Date: Thu, 21 Feb 1991 17:07 CST
Subject: Re: HP48 Questions
Organization: Digital Equipment Corporation
Lines: 59

Your questions regarding information for machine language programming
are similar to some that I asked, and which got virtually no response from
the net.

So, let me share with you my recent experiences.

To my knowledge there is no official documentation or books which describe
how to do ML programming on the HP48SX.  Here are some sources of
information that have served me well.

First, check out Alonzo Gariepy's notes on the
Saturn processor, which is the processor HP used in the 28 and also in the
48SX.  This will give you a decent introduction to the instruction set and the
basic architecture of the processor.

Then, you should read Alonzo Gariepy's notes on doing ML programming on
the HP48SX.   These notes provide some useful information, and give some
decent examples of how to do things.

Next, I recommend you take a look at the internals description by Derek
Nickel.
This gives a decent explanation of the different data types used
in the 48SX, and how they are each represented.  Of all the internals
lists that
have been posted recently, I believe that his has the best descriptions of
the various object types, their prologs and how they are stored.

Next, I recommend that you get the list of internal addresses that Jake Schwartz
recently posted to the net.  This gives a good description of all (?) the known
internal addresses and what they do.

Finally, I suggest you get the Star assembler described in note 132.  After
reading the README. file and the STAR.REF files which come as part of the Star
assemlber, you should have a pretty decent feel for how to program the 48SX.
STAR was written by Jan Brittenson, and he has put in a good effort to make it
fairly transportable.  I was able to compile and run it on a VAX/VMS system
without requiring much effort on my part.

Lastly, let me make one more suggestion.  READ THE DOCUMENTS I HAVE
MENTIONED ABOVE, in the order I have specified them.  Alonzo's notes will
give you a decent foundation regarding the architecture of the SATURN processor
and the instruction set.   Derek's notes will give you a good foundation
in the object types and how the 48SX stores information internally.
After reading
these documents, I have been able to undertake a fairly non-trivial ML
project,
the fruits of which will appear in this conference shortly, with luck.

I hope that helps.

>>>Joe

P.S. All of the documents mentioned above are available on Wayne's mail server;
a service that I highly recommend.  Information regarding Wayne's mail
server has appeared in this conference recently.