IBM PC 300GL manual Software compatibility, Software interrupts, Machine-sensitive programs

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3.Sends the EOI

4.Waits one I/O delay

5.Enables the interrupt through the Set Interrupt Enable Flag command

Hardware interrupt IRQ9 is defined as the replacement interrupt level for the cascade level IRQ2. Program interrupt sharing is implemented on IRQ2, interrupt hex 0A. The following processing occurs to maintain compatibility with the IRQ2 used by IBM Personal Computer products:

1.A device drives the interrupt request active on IRQ2 of the channel.

2.This interrupt request is mapped in hardware to IRQ9 input on the second interrupt controller.

3.When the interrupt occurs, the system microprocessor passes control to the IRQ9 (interrupt hex 71) interrupt handler.

4.This interrupt handler performs an EOI command to the second interrupt controller and passes control to the IRQ2 (interrupt hex 0A) interrupt handler.

5.This IRQ2 interrupt handler, when handling the interrupt, causes the device to reset the interrupt request before performing an EOI command to the master interrupt controller that finishes servicing the IRQ2 request.

Software compatibility

To maintain software compatibility, the interrupt polling mechanism that is used by IBM Personal Computer products is retained. Software that interfaces with the reset port for the IBM Personal Computer positive-edge interrupt sharing (hex address 02Fx or 06Fx, where x is the interrupt level) does not create interference.

Software interrupts

With the advent of software interrupt sharing, software interrupt routines must daisy chain interrupts. Each routine must check the function value, and if the function value is not in the range of function calls, that routine must transfer control to the next routine in the chain. Because software interrupts are initially pointed to address 0:0 before daisy chaining, check for this case. If the next routine is pointed to address 0:0 and the function call is out of range, the appropriate action is to set the carry flag and initiate a RET 2 to indicate an error condition.

Machine-sensitive programs

Programs can select machine-specific features, but they must first identify the machine and model type. IBM has defined methods for uniquely determining the specific machine type. The machine model byte can be found through interrupt 15H, Return System Configuration Parameters function (AH)=(C0H).

32PC 300 GL and 300 PL

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Contents HcchM mlmiM mlni hcc mlml HcchM mlmiM mlni hcc mlml Second Edition March Contents Page Related publications PrefaceTerminology System Overview FeaturesCD-RW Adsl modems Wake on LANWake on Ring PC 300 GL and 300 PL Chip set control System board featuresIntel Pentium III microprocessor with MMX technology L2 CacheTable . Memory Configuration MB Total Memory Mem O PCI Bus IDE bus master interfaceUSB interface Video Subsystem IRQ Video subsystem resources Resource AssignmentROM RAMAudio Subsystem Integrated peripheral controller Diskette Drive InterfaceSerial ports Keyboard and mouse ports Parallel portExpansion adapters Network connectionReal-time clock and Cmos Flash EepromPhysical layout Ýdimm Rocker switchesLarge rocker switch settings Microprocessor Speed Cable connectors Connector panelSmall rocker switch settings Function 18 PC 300 GL and 300 PL USB 20 PC 300 GL and 300 PL PC 300 GL and PL desktop Physical specificationsAcoustical noise-emission values PC300 PL and GL towerHeat output AirflowPhysical specifications 24 PC 300 GL and 300 PL Power input requirements Specification Measurements Power supplyPower input Power outputUSB port Supply voltage Maximum current Tolerance Component outputsSystem board Supply voltage Maximum current Tolerance Keyboard port Supply voltage Maximum current ToleranceConnector description Output protectionVideo port pin Supply voltage Maximum current Tolerance 28 PC 300 GL and 300 PL Plug and Play System softwareFlash update utility program Configuration/Setup Utility programAdvanced Power Management APM Advanced Configuration and Power Interface AcpiSystem compatibility Hardware compatibilityHardware interrupts Software compatibility Software interruptsMachine-sensitive programs DDC2B Appendix A. Connector pin assignmentsSvga monitor connector Svga monitor port connector pin assignments Pin SignalSystem memory connector DVI-I monitor connectorDQ3 VSS DQ0DQ1 DQ2DQMB2 BA0 BA1CK1 CK0 CKE0System memory connector pin input/output Pin Signal name DQMB4# DQMB1# GNDVDD WE# CAS# DQMB0#SA0 VDD VrefGND CK2 SA0 SDAPCI connector pin assignments Pin Signal PCI connectorsDEVSEL# FRAME#IRDY# TRDY#IDE connector pin assignments Pin Signal IDE connectorsMSEN1 Diskette drive connectorDiskette drive connector pin assignments Pin Signal MSEN0Power supply connector Wake on LAN connectorsUSB port connectors Keyboard port connector pin assignments Pin Signal Mouse and keyboard port connectorsSerial port connector Mouse port connector pin assignments Pin SignalParallel port connector pin assignments Pin Signal Parallel port connectorAppendix B. System address maps System memory mapFFFE0000-FFFFFFFF Input/output address map O address map Address hex Size DescriptionLPT3 COM1 COM2LPT2 LPT1DMA I/O address map PCI configuration space map 52 PC 300 GL and 300 PL Appendix C. IRQ and DMA channel assignments IRQ channel assignmentsSystem resource DMA channel assignments Data width System resource Appendix D. Error codes Post error codesBeep codes 56 PC 300 GL and 300 PL IBM Appendix E. Notices and Trademarks58 PC 300 GL and 300 PL Bibliography 60 PC 300 GL and 300 PL PCI IndexUart