On May 5, 11:37, Daniel A. Seagraves wrote:
> [Adding RX50 to the Supnik emulator...]
>
> Yeah, it'd be a Lot Of Work(tm).
It certainly would. Even the RT-11 driver (which is about the simplest
I've seen) is fairly complex.
> Those talk MSCP, and there's little/no documentation on how it works.
> (I think...)
It's basically a message-passing protocol, unlike most of the earlier DEC
disk stuff where you can poke the hardware registers to "make things
happen". To oversimplify, with MSCP you make a message containing
instructions, put it in a memory buffer somewhere, tell the controller it's
there, and it does the rest with DMA, returning a response message.
The relevant documentation is "MSCP Basic Disk Functions Manual",
AA-L619A-TK, and "Storage System Diagnostics And Utility Protocol",
AA-L620A-TK, which in turn are parts of the UDA50 Programmer's
Documentation Kit (QP-905-GZ). My copy is version 1.2, April 1982.
It's not good bedtime reading; the plot's a bit too convoluted and the
characterisation is weak :-)
--
Pete Peter Turnbull
Dept. of Computer Science
[remove indy. from email address to reply] University of York
Received on Wed May 06 1998 - 07:30:46 BST