Altirra Debug Problem

[TGB1718]

I set debug mode in Altirra, I load my program into memory, Open the Source Files, press F8 so that

I can use the command line, set the program counter to the start of my program, open a memory window to

watch data I'm interested in.

Then using the 't' command (one step) I start stepping through the program (just press <return> after the first 't',

but this happens every time after a load.:-

Altirra> r pc 2000
Altirra> t
(337783:248,  3) A=00 X=FF Y=00 S=EF P=33 (    ZC)  2002: 8D F5 21          STA $21F5    [$21F5]
Altirra> 
(337783:248,  7) A=00 X=FF Y=00 S=EF P=33 (    ZC)  2005: 8D F6 21          STA $21F6    [$21F6]
Altirra> 
(337783:248, 11) A=00 X=FF Y=00 S=EF P=33 (    ZC)  2008: A9 00             LDA #$00
Altirra> 
(337783:248, 18) A=00 X=FF Y=00 S=EC P=37 (   IZC)  C018: 2C 0F D4          BIT NMIST    [$D40F] = $5F
 

It jumps from my program to C018, if I reset the program counter back to (in this case 2008) I can continue to use

the 't' command and them press return and it works forever.

 

I know the step is F11, but just pressing return should still work ?

 

Or am I just doing it wrong ?

 

[mellis]

Sure seems like you are observing an interrupt firing, and as a result, you are being carried into the OS.