[comp.os.msdos.apps] msdos tsr hardware interrupt problem

mmz@unhd.unh.edu (Mike M Zhu) (05/03/91)

Hi, I have a problem in using (MS_DOS 3.1) INT_28h. I am using a IRQ10.asm 
as hardware interrupt service routine to set an internal flag (DUMPFLAG) then 
back to DOS. DOS will automaticly call INT_28h during waiting keyboard input. 
In my new INT_28h IRS, it check DUMPFLAG first. If it is true calling dump 
subroutine to dump 64k data into the harddisk via using INT_26h, otherwise 
doing idle interrupt (IRET), then switch control back to DOS. Now dumpping 
data is fine, and looks the control is in the DOS from indication on the 
screen after a hardware interrupt signal triggered.

But then if you type any new word in keyboard, PC will luck up except type
in Ctrl_C (or Ctrl_Break). A lot of books say this way should work well by 
using new INT_28h TSR which can safely use DOS functions. If you are familiar
that kind of application, please tell me your opinion via E_MAIL. 

Please em: mmz@unhd.unh.edu or M_ZHU@UNHH.EDU

Thanks

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Sender: mike zhu
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Organization: University of New Hampshire
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