DEC document AA-L619A-TK

Pete Turnbull pete at
Sat Nov 29 08:20:51 CST 2014

On 29/11/2014 13:56, Mouse wrote:
>>> I went looking for MSCP docs and found a PDF holding scans of a copy
>>> of version 1.2 (April, 1982) of DEC document AA-L619A-TK [...]
>>> I don't know where I got the PDF; [...]
>> The original can be found here...
> Ah!  Thank you.  Yes, the l619atk.pdf there is bit-identical to the PDF
> I started with.

I'm not sure what you're looking for but I know of three MSCP documents 
which were at one time hard to find.  However I acquired copies several 
years ago, scanned them, and made them available.  They are:

MSCP Basic Disk Functions Manual			AA-L619A-TK, Version 1.2, First 
Edition April 1982

Storage Systems Diagnostics and Utility Protocol 	AA-L620A-TK 	April 1982

Storage System Unibus Port Description 			AA-L621A-TK 	April 1982

Collectively they make up the UDA50 Programmer's Documentation Kit, 
published by Digital Equipment Corporation, Part No. QP-905-GZ.  There 
are three documents in the set, which are useful (if not essential) to 
anyone programming for DEC's RQDX controllers and other MSCP or TMSCP 
controllers, as well as the UDA50. Don't be put off by the "Unibus" in 
the title of the third; it's applicable to QBus systems as well.

If you can't find them all, they are (temporarily) back at


Pete Turnbull

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