© 1985 ASCII CORP. / NIPPON GAKKI CO.
Page 67 of 108
© 2010-2015 Eugeny Brychkov
MSB
7 6 5 4 3 2 1 0
LSB
R#44
CR7 CR6 CR5 CR4 CR3 CR2 CR1 CR0
X=2N
X=2N+1
G4, G6
(N=0..127)
CR7 CR6 CR5 CR4 CR3 CR2 CR1 CR0
X=4N
X=4N+1
X=4N+2
X=4N+3
G5 (N=0…127)
CR7 CR6 CR5 CR4 CR3 CR2 CR1 CR0
X=N (One dot)
G7
Step 3: Select destination memory and direction from base coordinate
MSB
7 6 5 4 3 2 1 0
LSB
R#45
0 - MXD
- DIY
DIX - -
0: Right
1: Left
X transfer
direction
0: Down
1: Up
Y transfer
direction
0: VRAM
1: ExpRAM
Destination
select
Step 4: Execute the command
MSB
7 6 5 4 3 2 1 0
LSB
R#46
1 1 1 1 - - - - HMMC
cmd
Step 5: Send data and wait for completion
While command is being executed by VDP, CE bit of status register S#2 will be set to
1. When command is complete, it will be reset to 0.
When VDP sets TR bit of status register S#2 to “1” application can send next data to
the VDP color register R#44 (CLR). If TR bit is 0, then application should not send data
and wait till TR bit is set to 1 or terminate the command if needed.