Asm48 - an 8048 cross assembler
Original Version 0.1 Version 0.1pre January 29, 2003 by David Hovemeyer daveho@cs.umd.edu
Enhanced Version 0.4.1 April 14, 2013 by Adventure Vision Development Team of MEGA http://www.adventurevision.net main enhancements by JustBurn; OSX and multiplatform by sy2002
Version Status: 0.4.1 is stable
Asm48 is an assembler for the Intel 8048 family of microcontrollers. It is free software; you may use, modify, and redistribute it according to the terms specified in the various source files.
In case you don't know, the Intel 8048 family was one of the very first commercially successful microcontroller product lines. You can find them in an enormous range of devices, such as cars, computer keyboards, industrial equipment, etc. Members of the 8048 family include the 8021, 8035, 8038, 8039, 8040, 8048, 8049, 8050, 8748, and 8749. (I believe the 8041 and 8042 are also in the same general family, although I think the instruction encodings are somewhat different, and thus I wouldn't necessarily expect this assembler to support those chips.)
You can find the 8048 in various game systems as the Magnavox Odyssey^2 and the Entex Adventure Vision and certain arcade video games.
This product includes software developed by the University of California, Berkeley and its contributors.
The file "ihex.c" was written by Paul Stoffregen.
The file "8039dasm.c" was written by Michael Cuddy, and was shamelessly stolen from the MAME/MESS project.
The multiplatform package "asm48-0.4.1-executables-and-src-win-linux-osx.zip" contains executables for Windows, Linux and OSX, so just unzip, choose the right subdirectory and start working.
The sources and the makefile are tested to compile under Windows, Linux and OSX - normally without requiring any changes, since the makefile autodetects the platform.
You need:
Windows:
Recommended to compile using MSYS' Bournce Shell, since it already contains the GNU Compiler Collection as well as FLEX and BISON. Use the graphical installer and install MINGW together with MSYS as described here: http://www.mingw.org/wiki/Getting_Started
Linux:
Use your package manager to install FLEX and BISON.
OSX:
Install XCode plus the optional command line tools, which already contain FLEX and BISON.
Just run the command "make". There are a couple configurable options in the Makefile you might want to change. I assume you have flex and bison available on your system. You should be able to use other lex and yacc variants, although you might need to change the Makefile a bit.
The resulting executables are called "asm48" and "8039dasm". They are the assembler and disassembler, respectively.
To a large extent, I've tried to follow the assembly syntax described in the Intel 8048 user manual. However, I've made some gratuitous changes:
These directives are allowed:
.equ IDENTIFIER, VALUE .org VALUE .org VALUE, FILL-VALUE .db VALUE .db VALUE, VALUE, ... .db accepts forward labels .dbr same as .db but with reverse bit order .dw 16bit VALUE(S)
.include "FILENAME" for including assembly files .incbin "FILENAME" for including binary files
conditional directives .if, .ifdef, .ifndef, .else, .endif
message directives: .message, .warning, .error
.exit for end-of-assembly .set for conditionals
$ symbol for current offset, e.g. for doing things like "jmp $ + 3" % for modulo, e.g. for doing things like ".equ 50 % 7" ~ for flipping bits ==, !=, =, &&, || for boolean logics
Instruction immediates now also accept 8-bit negative values
expression unary <: get lo byte of word; > get hi byte
The special symbol ".here" may be used to refer to the address of the current instruction.
Values may be expressions using the standard arithmetic operators ("+", "-", "*", "/"), as well as left and right shifts ("<<" and ">>"), bitwise "&" (and) and "|" (or), and bitwise complement (the unary "~" operator). All expressions are evaluated using host platform ints. Operator precedence follows the equivalent C operators.
If you actually use this assembler, please send me an email at daveho@cs.umd.edu. I wrote it on a lark[*], and given how crufty and ancient the 8048 is, I'd be surprised and amused to find out that someone else was interested in writing code for it. I will also happily accept bug fixes and new features.
There are almost certainly bugs in this software, so use at your own risk. I accept absolutely no responsibility for any consequences resulting from the use of this software.
If you do decide to use the assembler, you are STRONGLY ADVISED to run your assembled code through the included disassembler to check that the assembler output looks reasonable.
Have fun!
[*] It was really hard to get it to stand still.
Dave did a great job. His version 0.1 of the assembler from 2003 already worked like a charm. We just added plenty of new directives, and features and fixed some minor bugs to make the assembler usable for larger projects.
Now, our version 0.4.1 from 2013 can be considered as stable and as truely multiplatform, since it runs and compiles on Windows, Linux and OSX.
The 8048 is a really cool piece of hardware, and it is fascinating what you can do with such a far more than 30 years old CPU. If you are into the demo scene, have a look at our 8048 Adventure Vision demo at http://www.pouet.net/prod.php?which=61201 or visit the "Making Of" Homepage at http://www.adventurevision.net/. You'll also find an Adventure Vision 8048 Emulator there.