Routine Thread Index

[Deep Toaster]

Awesome! This is really convenient. Thanks!

[nemo]

i have a question about Sir's program writeback routine. what exactly does that do? does it take a program in the vat, allow you to edit it, and then you can re-save it into the vat?

[Deep Toaster]

Well, sort of. When programs are run with Asm( (or with a shell that copies the program instead of moving it to $9D95 to run), the original program's still somewhere else in RAM. So changes to, say, GDB0 wouldn't appear the next time you run the program. SIr's routine basically finds the original program in RAM, and you can edit it directly from there. No messing with the VAT is needed since all the VAT does is point to the program anyway.

[ztrumpet]

i have a question about Sir's program writeback routine. what exactly does that do? does it take a program in the vat, allow you to edit it, and then you can re-save it into the vat?

Unfortunately, Deep Thought's not entirely correct.
Program write-back is used for Self Modifying Code (often used for Saving Highscores without an external AppVar).
Basically, Program Write-back allows you to make changes to the program from where it is copied and Sir's code will copy the resulting changes back in the program file.
for example:
.TEST
_delta_list(0^r)->Str0
Disp {Str0}^r+1->{Str0}^r>Dec
This will display 1 every time unless Sir's program write-back is enabled.  I believe shells write-back automatically too, but that may be only if the program's archived.  I know in Mirage you can turn Write-back in Archive on and off.

Here's a helpful tutorial on the subject: http://future_history.freehostia.com/Files/Resources/ASM/ASMin28Days/lesson/day20.html

[Deep Toaster]

i have a question about Sir's program writeback routine. what exactly does that do? does it take a program in the vat, allow you to edit it, and then you can re-save it into the vat?

Unfortunately, Deep Thought's not entirely correct.
Program write-back is used for Self Modifying Code (often used for Saving Highscores without an external AppVar).
Basically, Program Write-back allows you to make changes to the program from where it is copied and Sir's code will copy the resulting changes back in the program file.
for example:
.TEST
_delta_list(0^r)->Str0
Disp {Str0}^r+1->{Str0}^r>Dec
This will display 1 every time unless Sir's program write-back is enabled.  I believe shells write-back automatically too, but that may be only if the program's archived.  I know in Mirage you can turn Write-back in Archive on and off.

Actually, even if it's run from RAM, most shells move the program straight to $9D95 (instead of copying) so that no matter what, it writes back since the program has to be moved back eventually. For running from archive, writeback has to copy it back and forth (and that's why the choice is there).

Btw, how was I wrong (just wondering, don't want to give false info...)?

[ztrumpet]

Btw, how was I wrong (just wondering, don't want to give false info...)?

I was wrong, as I didn't realize this:

Actually, even if it's run from RAM, most shells move the program straight to $9D95 (instead of copying) so that no matter what, it writes back since the program has to be moved back eventually. For running from archive, writeback has to copy it back and forth (and that's why the choice is there).

Sorry. 
* ZTrumpet feeds himself to the lobster


Thanks for the info!  I didn't realize they did that.

[Deep Toaster]

Btw, how was I wrong (just wondering, don't want to give false info...)?

I was wrong, as I didn't realize this:

Actually, even if it's run from RAM, most shells move the program straight to $9D95 (instead of copying) so that no matter what, it writes back since the program has to be moved back eventually. For running from archive, writeback has to copy it back and forth (and that's why the choice is there).

Sorry. 
* ZTrumpet feeds himself to the lobster


Thanks for the info!  I didn't realize they did that.

No problem, I just learned that a few days ago too

[SirCmpwn]

Wow, very useful topic!  Memo, the current version of Axe can modify programs.

[DJ Omnimaga]

Are you talking about SMC?

[LordConiupiter]

very usefull topic indeed! thanks for doing this!

[Runer112]

By the way ztrumpet, you still have yet to mark off fixed point multiplication and sprite rotating/flipping as being covered by Axe. I made a post a short while ago saying that they were outdated, but it looks like you must have missed that post. Don't miss this one!

[ztrumpet]

Whoops, sorry.  Thanks Runer.

[SirCmpwn]

While reading through this, I realized that I did some pretty badass routines I got writeback working, and appvar storage way before Axe got it, and I got MirageOS support before Axe officially got it, and I still have the only way of using a custom icon for MOS.  I actually have a few gems sitting on my calculator next time I can get them off

[DJ Omnimaga]

Yeah those were really great! I wonder if yoU'll have some more cool routines.

Also if I am ever less busy, I think one day I'll look through old Axe progress posts. It will be fun to see how things evolved since then.

[ztrumpet]

I just wanted to bump this and mention that I'm still updating it, as some of the newer members may not have seen it.