4 Dec
2014
4 Dec
'14
12:38 p.m.
From: Lars Brinkhoff
Sent: Thursday, December 04, 2014 3:21 AM
Johnny Billquist <bqt at update.uu.se> writes:
> As far as I can recall, the TOAD-1 is not
compatible with the
> KL10B. I don't remember what the differences were, but I understood
> that TOPS-20 had to be modified in an incompatible way to run on it.
Right, it's not entirely compatible in executive
mode. But it is in
user mode (well, probably apart from some minor details).
The biggest detail in user mode is that the entire 30-bit address space
is available to user programs, where the Model B KL-10s provided a 22-bit
physical address and a 23-bit virtual (in TOPS-20 from v4 and in Tops-10
v7.04).
The user model is easily seen in TOPS-20 v7+ when invoking DDT: There is
a switch on the DDT command /USE-SECTION, the value of which is limited on
the KL to section 37 (octal), but can be up to 7776 on the Toad-1.
(Section 7777 is a magic value in the Toad architecture.)
The Toad-1 Architecture Reference Manual is available via anonymous FTP in
PDF, Postscript, and TeX DVI formats at Toad-1.LivingComputerMuseum.org,
in the directory <DOCUMENTATION.TOAD>. Remember to specify "tenex" or
"type l 8" for the PDF or DVI files.
Rich
Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134
mailto:RichA at LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/