Contents
Blue Chip Technology Ltd.
01270170.doc
APPENDIX A - NUMBERING SYSTEMS ......................................... 43
Binary and Hexadecimal Numbers ............................................... 43
Base Address Selection ............................................................... 46
APPENDIX B - PC MAPS................................................................. 47
PC/XT/AT I/O Address Map ......................................................... 47
PC/XT Interrupt Map .................................................................... 48
PC/AT Interrupt Map .................................................................... 49
DMA Channels............................................................................. 49
APPENDIX C - HOW TO USE DMA................................................. 50
The DMA Controller ..................................................................... 50
The DMA Controller Registers...................................................... 52
Mode Register.............................................................................. 52
Mask Register .............................................................................. 54
Status Register ............................................................................ 54
Clear Byte Pointer Flip Flop ......................................................... 55
DMA Transfer Start Address ........................................................ 55
Transfer Length............................................................................ 55
Page Register .............................................................................. 55
Addressing ................................................................................... 56
DMA Limitations........................................................................... 57
Programming Example ................................................................ 57