VL-486-4 Reference Manual
Register Descriptions – 57
Register Descriptions
Introduction
This chapter lists all the user-programmable registers on the VL-486-4 CPU card. Programming
details are included for non PC/AT registers only, information on the standard PC/AT registers
can be found in the The Programmer’s PC Sourcebook or The Undocumented PC listed in
“Other References” on page v. Information on the registers internal to the CPU chip can be
found in the TI486SXLC2 data book.
Register Summary
The tables in this section list all programmable registers on the VL-486-4 CPU card. They are
organized in the following groups:
Table 32: Programmable Registers
Registers
Page
DMA 1 Controller
64
DMA 2 Controller
65
DMA Page
65
COM1 Serial Port
66
COM2 Serial Port
66
LPT1 Parallel Port
67
82C721 Configuration
67
Interrupt Controller (Master)
69
Interrupt Controller (Slave)
69
Counter/Timer
70
VersaLogic Registers
70
CIO Chip
70
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