# Glitch City Laboratories Archives

Glitch City Laboratories closed on 1 September 2020 (announcement). This is an archived copy of a thread from Glitch City Laboratories Forums.

You can join Glitch City Research Institute to ask questions or discuss current developments.

You may also download the archive of this forum in .tar.gz, .sql.gz, or .sqlite.gz formats.

## Arbitrary Code Execution Discussion

### Any way to change bike speed using 8F? - Page 1

Previous Page

- 1

Next Page

#### Any way to change bike speed using 8F?

Posted by: naf102
Date: 2016-07-23 19:43:21
Is there any way to change the Bicycle's speed to light speed? I know the event flag for bike speed is D700 (using the RAM map). My question is how would I alter this using 8F to edit the address?

#### Re: Any way to change bike speed using 8F?

Posted by: Flandre Scarlet
Date: 2016-07-23 22:00:46
D700 is actually the flag for what type of transportation you are on. 2 is surfing, 1 is biking, anything else is walking. Using 8F can make it act like a bike this waybut without the music. Also using it inside still won't let you bike inside.

#### Re: Any way to change bike speed using 8F?

Posted by: TheUnReturned
Date: 2016-07-24 04:35:20
In other word, you cannot change the speed.
Why don't you just speed up the game itself?

#### Re: Any way to change bike speed using 8F?

Posted by: Krys3000
Date: 2016-07-24 10:11:02
It's a misindication on DataCrystal, which is not very clear.
If you put 01 in $D700, you will get on the bike - but in fact you'll see the player walking at the speed of the bike, hence the name in DataCrystal, as long as you don't refresh the screen (open/closing a menu).

#### Re: Any way to change bike speed using 8F?

Posted by: Max
Date: 2016-09-16 17:39:32
Looking at project pokered's overworld.asm, riding the bike is twice as fast as walking because:

[li]if you are on a bike (overworld.asm::OverworldLoopLessDelay.moveAhead2 line 276), and not jumping a ledge, it calls overworld.asm::DoBikeSpeedup (line 377)

[li]Here this subroutine returns immediately if an NPC map script (eg trainer walking towards you) is active[/li]
[li]If you aren't on cycling road OR if you aren't pressing UP, LEFT, or RIGHT: you DoBikeSpeedup.goFaster (line 387) which just calls overworld.asm::AdvancePlayerSprite[/li]

[/li]
[li]regardless of bike status OverworldLoopLessDelay.moveAhead2 goes straight to OverworldLoopLessDelay.normalPlayerSpriteAdvancement, which calls overworld.asm::AdvancePlayerSprite (line 287)[/li]

(AdvancePlayerSprite does the actual movement)
As you can see it is possible to call AdvancePlayerSprite twice, resulting in x2 speed. Unfortunately the above subroutines are in ROM, so modification is generally out of scope for ACE.

> Also using it inside still won't let you bike inside.

Perhaps using the bike item indoors is disabled, but in the overworld (which includes indoors I assume) I saw no checks in the movement code. Perhaps you could try jumping straight to a "mount bike" subroutine with ACE.

#### Re: Any way to change bike speed using 8F?

Posted by: ISSOtm
Date: 2016-09-16 18:21:35
I guess the only way would be to edit the map script to move you.
Previous Page

- 1

Next Page