LTP1 should use IRQ7.
The default IRQ for LPT2 is IRQ 5.
7
IRQ 7.
Pl
IRQ 3.
0
COM1-IRQ 4, memory addresses 03F8-03FF COM2-IRQ 3, memory addresses 02F8-02FF COM3-IRQ 4, memory addresses 03E8-03EF COM4-IRQ 3, memory addresses 02E8-02EF pg. 396
IRQ Ports 2 & 9 -Taylor
An IRQ is an electrical signal generated by a device needing attention. Usually, it means that some event has occurred such as data being received and ready to use. The IRQ signal is sometimes connected directly to the processor or in some cases to a dedicated interrupt handling circuit. When the processor is told the interrupt has happened it calls the ISR to handle it. The ISR is software that deals with the needs of the device that requested it. Usually, the device is read or some system action is taken to clear the condition that caused the IRQ then the interupt system is reset to make it ready for use again. On most systems, the IRQ signal forces the processor to save it's current program counter so it knows where to return when the ISR is finished, then it jumps to a hard-wired address called the Interrupt Vector where the code for the ISR is placed. At the end of the ISR, the program counter is restored and the program carries on from where it was before the interrupt paused it. Antonio Holl
By default IRQ 7 is assigned to LPT1.
5
IRQ 3.
IRQ 0 - System timer. IRQ 1 - Keyboard. IRQ 2 - Cascaded signals from IRQs 8-15. IRQ 3 - COM2 (Default) and COM4 (User) serial ports IRQ 4 - COM1 (Default) and COM3 (User) serial ports IRQ 5 - LPT2 Parallel Port 2 or sound card IRQ 6 - Floppy disk controller IRQ 7 - LPT1 Parallel Port 1 or sound card (8-bit Sound Blaster and compatibles) IRQ 8 - Real time clock IRQ 9 - Free / Open interrupt / Available / SCSI. Any devices configured to use IRQ 2 will actually be using IRQ 9. IRQ 10 - Free IRQ 11 - Free IRQ 12 - PS/2 connector Mouse. IRQ 13 - ISA / Math Co-Processor IRQ 14 - Primary IDE. If no Primary IDE this can be changed IRQ 15 - Secondary IDE These are just a set of standard IRQs. For much more detail check our Ralf Brown's list located at http://www.cs.cmu.edu/~ralf/files.html
IRQ 1 is used exclusively for the keyboard controller.
None. Its the graphics card that uses an IRQ. The monitor is just a peripheral.
IRQ 0
0
The Linux equivalent of LPT1 is /dev/lp0.
This problem won't be found in any relatively modern computer. On a much older system, it would indicate that the sound card and LPT1 were sharing the same IRQ.
IRQ 14
IRQ 3