Firmware from ec1841's XT-HDC (i8089 version; there was also a Z80 one) -- http://www.emuverse.ru/downloads/computers/ES-184x/firmware/ES-1841-KZHD.zip

There's no tech manual or schematics but here's a photo -- http://fotki.yandex.ru/users/shattered/view/642515?page=0

Disassembly looks sane but I never saw i8089 assembly before smile
Quote
00000000: 31 30 00 80 movi gb, 8000
00000004: D1 30 08 84 movi cc, 8408
00000008: 0A 4D 18 40 movbi [gb].18, 40
0000000C: 28 20 30 addbi gb, 30
0000000F: 08 30 3E movbi ga, 3e
00000012: A0 00 wid 8, 16
00000014: 60 00 xfer
00000016: 68 30 06 movbi bc, 06
00000019: 28 20 D0 addbi gb, d0
0000001C: 48 30 00 movbi gc, 00

Last edited by shattered; 02/21/14 07:55 PM.