Category : Forth Source Code
Archive   : HLINTR.ZIP
Filename : HLINT.HLP

 
Output of file : HLINT.HLP contained in archive : HLINTR.ZIP
Help for interrupt processing words contained in the source file HLINT.SEQ
Tim Hendtlass July 1990.

ISR: marks the start of an Interrupt Service Routine.
- - -
ISR; marks the end of an Interrupt Service Routine.
The structure of an ISR is similar to that of a colon definition:-
ISR: list-of-things-to-do ISR;
ISR: takes care of moving to a new pair of stacks, saving the machine
state, reloading a `new copy' of F-PC and then processing the list
that makes up the ISR.
ISR; restores the saved machine state, re-enables interrupts and
resets the interrupt controller by writing 20 hex to port 20 hex.

INSTALL-INTERRUPT
given the interrupt number and the address of the routine to service
this interrupt (the interrupt vector), INSTALL-INTERRUPT places the
interrupt vector in the interrupt vector table at the correct place.

REMOVE-INTERRUPT
given an interrupt number REMOVE-INTERRUPT replaces the interrupt
vector with a vector pointing to a safe `do nothing but return' ISR
in the BIOS.

?INTERRUPT
given an interrupt number, this returns the full (segment:offset)
interrupt vector that is currently installed there.

RE-INSTALL-INTERRUPT
given a full (segment:offset) interrupt vector and an interrupt
number , RE-INSTALL-INTERRUPT replaces the existing vector with the
one it has just been given.

INT-ON
is a high level version of the machine code enable interrupt.
Although this enables the processor to process maskable interrupts,
the interrupt controller (another chip external to the processor) must
also be enabled as must the IRQ line in question if hardware
interrupts are to be processed.

INT-OFF
disables maskable interrupts at the processor. See INT-ON above.



  3 Responses to “Category : Forth Source Code
Archive   : HLINTR.ZIP
Filename : HLINT.HLP

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/