Re: A86: Rom Central - Database interactivity with rom calls


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Re: A86: Rom Central - Database interactivity with rom calls




'Jforcecmdnochar' is used to send the 86 back to the 'homescreen' context.
The stack is set back to the value that it was at when the system turns on.
It is a safe way to exit out of an asm program if you don't want to 
get the stack backto it's proper value before 'ret'. It doesn't copy the
program
anywhere. If you want to save high scores then write it to a var. You can 
create vars with illegal names so that they cannot be modified wothout an
asm program. Start your var name with a char < 'A'. Avoid @,#,$,!,^,? they are
used by the 86 for edit buffers.

Later
Pat 

------------------
Original text

From: Jimmy =?iso-8859-1?Q?M=E5rdell?= <yarin@acc.umu.se>, on 2/24/98 3:28 AM:

At 18:30 1997-02-22 -0700, you wrote:
>
>why should we exit with this command?

I disassembled it a bit:

409C  C36305    jp    0563

0563  ED7BD6C1  ld    SP,(C1D6)
0567  0E00      ld    C,00
0569  C5        push  BC
056A  1805      jr    07         [0571]

0571  FDCB0CB6  res   6,(IY+0C)
0575  214109    ld    HL,0941
0578  CDC405    call  05C4

 05C4  - a long routines which changes many system variables

057B  97        sub   A
057C  C1        pop   BC
057D  C3A103    jp    03A1


It changes a lot of flags in IY-land, change systemvariables,
resets the stack (thus making is possible to quit the
program anywhere, without having to bother to reset the stack) etc.
If you press ON during the program, it won't BREAK. It clears
the keyboard buffert. It saves a lot of code.

Also, it MIGHT copy the program back to the page 2-7, thus
saving hiscore and similiar. Or some other calc MUST do that.
Pat? :-)

--
Real name: Jimmy M_rdell                 
IRC......: Yarin                         
Email....: mailto:yarin@acc.umu.se      <-- NEW E-MAIL ADDRESS!!!!
Homepage.: http://www.algonet.se/~mja/


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