More progress. Added a PC11-type paper tape reader, reused a bit of code from SIMH (console terminal stuff, EIS insns emulation etc.) and now I can run paper-tape software -- for now, it's mostly tests.

ROM CPU tests and 2 of LSI-11 CPU tests (VKAA -- basic instructions, VKAB -- EIS) are passing. FIS test is failing, but this CPU has no hardware FIS support and it's emulated in ROM; unsure if real CPU passes these or not.

MESS: МС1201.02 WIP - MAINDEC-11-DVKAA test passing

MESS: МС1201.02 WIP - MAINDEC-11-DVKAB test passing

MESS: МС1201.02 WIP - MAINDEC-11-DVKAC test failing