Sony DX4, 486DX System Controller, DMA Controller, Keyboard Controller, DMA Channel Controller

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AR-B1474 User¡¦s Guide

2. SYSTEM CONTROLLER

This chapter describes the major structure of the AR-B1474 serial CPU board. The following topics are covered:

DMA Controller

Keyboard Controller

Interrupt Controller

Serial Port

Parallel Port

2.1DMA CONTROLLER

The equivalent of two 8237A DMA controllers are implemented in the AR-B1474 card. Each controller is a four- channel DMA device that will generate the memory addresses and control signals necessary to transfer information directly between a peripheral device and memory. This allows high-speed information transfer with less CPU intervention. The two DMA controllers are internally cascaded to provide four DMA channels for transfers to 8-bit peripherals (DMA1) and three channels for transfers to 16-bit peripherals (DMA2). DMA2 channel 0 provides the cascade interconnection between the two DMA devices, thereby maintaining IBM PC/AT compatibility.

Following is the system information of DMA channels:

DMA Controller 1

DMA Controller 2

Channel 0: Spare

Channel 4: Cascade for controller 1

Channel 1: IBM SDLC

Channel 5: Spare

Channel 2: Diskette adapter

Channel 6: Spare

Channel 3: Spare

Channel 7: Spare

Table 2-1 DMA Channel Controller

2.2 KEYBOARD CONTROLLER

The 8042 processor is programmed to support the serial keyboard serial interface. The keyboard controller receives serial data from the keyboard, checks its parity, translates scan codes, and presents it to the system as a byte data in its output buffer. The controller can interrupt the system when data is placed in its output buffer, or wait for the system to poll its status register to determine when data is available.

Data can be written to the keyboard by writing data to the output buffer of the keyboard controller.

Each byte of data is sent to the keyboard controller in series with an odd parity bit automatically inserted. The keyboard controller is required to acknowledge all data transmissions. Therefore, another byte of data will not be sent to keyboard controller until acknowledgment is received for the previous byte sent. The “output buffer full” interrupt may be used for both send and receive routines.

