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Joined: May 2009
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J
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Originally Posted By shattered
Emulating actual DVK series would require changes to T11 core -- their microprocessors (1801VM1, 1801VM2 and 1801VM3) are ISA-compatible but have subtle differences.


Now that (almost?) all of the CPU cores have been converted to proper modern devices, implementing device-specific opcodes should be as simple as abstracting those opcodes behind member functions and then overriding them in a child class.

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S
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EIS instruction set would be the first to add, since vm2 has it built-in and ROM code relies on that.

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The 11 had a lot of CPU variants and instruction set extensions -- https://sourceware.org/binutils/docs/as/PDP_002d11_002dOptions.html

So T11's one is "baseline" + "Limited EIS" + "MxPS"; full EIS also has ASH, ASHC, MUL and DIV.

1801VMx extensions are briefly described here -- http://pdp-11.ru/mybk/doc/PDP11.TXT, there's also a full technical manual.

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Hey, someone does actually use ie15 driver to play Tetris smile Tetris itself runs in SIMH, though.

https://www.reddit.com/r/MAME/comments/8l0jiq/mame_mess_any_way_to_hide_the_row_of_words_and/

https://www.youtube.com/watch?v=xrZYJ5Bn-xg

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