Re: Software for MS-DOS 1.25

From: Michał Pleban <*lists_at_michau.name*> Date: Fri, 20 Oct 2017 12:53:29 +0200 Message-ID: <59E9D5A9.1020205@michau.name> · lists_at_michau.name

smf wrote:

> Sorry, I meant "Keyboard Intercept (INT 15h, Function AH =4Fh)"
> 
> As each key is pressed the INT 09h handler calls INT 15H with AH=4FH.
> You could then just set a bool and check that in your main loop.
> 
> That would be more useful if you wanted to wait for any key as you can
> also trap keys that don't make it into the keyboard buffer as a key press.
> 
> Looking at the bios keyboard key head/tail pointers was common though,
> it would be worth making sure that was compatible anyway. Some software
> even changes them and pokes keys into the buffer, to simulate key presses.

This all might be tricky because there is no INT 9 here telling us that
a key on the keyboard was pressed. We can only poll the keyboard with
the IPC 10h and 11h functions.

Maybe it could be polled from the TOD clock interrupt?

Regards,
Michau.

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