Цитата:
The original version of "The MSX Red Book" documented the VDP ports associated to I/O addresses 98H and 99H, which are prevalent on most machines, but it is completely deprecated by MSX standard that foresees VDP expansions, which must use different I/O mapping to avoid conflicts with internal VDP. The MSX-BIOS contains two addresses that must be read to determine where the VDP read and write ports are mapped. These addresses are 0006H (read ports) and 0007H (write ports). On MSX, VDP has only two ports mapped. On MSX2, MSX2+ and turbo R, VDP has six ports mapped.
Но по ходу пьесы получилось все несколько иначе:)