Appendix C. System Address Maps; System Memory Map; I/O Address Map - IBM 6339 User Manual

Appendix C. System address maps

System memory map

Table 1. System memory map
Address range Address range (hex)
(decimal)
0 K – 512 KB 00000 – 7FFFF
512 K – 639 KB 80000 – 9FBFF
639 K – 640 KB 9FC00 – 9FFFF
640 K – 767 KB A0000 – BFFFF
768 K – 800 KB C0000 – C7FFF
800 K – 896 KB C8000 – DFFFF
896 K – 1 MB E0000 – FFFFF
1 MB – 16 MB 1000000 – FFFFFF
16 MB – 4096 MB 10000000 – FFDFFFFF
FFFE0000 – FFFFFFFF

I/O address map

Table 2. I/O address map
Address range (hex)
0000 – 000F
0010 – 001F
0020 – 0021
0022 – 003F
0040 – 0043
0044 – 00FF
0060
0061
0064
0070, bit 7
0070, bits 6:0
0071
© Copyright IBM Corp. 2001
The following charts represent how the hard disk stores different types of
information. Address ranges and byte sizes are approximate.
The first 640 KB of system board RAM is mapped starting at address hex 00000000.
A 256-byte area and a 1 KB area of this RAM are reserved for BIOS data. Memory
can be mapped differently if POST detects an error.
The following table lists resource assignments for the I/O address map. Any
addresses that are not shown are reserved.
Size (bytes) Description
16 DMA 1
16 General I/O locations, available to PCI bus
2 Interrupt controller 1
30 General I/O locations, available to PCI bus
4 Counter/timer 1
28 General I/O locations, available to PCI bus
1 Keyboard controller byte, reset IRQ
1 System port B
1 Keyboard controller, CMD/ATAT byte
1 bit Enable NMI
6 bits Real-time clock, address
1 Real-time clock, data
Size Description
512 KB Conventional
127 KB Extended conventional
1 KB Extended BIOS data
128 KB Dynamic video memory display cache
32 KB Video ROM BIOS (shadowed)
96 KB PCI space, available to adapter ROMs
128 KB System ROM BIOS (main memory shadowed)
15 MB PCI space
4080 MB PCI space (positive decode)
128 KB System ROM BIOS
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