V9990 Central

Ports and Registers Reference

Port/Register Description R/W b7 b6 b5 b4 b3 b2 b1 b0 Port/Register
P#0 VRAM Data Port R/W VD7 VD6 VD5 VD4 VD3 VD2 VD1 VD0 P#0
P#1 Palette Data Port R/W PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 P#1
P#2 Command Data Port R/W CD7 CD6 CD5 CD4 CD3 CD2 CD1 CD0 P#2
P#3 Register Data Port R/W RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 P#3
P#4 Register Select Port W WI1 RI1 RA5 RA4 RA3 RA2 RA1 RA0 P#4
P#5 Status Port R TR VR HR BD 0 MCS EO CE P#5
P#6 Interrupt Flag Port R/W 0 0 0 0 0 CE HI VI P#6
P#7 System Control Port W 0 0 0 0 0 0 SRS MCS P#7
P#8~P#B Kanji ROM R/W Unavailable on MSX P#8~P#B
R#0 VRAM Write Address W CVWA7 CVWA6 CVWA5 CVWA4 CVWA3 CVWA2 CVWA1 CVWA0 R#0
R#1 CVWA15 CVWA14 CVWA13 CVWA12 CVWA11 CVWA10 CVWA9 CVWA8 R#1
R#2 CVWAIH 0 0 0 0 CVWA18 CVWA17 CVWA16 R#2
R#3 VRAM Read Address W CVRA7 CVRA6 CVRA5 CVRA4 CVRA3 CVRA2 CVRA1 CVRA0 R#3
R#4 CVRA15 CVRA14 CVRA13 CVRA12 CVRA11 CVRA10 CVRA9 CVRA8 R#4
R#5 CVRAIH 0 0 0 0 CVRA18 CVRA17 CVRA16 R#5
R#6 Screen Mode R/W DSPM1 DSPM0 DCKM1 DCKM0 XIMM1 XIMM0 CLRM1 CLRM0 R#6
R#7 0 C25M SM1 SM PAL EO IL HSCN R#7
R#8 Control R/W DISP SPD YSE VWTE VWM DMAE VSL1 VSL0 R#8
R#9 Interrupt R/W 0 0 0 0 0 IECE IEH IEV R#9
R#10 IL7 IL6 IL5 IL4 IL3 IL2 IL1 IL0 R#10
R#11 IEHM 0 0 0 0 0 IL9 IL8 R#11
R#12 0 0 0 0 IX3 IX2 IX1 IX0 R#12
R#13 Palette Control W PLTM1 PLTM0 YAE PLTAIH PLTO5 PLTO4 PLTO3 PLTO2 R#13
R#14 Palette Pointer W PLTA5 PLTA4 PLTA3 PLTA2 PLTA1 PLTA0 PLTP1 PLTP0 R#14
R#15 Backdrop Color R/W 0 0 BDC5 BDC4 BDC3 BDC2 BDC1 BDC0 R#15
R#16 Display Adjust R/W ADJV3 ADJV2 ADJV1 ADJV0 ADJH3 ADJH2 ADJH1 ADJH0 R#16
R#17 Scroll Control R/W SCAY7 SCAY6 SCAY5 SCAY4 SCAY3 SCAY2 SCAY1 SCAY0 R#17
R#18 R512 R256 0 SCAY12 SCAY11 SCAY10 SCAY9 SCAY8 R#18
R#19 0 0 0 0 0 SCAX2 SCAX1 SCAX0 R#19
R#20 SCAX10 SCAX9 SCAX8 SCAX7 SCAX6 SCAX5 SCAX4 SCAX3 R#20
R#21 SCBY7 SCBY6 SCBY5 SCBY4 SCBY3 SCBY2 SCBY1 SCBY0 R#21
R#22 0 0 0 0 0 0 0 SCBY8 R#22
R#23 0 0 0 0 0 SCBX2 SCBX1 SCBX0 R#23
