Compaq EX Series, EXS Series manual ICH Fixed I/O Registers, Port Register Name

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6.1.4ICH Fixed I/O Registers

Port	Register Name
00h, 02h, 04h, 06h	Channel 0, 1, 2, 3 DMA Base & Current Address Regsiter
C0h, C4h, C8h, CCh	Channel 4, 5, 6, 7 DMA Base & Current Address Register
01h, 03h, 05h, 07h	Channel 0, 1, 2, 3 DMA Base & Current Count Register
C2h, C6h, Cah, CEh	Channel 4, 5, 6, 7 DMA Base & Current Count Register
10h-1Fh	Aliased at 00h-0Fh
20h	Master PIC ICW1 Init. Cmd Word 1 Register
	Master PIC OCW2 Op Ctrl Word 2 Register
	Master PIC OCW3 Op Ctrl Word 3 Register
21h	Master PIC ICW2 Init. Cmd Word 1 Register
	Master PIC ICW3 Init. Cmd Word 1 Register
	Master PIC ICW4 Init. Cmd Word 1 Register
	Master PIC OCW1 Op Ctrl Word 3 Register
24h-25h, 28-29h,	Aliased at 20h-21h
2Ch-2Dh, 30h-31h,
34h-35h, 38h-39h,
3Ch-3Dh
40h	Counter 0 Interval Time Status Byte Format
	Counter 0 Counter Access Port Register
41h	Counter 1 Interval Time Status Byte Format
	Counter 1 Counter Access Port Register
42h	Counter 2 Interval Time Status Byte Format
	Counter 2 Counter Access Port Register
43h	Timer Control Word Register
	Timer Control Word Register Read Back
	Counter Latch Command
50h-53h	Aliased at 40h-43h
61h	NMI Status and Control Register
70h	NMI Enable Register
	Real-Time Clock (Standard RAM) Index Register
71h	Real-Time Clock (Standard RAM) Target Register
72h	Extended RAM Index Register
73h	Extended RAM Target Register
74h-75h	Aliased at 70h-71h
76h-77h	Aliased at 72h-73h or 70h-71h
81h, 82h, 83h	Channel 2, 3, 1 DMA Memory Low Page Register
84h-86h, 88h	Reserved Page Registers
89h, 8Ah, 8Bh	Channel 6, 7, 5 DMA Memory Low Page Register
8CH-8Eh	Reserved Page Registers
8Fh	Refresh Low Page Register
91h-9Fh	Aliased at 81h-8Fh
(except 92h)
92h	Fast A20 and INIT Register

continued

Compaq Deskpro EX and Deskpro EXS Series of Personal Computers 6-3

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Contents Maintenance & Service Guide Maintenance & Service Guide Maintenance & Service Guide Contents Removal and Replacement Procedures Specifications Symbols and Conventions About this GuideTechnician Notes Locating Additional Information Product Description ChapterComputer Features Front Panel Controls and LEDsComponent/Function Component Rear Panel ConnectorsDrive Positions Reference Drive Bay ConfigurationSerial Number Location Spare Parts System Unit Spare Part Warranty Description Number TierMass Storage Devices Cables Standard, Memory, and Expansion Boards Miscellaneous Plastics Kit Miscellaneous Screw Kit not illustrated Keyboards not illustratedShipping Boxes not illustrated Miscellaneous Parts not illustratedDocumentation and Software not illustrated Description Spare Part NumberElectrostatic Discharge Information Removal & Replacement PreliminariesGenerating Static Relative Humidity Event 55% 40% 10%Personal Grounding Methods and Equipment Preventing Electrostatic Damage to EquipmentGrounding Workstations Method VoltageGeneral Cleaning Safety Precautions Routine CareRecommended Materials and Equipment Cleaning the Computer Case Cleaning the KeyboardCleaning the Monitor Cleaning the Mouse Service ConsiderationsPower Supply Fan Tools and Software RequirementsCables and Connectors Lithium Coin Cell BatteryHard Drives Disassembly Sequence Chart Removal and Replacement ProceduresDisassembly Preparation Feet Installation Cable Lock Access Panel Front Bezel Power Button Subpanel and Bezel Blanks Power Switch Assembly Drive Positions Using the Cable-Select Feature with Ultra ATA Devices Removing an Internal 3.5-Inch Hard Drive Removing an External 5.25-Inch Drive Removing an External 3.5-Inch Drive Page Expansion Board Slots Expansion BoardsRemoving a PCI Expansion Board Installing a PCI Expansion Board Page Memory Module Installation System MemoryDIMMs Page Graphics Cards Installing a GPA/AIMM Card 24Removal & Replacement Procedures Removing an AGP Card AGP Card with a Type I Retention Mechanism13.3 GPA/AIMM Card with a Type 2 Retention Mechanism AGP Card with a Type 2 Retention Mechanism Standard AGP Expansion Card Processor 30Removal & Replacement Procedures System Board Battery Chassis Fan Assembly Power Supply Connectors and Jumpers Connectors and JumpersClearing Cmos Disabling or Clearing the Power-On and Setup Passwords Hard Drive Jumper Settings Seagate, Quantum, and Western DigitalDefinition Seagate Quantum Western Digital Definition J50 J48 J46 J44 J42 MaxtorSpecifications SpecificationsSystem System DMA System InterruptsHardware IRQ System Function Hardware DMA System FunctionPort Register Name ICH Fixed I/O RegistersICH Fixed I/O Registers Port Register Name Size Memory Address System Function System Memory MapMB Diskette Drive Drives10.0 GB 15.0 GB Ultra ATA Hard Drives48X Max CD-ROM DrivesScroll Mouse Compaq KeyboardColor Depth Mode Bits/pixel Refresh Rate Hz Supported Graphics ResolutionsIntel 3D Graphics NVIDIA M64 ProIndex 2Index