I have returned to the MDI view for this project which makes life easier when it comes to putting in debugging tools. For the moment all there is is a palette and tile viewer, but I hope to add some helpful utilities - and work out a way to tie the new Brass and an emulator together for debugging assembly programs.
I've extended the SG-1000 emulation some way towards the SC-3000 (Sega Game 1000 vs. Sega Computer 3000) which has mainly involved adding keyboard emulation. The result is the ability to run Sega BASIC, and so you get the obligatory program that everyone writes sooner or later...
There is no tape drive emulation, and I'd like to ideally emulate the SF-7000's floppy drive and disk BASIC, but don't quite follow the datasheets I've read thus far (or rather, how everything is tied together).
In the first screenshot you might have noticed that the video output window has "Altered Beast (h) [A]" in the caption. I've added ROM library support, and am currently using the data from the .romdata files arranged by Maxim for his SMS Checker utility. As well as identify a name, there is a more important reason to use the database - it can identify dodgy dumps and be used to correct them (in this case, Altered Beast has an additional header - hence the (h) - that needs to be removed).