The game
Raiders of the Lost Ark is a game released in 1982 for the Atari 2600 based on the movie with the same name. The objective in this game is for Indy to find the ark of the lost covenant. Interestingly this is the first ever movie liscensed video game.
Technical details
Ark manipulation
There are 16 possible locations for the ark, as determined by address 0x000C, and each frame during opening screen increments the location. I manipulated the ark into the closest possible location, which is one mesa from the one you teleport to (note: you can't manipulate the ark to appear on the mesa you teleport to, that requires a mesa location of 0, which can't be manipulated).
Black Market
When going to the black market, I need 3 gold. 1 to bribe the guy, (Yes that weird blob is a person) and 2 to buy a shovel (shovel's are expensive!)
Frame rules, timer, and the long wait
This game has a global clock, by which many things depend. For instance, to see the map, you have to wait for the "sun" to light up the map room. This can take several minutes. In fact, this is about 50% of the time of the best unassisted runs (which run about 7 minutes). Since I have the power of tool-assistance, I don't need a map, I know where the ark is, so I can avoid this 3+ minute frame rule, whew!
However, the treasure room operates on a lengthy frame rule as well. I did the best planning I could to minimize the frame rules, but it is unavoidable due to getting
the Chai (which looks like a uh...sailboat?). This item I can trade to a merchant at the market to get access to the black market. Even with a 25 second wait this is a big shortcut. The alternative is to use the ankh to teleport to the mesas, then go all the way down (which is time consuming), into the map room, through the thieves cave. This also costs you the ankh, so you can't teleport into the mesa room from there, so you have to go back to the market, then go all the way back down using the hourglass. This process is about 25 seconds longer overall. The down side is a rather lengthy amount of time just waiting.
Treasure room logic - if you grab just gold, you leave and go back to the jail room outside of a jail cell, however, if you grab a treasure item it sends you back to the jail cell, where you must have a gun or a whip in order to get out. This necessitates why I have to get one more gold after the long wait. Even though I have plenty of time to get it during the wait, I must drop the whip in order to have everything i need to complete the game from then on (your max carrying capacity is 6 items). And I can't drop the whip before getting a treasure else I'm stuck in jail. (There is a way out of jail but it involves falling into the marshes and dying, which is way slower than just picking up one more gold before I leave).
Note at the end, I only have the required shovel to dig for the ark. Awesome item planning don't you think?
The Mesa
To go from mesa to mesa, I have to use the grappling hook. By grappling hook I mean the hourglass icon clearly. And by grappling, I mean a dot that moves around the screen in a diamond pattern, clearly. This was some fun logic to TAS, getting it to widen in such a way to get to the next mesa quickly using the most counter-intuitive "grappling" logic I've ever seen.
Ram Addresses
- 0001 Screen Num
- 0002 Frame Counter
- 0003 Seconds (64 frames
- 000A B Button presses
- 000C Ark Location
- 0012 Last Pressed, Controller 2
- 0044 Num Items
- 0049 Player X
- 0052 Snake Y pos
- 0037 Inventory Slot 1
- 0038 Inv Slot 1 - Secondary sprite
- 0039 Inventory Slot 2
- 003A Inv 2 Secondary Sprite
- 003B Inventory Slot 3
- 003C Inv 3 Secondary Sprite
- 003D Inventory Slot 4
- 003E Inv 4 Secondary Sprite
- 003F Iventory Slot 5
- 0040 Inv 5 Secondary Sprite
- 0041 Inventory Slot 6
- 0042 Inv 6 Secondary Sprite
- 004F Player Y
turska: Accepting for publication in the Vault.
