| |
|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| $FF00 (R/W) | |
Timer 1 High-Byte |
| $FF01 (R/W) | |
Timer 1 Low-Byte |
| $FF02 (R/W) | |
Timer 2 High-Byte |
| $FF03 (R/W) | |
Timer 2 Low-Byte |
| $FF04 (R/W) | |
Timer 3 High-Byte |
| $FF05 (R/W) | |
Timer 3 Low-Byte |
| $FF06 (R/W) | CR1 |
TEST |
ECM |
BMM |
DEN |
RSEL |
YSCROLL |
| $FF07 (R/W) | CR2 |
REVERSE |
PAL/NTSC |
STOP |
MCM |
CSEL |
XSCROLL |
| $FF08 (R/W) | |
Keyboard Input Latch |
| $FF09 (R/W) | IRQST |
IRQ |
ICNT3 |
unused ¹ |
ICNT2 |
ICNT1 |
ILP |
IRST |
unused ¹ |
| $FF0A (R/W) | IRQEN |
unused ¹ |
ECNT3 |
unused ¹ |
ECNT2 |
ECNT1 |
ELP |
ERST |
RST8 |
| $FF0B (R) | RASTER |
Raster Counter bits 7-0 |
| $FF0B (W) | RSTCMP |
Raster Comparator bits 7-0 |
| $FF0C (R/W) | |
unused ¹ |
Cursor Position bits 9-8 |
| $FF0D (R/W) | |
Cursor Position Low-Byte |
| $FF0E (R/W) | |
Channel 1 Frequency Low-Byte |
| $FF0F (R/W) | |
Channel 2 Frequency Low-Byte |
| $FF10 (R/W) | |
unused ¹ |
Chan. 1 Freq. bits 9-8 |
| $FF11 (R/W) | |
D/A mode |
C2 noise |
C2 square |
C1 enable |
Volume (0-8) |
| $FF12 (R/W) | |
unused ¹ |
Bitmap Address (A15-A13) |
CHARROM |
Chan. 2 Freq. bits 9-8 |
| $FF13 (R/W) | |
Charset Address (A15-A10) |
1 MHz |
ROM |
| $FF14 (R/W) | |
Video RAM Address (A15-A11) |
unused ¹ |
| $FF15 (R/W) | B0C |
unused ¹ |
Luma |
Chroma |
| $FF16 (R/W) | B1C |
unused ¹ |
Luma |
Chroma |
| $FF17 (R/W) | B2C |
unused ¹ |
Luma |
Chroma |
| $FF18 (R/W) | B3C |
unused ¹ |
Luma |
Chroma |
| $FF19 (R/W) | EC |
unused ¹ |
Luma |
Chroma |
| $FF1A (R/W) | |
unused ¹ |
V. RAM Pos (A9-A8) |
| $FF1B (R/W) | |
Video RAM Position (A7-A0) |
| $FF1C (R/W) | |
unused ¹ |
VSCAN8 |
| $FF1D (R/W) | |
Vertical Scan Position Low-Byte |
| $FF1E (R/W) | |
Horizontal Scan Position |
| $FF1F (R/W) | |
unused ¹ |
Flash Counter |
Vertical Character Scan Position |
| $FF3E (W) | ROMEN |
unused |
| $FF3F (W) | RAMEN |
unused |