Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uunet!mcsun!ukc!tadtec!tjb
From: tjb@tadtec.uucp (Tim Bissell)
Newsgroups: comp.sys.handhelds
Subject: Machine code on the HP48
Message-ID: <TJB.90Sep4133352@tadtec.uucp>
Date: 4 Sep 90 12:33:52 GMT
Sender: tjb@tadtec.uucp (Tim Bissell)
Distribution: comp
Organization: Tadpole Technology plc
Lines: 51


Hi there!

I am trying to get started writing machine code for the hp48sx.  I have
got a copy of the Sass 2.31 assembler running on a Unix box, and a
HP48SX with revision A ROMs.  I can assemble the supplied cht.s example
program, and get this in ->SYS mode:

%%HP: T(3);
{
# 1231641961231341h
# 2314412313417E47h
# C808461241h
}

The \->SYS I use is one I have is listed identically in two different articles,
and as uploaded from my 48 looks like this -- note that my checksum is
different to the checksums listed, although the text is identical:

@ \->SYS [ # 5507h / 88.5 ]
%%HP: T(3)A(D)F(.);
\<< " " + LIST\-> 2
SWAP
  START # 5193h
SYSEVAL
  NEXT # 4003h
SYSEVAL # 56B6h
SYSEVAL DROP
\>>

When I try and make a code object by recalling the list to the stack
and running \->SYS on it, an 'External' object rather than a 'Code' object
is created.  Could it be that the Sysevals in \->SYS don't work on
Rev. A ROMs?

How does one translate the output of Sass -c/-p/-pc into a form which
can be downloaded as a code object? can you just translate ASCII bytes
into binary bytes, or do you need to do some word/byte or nibble swapping?

Any help would be appreciated.  If you post suggestions etc. to me
I will summarise the results and post a "getting started in HP48 machine code"
article to this group.

Thanks in advance,

Tim.

-- 
Tim Bissell  Tadpole Technology | (tjb@tadtec.UUCP || ...!mcsun!ukc!tadtec!tjb)
Cambridge Science Park 		| "Is life worth living?              DoD#174
Cambridge ENGLAND		|  That depends on the liver"         CBR 600