2-1

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Contents Industrial Grade 486DX/DX2/DX4 CPU Card Page Table of Contents Specifications Placement & Dimensions Bios ConsoleMemory Banks & Programming RS-485 SSD Types Supported & IndexPreface Organization Static Electricity PrecautionsIntroduction OverviewPacking List FeaturesDMA Controller System ControllerKeyboard Controller DMA ControllerInterrupt Controller Interrupt Controller1 I/O Port Address Map Hex Range DeviceI/O Port Address Map Real-Time Clock and Non-Volatile RAM TimerAddress Description Real-Time Clock & Non-Volatile RAMISA Bus Pin Assignment ISA Bus Pin AssignmentName Description ISA Bus Signal DescriptionReceiver Buffer Register RBR Serial PortTransmitter Holding Register THR DlabInterrupt Identification Register IIR Interrupt Enable Register IERLine Control Register LCR Modem Control Register MCRModem Status Register MSR Parallel PortDivisor Latch LS, MS Register AddressData Swapper Printer Status BufferPrinter Control Latch & Printer Control Swapper Overview Setting UP the SystemRS-232 Connector DB1 & DB2 System SettingSerial Port RS-485 Adapter Select JP3 & JP11Hard Disk IDE Connector CN1 Power Connector J5HDD Pin Assignment FDD Port Connector CN2 Parallel Port Connector CN3CN3 6 PC/104 Connector Pin PC/104 Connector Bus a & B CN6Pin PC/104 Connector Bus C & D CN4 IRQ 3-7, 9-12, 14 PC/104 ISA Bus Signal DescriptionAMD DX2-80 CPU Select JP1 CPU SettingCPU Voltage Select JP2 AMD 4X CPU 5x86 Select JP15CPU Clock Select JP6 & JP9 CPU Clock SettingDram Configuration Memory SettingCache RAM Size Select JP8 SIMM1LED Header J1, J2 & J4 Keyboard ConnectorBattery Setting Reset Header J7External Speaker Header J3 CRT Display Type Select JP13Page Installation PGM1474.EXE Utility DisketteWD1474.EXE WP1474.EXEBU1474.EXE Help to PGF File Display Error in PGF FileDisable the Software Write Protect Enable the Software Write ProtectWrite Protect Function Hardware Write ProtectWatchdog Timer Setting Watchdog TimerTime-Out Setting Time Factor Time-Out Period SecondsWatchdog Timer Enabled Watchdog Timer TriggerWatchdog Timer Disabled Page Solid State Disk Switch Setting2 I/O Port Address Select SW1-1 & SW1-2 OverviewSSD Firmware Address Select SW1-3 & SW1-4 DEVICE=C\DOS\EMM386.EXE X=C800-CFFFSSD Drive Number SW1-5 & SW1-6 Simulate 2 Disk DriveFlash Eprom Sram Disk Drive Name Arrangement ROM Type Select SW1-7 & SW1-8SSD Bios Select JP7 Jumper SettingROM Disk Installation SSD Memory Type Setting M1 ~ M3 & JP5Switch and Jumper Setting UV Eprom 27CxxxSoftware Programming UV Eprom 27CXXX Switch SettingLarge Page 5V Flash Disk 5V Large Flash 29FXXX Switch SettingSmall Page 5V Flash ROM Disk 5V Flash 29CXXX & 28EEXXX Switch SettingTyping DOS Command Using Tool ProgramRAM Disk Jumper SettingHardware Setting Installation D.O.CSSD Bios Setting JP7 Combination of ROM and RAM DiskO.C. Setting SW1-8 Software SettingPage Bios Setup Overview Bios ConsoleDate & Time Setup Standard Cmos SetupFloppy Setup Hard Disk SetupAdvanced Cmos Setup IDE LBA Mode IDE Block Mode TransferInternal Cache Memory ShadowAdvanced Chipset Setup Power Management Password Checking Setting PasswordAuto Configuration with Optimal Setting Auto Configuration with Fail Safe SettingBios Exit Save Settings and ExitExit Without Saving Bios SpecificationsCPU PCBPage Placement Placement & DimensionsDimensions Memory Banks & Programming RS-485 Using Memory BankCS1 CS0 SocketProgramming RS-485 Initialize COM portSend out one character Transmit Send out one character to COM1 Receive dataPage SSD Types Supported SSD Types Supported & Index10-2 Name Function Index

DX4, AR-B1474, 486DX specifications

The Sony 486DX, AR-B1474, and DX4 are notable examples of advanced computing technologies from the early to mid-1990s, a time when personal computers were rapidly evolving to meet increasing user demands. These systems played a pivotal role in shaping the landscape of modern computing.

The Sony 486DX is built around the popular Intel 80486 microprocessor, which was a significant step up from its predecessor, the 386. The 486DX featured a 32-bit architecture and introduced integrated cache memory, which greatly enhanced data processing speeds and overall system performance. Operating at clock speeds typically ranging from 25 to 100 MHz, the 486DX models provided a solid foundation for running more sophisticated software applications and advanced games of the era.

Accompanying the 486DX was the AR-B1474 motherboard, designed to maximize the potential of the 486 architecture. This motherboard featured support for up to 512 KB of level 2 cache memory, further boosting performance for data-heavy tasks. The AR-B1474 also included extensive connectivity options, with ISA slots for legacy devices, as well as support for EISA, making it compatible with a wide range of hardware peripherals. This versatility made the AR-B1474 a popular choice among builders of custom desktop PCs during its time.

The DX4, another significant milestone, built upon the 486 architecture by introducing a clock-doubling technique. By effectively allowing the processor to perform operations at up to three times its base clock speed (typically 75 or 100 MHz), the DX4 could handle even more demanding applications, thereby providing users with significant performance improvements without requiring a complete overhaul of their systems.

Both the 486DX and DX4 processors facilitated advancements in multimedia capabilities, with improved graphics rendering and audio performance that supported CD-ROMs and early gaming technologies. This made them particularly appealing to consumers looking for a versatile machine for both work and entertainment.

Overall, the combination of the Sony 486DX, AR-B1474 motherboard, and DX4 processor exemplifies a significant chapter in computing history, showcasing how hardware advancements seamlessly integrated with user needs for performance and flexibility. As these technologies laid the groundwork for future innovations, they remain noteworthy for their contributions to the evolution of personal computing.