AT&T 3B2/300 Technical Reference Manual page 264

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VERSION 3 COMPUTER ADDRESS SPECTRUM
NOTES:
STARTING
ADDRESS
DESCRIPTION WIDTH
Ox 00000000 READ ONLY MEMORY [(EP)ROMJ 32 BITS
Ox 00040000 FLOPPY CONTROL ST A TUS REGISTER
8 BITS
Ox 00041000 TIMER
-
Ox 00042000 NVRAM
8 BITS
Ox 00044000
CONTROL AND STATUS REGISTER (CSR) 32 BITS
Ox 00045000 FLOPPY OMA PAGE REGISTER 12 BITS
Ox 00046000
UARTA OMA PAGE REGISTER 12 BITS
Ox 00047000 UARTB OMA PAGE REGISTER 12 BITS
Ox 00048000 OMA CONTROLLER (9517) 8 BITS
Ox 00049000 UARTS (2681) 8 BITS
Ox 0004AOOO FLOPPY CONTROLLER (1793) 8 BITS
Ox 0004BOOO RESERVED (NOTE 2)
-
Ox 0004COOO FAULT REGISTER 1 32 BITS
Ox 00040000 FAULT REGISTER 2 32 BITS
Ox 0004EOOO TIME-OF-DAY CLOCK 4 BITS
Ox 0004FOOO MEMORY MANAGEMENT UNIT (MMU)
-
Ox 00200000 FEATURE CARD SLOT 1 16 BITS
Ox 00400000 FEATURE CARD SLOT 2 16 BITS
Ox 00600000 FEATURE CARD SLOT 3 16 BITS
Ox 00800000 FEATURE CARD SLOT 4 16 BITS
Ox OOAOOOOO FEATURE CARD SLOT 5 16 BITS
Ox OOCOOOOO FEATURE CARD SLOT 6 16 BITS
Ox OOEOOOOO FEATURE CARD SLOT 7 16 BITS
Ox 01000000 FEATURE CARD SLOT 8 16 BITS
Ox 01200000 FEATURE CARD SLOT 9 16 BITS
Ox 01400000 FEATURE CARD SLOT 10 16 BITS
Ox 01600000 FEATURE CARD SLOT 11 16 BITS
Ox 01800000 FEATURE CARD SLOT 12 16 BITS
Ox OlAOOOOO RESERVED 16 BITS
Ox OlCOOOOO UBUS CONNECTOR 16 BITS
Ox 02000000 MAIN MEMORY 32 BITS
Ox 06000000 BUBUS CONNECTOR 1 16 BITS
Ox OAOOOOOO BUBUS CONNECTOR 2 16 BITS
Ox OEOOOOOO BUBUS CONNECTOR 3 16 BITS
Ox 12000000 BUBUS CONNECTOR 4 16 BITS
Ox COFOOOOO HW, SW DEVELOPMENT SYSTEM
-
Ox ClOOOOOO RESERVED FOR DIAGNOSTICS -
1. All the bits are settable and clearable by software.
2. Accessing this address returns neither OT ACK nor SRDY signals.
3. 64 megabytes maximum. Actual size depends on size of memory
card (2 M/4 M/16 M) and the number of memory cards (1/2/3/4).
LEGEND:
BUBUS
CSR
DMA
NVRAM
UARTS
UBUS
Buffered Microbus
Control and Status Register
Direct Memory Access
Nonvolatile Random Access Memory
Universal Asynchronous Receiver /Transmitters
Unbuffered Microbus
Figure 3-4: Version 3 Computer Address Spectrum
SIZE
128 KILOBYTES
1 BYTE
-
2 KILOBYTES
4 BYTES (NOTE 1)
-
-
-
-
16 BYTES
2 BYTES
-
4 WORDS
1 WORD
-
-
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
2 MEGABYTES (MAXIMUM)
64 MEGABYTES (NOTE 3)
64 MEGABYTES
64 MEGABYTES
64 MEGABYTES
64 MEGABYTES
1 MEGABYTE
1 MEGABYTE
FUNCTIONAL DESCRIPTION 3-11