Back in 1987 Léon Bottou wrote a portable assembler, called crasm, for the 6800, 6801, 6803, 65C02, and Z80 for AmigaOS. According to a recent Freshmeat.net accouncement the code has been ported to Linux and is available as Free Software licensed under the GNU GPL. A crasm Source Forge project has also been set up for the software. It's not unusual even today to see robots using some of these older CPUs, so this assembler could come in handy for robot builders.