SpartaDos programming question

[ebiguy]

Hi everybody,

 

I tried to use symbol U_LOAD of SpartaDos 4.46 to run another program but I don't understand how to deal with FLAG symbol.

I don't see the solution in the documentation (translated by Google).

Basically, I am doing something like this:

 

ldy #0
lda #<executable_filename
sta FILE_P,y
iny
lda #>executable_filename
sta FILE_P,y
sty FLAG
jsr U_LOAD

 

It does not run anything.
Of course, all uppercase labels (FILE_P, FLAG and U_LOAD are binded at runtime). I can see the value in Altirra ($0CE3 for FILE_P,...)

The filename is also correct. When I place in executable_filename a wrong filename I got an error. With a right filename, the call to U_LOAD returns but nothing is run.

Maybe the problem is with FLAG symbol ?

I am not sure about 1) the way to fill it and 2) the value to set to run the executable.

I don't know if I should store something in FLAG or consider FLAG as a pointer and if I can/must change FLAG to point to a byte inside my program ?

And which value to use (the doc says bit 7 should be cleared but what is the use of the other bits, if any) ?

 

Thank you for your help.

 

[drac030]

FLAG must be zeroed here, this selects the proper function of U_LOAD (i.e. load & execute).

 

EDIT: also note that constructs like "lda #<some_address" are forbidden in a relocatable binary file. Example:

 

ldx #$02

fn lda namep-1,x

sta FILE_P-1,x

dex

bne fn

stx FLAG

jsr U_LOAD

...

namep .word name

name .byte 'FOOBAR.COM',$9b

Edited December 29, 2013 by drac030

[ebiguy]

Hi drac030, I put zero (was 1 with my previous code) and now it works !

I should have try it before posting...sorry.

Thank you for your lightning fast answer !!!

 

BTW, porgramming for SpartaDOs is a real pleasure.

Using SpartaDos is just a new experience on the Atari.

Many thanks to all SpartaDos contributors and keep up the good work.

Bye.