Interesting topic.
I've fixed a couple of the many bugs in MAME's emulation of the laser500 etc.
- The new character generator has been added, replacing the old inaccurate one.
- A language selection feature has been added: English (default), French, German.
- The non-working cursor keys have been fixed.
These will be in the next release (0.205) due out on the 26th of this month.
There's still plenty of other bugs, for example if you select the new language then choose the Reset option, it crashes. So, after choosing the new language, you have to quit and restart the emulator.
I do not possess either a machine or any manuals or software, so if you guys want other things fixed, you'll have to supply me with at least full manuals.