[hatari-devel] b help question (HBL $0)

[Eero Tamminen]

Hi,

On keskiviikko 01 kesäkuu 2011, Laurent Sallafranque wrote:
> When I enter b help in the debug console, I get all the help for
> breakpoint.
> 
> I can read the following :
> 
> ...
>   Valid Hatari variable names (and their current values) are:
>    - AesOpcode ($ffff), by default FFFF
>    - BiosOpcode ($ffff), by default FFFF
>    - FrameCycles ($44)
>    - GemdosOpcode ($ffff), by default FFFF
>    - HBL ($0)
>    - LineAOpcode ($ffff), by default FFFF
>    - LineCycles ($44), is always divisable by 4
> ...
> 
> 
> Is it really $0 for HBL ?
> I think not.

It's the value of the Hatari internal "nHBL" variable.

If you've entered the debugger by pressing Altgr+Pause shortcut key,
that's processed only in Video_InterruptHandler_VBL():
---
        /* Start VBL, HBL and Timer B interrupts (this must be done after 
resetting
         * video cycle counter setting default freq values in 
Video_ClearOnVBL) */
        Video_StartInterrupts(PendingCyclesOver);

        /* Act on shortcut keys */
        ShortCut_ActKey();
---

If you check HBL at some other point, e.g. after entering debugger due
to some breakpoint, HBL has different values.


	- Eero