R#24 0 0 SCBX8 SCBX7 SCBX6 SCBX5 SCBX4 SCBX3 R#24
R#25 Sprite Pattern Generator Table Base Address P1 mode R/W 0 0 0 0 SGBA17 SGBA16 SGBA15 0 R#25
P2 mode 0 0 0 0 SGBA18 SGBA17 SGBA16 SGBA15
R#26 LCD Control R/W Unavailable on MSX? R#26
R#27 Priority Control R/W 0 0 0 0 PRY1 PRY0 PRX1 PRX0 R#27
R#28 Sprite Palette Control W 0 0 0 0 CSPO5 CSPO4 CSPO3 CSPO2 R#28
R#32 Source XY Coordinates
Linear Address
Kanji ROM Address		 W SX7 SX6 SX5 SX4 SX3 SX2 SX1 SX0 R#32
SA7 SA6 SA5 SA4 SA3 SA2 SA1 SA0
KA7 KA6 KA5 KA4 KA3 KA2 KA1 KA0
R#33 0 0 0 0 0 SX10 SX9 SX8 R#33
R#34 SY7 SY6 SY5 SY4 SY3 SY2 SY1 SY0 R#34
SA15 SA14 SA13 SA12 SA11 SA10 SA9 SA8
KA15 KA14 KA13 KA12 KA11 KA10 KA9 KA8
R#35 0 0 0 0 SY11 SY10 SY9 SY8 R#35
0 0 0 0 0 SA18 SA17 SA16
0 0 0 0 0 0 KA17 KA16
R#36 Destination XY Coordinates
Linear Address		 W DX7 DX6 DX5 DX4 DX3 DX2 DX1 DX0 R#36
DA7 DA6 DA5 DA4 DA3 DA2 DA1 DA0
R#37 0 0 0 0 0 DX10 DX9 DX8 R#37
R#38 DY7 DY6 DY5 DY4 DY3 DY2 DY1 DY0 R#38
DA15 DA14 DA13 DA12 DA11 DA10 DA9 DA8
R#39 0 0 0 0 DY11 DY10 DY9 DY8 R#39
0 0 0 0 0 DA18 DA17 DA16
R#40 Transfer Dot Number XY
Linear
Line Minor, Major		 W NX7 NX6 NX5 NX4 NX3 NX2 NX1 NX0 R#40
NA7 NA6 NA5 NA4 NA3 NA2 NA1 NA0
MJ7 MJ6 MJ5 MJ4 MJ3 MJ2 MJ1 MJ0
R#41 0 0 0 0 0 NX10 NX9 NX8 R#41
0 0 0 0 MJ11 MJ10 MJ9 MJ8
R#42 NY7 NY6 NY5 NY4 NY3 NY2 NY1 NY0 R#42
NA15 NA14 NA13 NA12 NA11 NA10 NA9 NA8
MI7 MI6 MI5 MI4 MI3 MI2 MI1 MI0
R#43 0 0 0 0 NY11 NY10 NY9 NY8 R#43
0 0 0 0 0 NA18 NA17 NA16
0 0 0 0 MI11 MI10 MI9 MI8
R#44 Argument W 0 0 0 0 DIY DIX NEQ MAJ R#44
R#45 Logical Operation W 0 0 0 TP L11 L10 L01 L00 R#45
R#46 Write Mask W WM7 WM6 WM5 WM4 WM3 WM2 WM1 WM0 R#46
R#47 WM15 WM14 WM13 WM12 WM11 WM10 WM9 WM8 R#47
R#48 Font Color W FC7 FC6 FC5 FC4 FC3 FC2 FC1 FC0 R#48
R#49 FC15 FC14 FC13 FC12 FC11 FC10 FC9 FC8 R#49
R#50 BC7 BC6 BC5 BC4 BC3 BC2 BC1 BC0 R#50
R#51 BC15 BC14 BC13 BC12 BC11 BC10 BC9 BC8 R#51
R#52 Opeartion Code W OP3 OP2 OP1 OP0 AYM AYE AXM AXE R#52
R#53 Border X Coordinate R BX7 BX6 BX5 BX4 BX3 BX2 BX1 BX0 R#53
R#54 0 0 0 0 0 BX10 BX9 BX8 R#54