[Simh] Unix v0 disk is an RB09 or equivalent

[khandy21yo]

Probably a reasonable solution at the rime. Who would ecer be able to fill up such a llarge disk?



-------- Original message --------
From Bob Supnik <bob at supnik.org> 
Date: 02/27/2016  11:45 AM  (GMT-07:00) 
To simh at trailing-edge.com 
Subject [Simh] Unix v0 disk is an RB09 or equivalent 
 
I've gone through the disk IO routines line by line, with this result: 
while Unix confines reads and writes to blocks <= 79999, it maps those 
blocks to the SECOND 512KW of the the disk. See the attached analysis. 
So the Unix v0 disk is an RB09 equivalent, and the RC09 on the field 
service listings is probably an RB09. The reason for the different names 
remains unexplained. (The drive was made by Burroughs - thanks to Tim 
Litt for finding the reference.)

dsksav copies side 1 to side 0, and dskres does the reverse, so side 0 
was used as a backup for the main disk image: handy if a programming 
experiment wrecked the disk image.

/Bob Supnik

_______________________________________________
Simh mailing list
Simh at trailing-edge.com
http://mailman.trailing-edge.com/mailman/listinfo/simh
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20160227/b55a039d/attachment.html>