 04:44:03 GMT
References: <813@ttrde.UUCP> <1360@mtunb.ATT.COM> <513@genesis.ATT.COM>
Reply-To: les@chinet.chi.il.us (Leslie Mikesell)
Organization: Chinet - Public Access Unix
Lines: 13

>>In the UNIX-PC, the RAW -- read that "character-device" -- interface
>>to the disk directly maps transfers into user RAM.  Therefore, since
>>transfers to/from the disk are in 512 byte blocks, ya can only read
>>in 512-byte multiples.

For even more fun try writing from a buffer in a shared memory
segment -- the machine locks up competely.  (I ran into this
while trying to write a high-speed multi-process dump eventually
intended for a 3B2 tape drive.  After crashing the 3B2 by putting
the tape in streaming mode and writing too large a block, I thought
I would work the bugs out on a 3B1. Oh, well..)

Les Mikesell