That's unverified for now.

Source code for tests 791401 (equivalent of VKAA) and 791404 (VKAH ??) -- https://github.com/nzeemin/bkbtl-doc/tree/master/Tests

C implementation of 1801VM1 core (converted from reverse-engineered Verilog model) -- http://zx-pk.ru/attachment.php?attachmentid=53262&d=1440679095