ROM Subsystem
The ROM subsystem has a 32K by 16-bit arrangement consisting of
two 32K by 8-bit ROM/EPROM modules. The odd and even address
codes reside in separate modules. The top of the first megabyte and
the bottom of the last megabyte address space is assigned to ROM
(hex OF0000 and hex FF0000). Parity checking is not done on ROM.
BIOS has been provided in this subsystem.
RAM Subsystem
The RAM subsystem starts at address hex 000000 of the 16M address
space. It consists of either 640KB or 1MB in the form of 256K or 64K
by l-bit RAM modules. Memory refresh forces one memory cycle
every 15 microseconds through channel 1 of the timer/counter. The
following functions are performed by the RAM initialization program:
• Write operation to any memory location.
• Initialization of channel 1 of the timer/counter to the rate
generation mode (15 microseconds).
Note:
Memory can be used only after being accessed or refreshed eight
times,
20
Chapter 6: Appendix
Содержание Apex 386SX/20
Страница 1: ...PEER 2030 2 O M H z 3 8 6 S X S Y S T E M U ser s Manual ...
Страница 15: ...Chapter 1 System Overview ...
Страница 38: ...Chapter 2 Setting Up Your System ...
Страница 43: ...Figure 2 2 The Location of W9 80386SX and 80387SX Chapter 2 Setting Up Your System 5 ...
Страница 48: ...Figure 2 6 512KB Total Onboard System Memory 10 Chapter 2 Setting Up Your System ...
Страница 49: ...Figure 2 7 640 KB Total Onboard System Memory Chapter 2 Setting Up Your System 11 ...
Страница 50: ...Figure 2 8 1 MB Total Onboard System Memory 12 Chapter 2 Setting Up Your System ...
Страница 51: ...Figure 2 9 1 5 MB Total Onboard System Memory Chapter 2 Setting Up Your System 13 ...
Страница 52: ...Figure 2 11 2MB Total Onboard System Memory B 14 Chapter 2 Setting Up Your System ...
Страница 53: ...Figure 2 12 3MB Total Onboard System Memory Chapter 2 Setting Up Your System 15 ...
Страница 54: ...Figure 2 13 4MB Total Onboard System Memory 16 Chapter 2 Setting Up Your System ...
Страница 55: ...Figure 2 14 5MB Total Onboard System Memory Chapter 2 Setting Up Your System 17 ...
Страница 61: ...Chapter 3 Operating Your System ...
Страница 80: ...Chapter 4 Keyboard ...
Страница 90: ...Chapter 5 Troubleshooting ...
Страница 98: ...Appendix ...
Страница 102: ...Figure 6 3 Connecting a Floppy Disk Drive Figure 6 4 Connecting a Floppy Disk Drive to an FDC Card 4 Chapter 6 Appendix ...
Страница 103: ...Figure 6 5 Connecting a Hard Disk Drive Figure 6 6 Connecting a Hard Disk Drive to an HOC Card Chapter 6 Appendix 5 ...
Страница 123: ...Chapter 7 Glossary ...