From BASIC-G Manual[1983/3].

I/O PORT

Z80CTC

00h
Channel #1: SIO Int.
01h
Channel #1: Peripheral Timer
02h
Channel #2: SIO Clock Generator
03h
Channel #3: VDP Blnaking(Frame) Interrupt

VDP TMS9918A

11h
Status port
11h
Screen base address & Control port
11h
VRAM Address port
10h
Data Read port
10h
Data Write port

Sound Generator SN76489AN

20h
Control

Keyboard

30h
row#0
31h
row#1
32h
row#2
33h
row#3
34h
row#4
35h
row#5
36h
row#6

Joypad/Attack Switch

37h
Joypad Direction Input

RESET/HALT Key

50h
Reset/Halt Key data port(Bit 7)

Cassette tape recorder

50h
Output port(Bit 0)
50h
Input port(Bit 0)
50h
Remote port(Bit 1)

Pararrel Out

40h
DATA
50h
STROBE(Bit 0)
50h
BUSY(Bit 1)