rm/rm380z.cpp: Split RM480Z out to its own driver with MQ2 floppy drive support #12576
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| m_maincpu->set_input_line(INPUT_LINE_NMI, state ? ASSERT_LINE : CLEAR_LINE); | ||
| m_sio->dcdb_w(state); | ||
| // give firmware ~50ms to finish initialisation before allowing first NMI | ||
| if (m_maincpu->total_cycles() > 200'000) |
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On hardware, is there some kind of handshake or something that makes this work, or is it more of a magical timing thing?
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It seems to be a magical timing thing, but I suppose with real hardware it would very unusual to start both CPUs at exactly the same time - there would naturally be at least a few seconds gap between pressing one power switch and then the other!
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Conflicts with recent ATTR_COLD changes resolved! Could somebody please merge this pull request if there are no further comments? I've tested the driver extensively and have even ported CP/M Plus to the 480Z using it (see https://github.com/RobinSergeant/cpmplus480z) :-) As there are no other 480Z emulators out there I think it would be nice to get this into MAME so that more people can use the machine. |
rb6502
changed the title
This PR adds a new driver to replace the non working 480Z fragments in the 380Z driver. As the hardware is so different I think it really belongs in a separate driver. Everything from the keyboard interface to video RAM access is different and the 480Z is generally much more complex.
I have emulated all the basic features, plus HRG and floppy drives. There are still more things to add in the future (such as cassette support), but I think it's in a good state for release now. Everything I've tested seems to work including the CP/M ram disk on drive M: (which is a good test of the bank switching).
It largely uses the existing ROM files, but I have added a new BIOS version (ROS 1.2D) for completeness.
Some screenshots (welcome disk title screen, Trains game, CP/M boot screen, and ROS/BIR):