Donkey Kong Country play rules (Yoshifanatic's disassembly)

In the first US release, lives are set to 5 when a game is started or a saved game loaded, or to 50 when a cheat flag the code tests is set. The same routine sets the banana count and the first two animal token counts to 0, and a load copies its saved fields back afterward without the lives among them. dkc/starting-lives

About: Donkey Kong Country Lives

Value: lives 5 · cheat lives 50 · cheat bit $0004

The flag is bit $0004 of the cheat flags, which the disassembly names the 50-lives cheat; the code shows only that the bit gives 50. That the second caller loads a saved game rests on the disassembly's file-select names. The 16-bit store at line 64326 clears $0571 and $0572, the first two of the four token counts the token routine indexes (dkc/animal-tokens).

In the first US release, 100 bananas give a life (converted from hex). The banana counter on screen counts up one at a time toward the bananas collected; when it would pass 99, the game takes 100 from the bananas collected, sets the counter back to 0, and adds a life. The life waits instead when the sprite number the life routine keeps isn't positive: the number is made negative, and a later routine adds the life and sets it back to 0. In one mode, set by a flag the code tests, the counter runs to 999 and goes back to 0 with no life (both converted from hex). dkc/banana-life

About: Donkey Kong Country Extra life

Value: bananas 100

The sprite number is kept at $1E25; the mode flag is bit $0400 of the word at $1E15. A second 100 counted while a life waits takes $1E25 from $FFFF to $FFFE, still negative, and the later routine pays one life for both (read from the two routines; not measured).

In the first US release, the routine that plays the sound the disassembly names "life balloon" adds to the lives a value read from a field of the touched sprite, and adds the same value to a field of the sprite the life routine keeps, whose role isn't read. Where the value is set isn't read. dkc/life-balloon

About: Donkey Kong Country Extra life

The kept sprite's number is at $1E25 (dkc/banana-life); the value is the touched sprite's field $145D. That the routine runs when a balloon is touched rests on the sound's name; the test before it (line 53118) isn't read.

In the first US release, each of the four kinds of animal token has its own count. A token adds 1 to its kind's count, and a count of 4 becomes 1, so the fourth token of a kind counts as the first of a new set. The new count, 1 to 3, picks one of three consecutive sounds, and at 3 the game sets two values whose effect isn't read here. dkc/animal-tokens

About: Donkey Kong Country Collectibles

The disassembly names the four kinds, in order, Winky, Expresso, Rambi, and Enguarde; the routine tests the first three by animation number and takes anything else as the fourth. At 3 it sets the word at $1929 to $11 and gives the current Kong's sprite the value $51 in its field $1029.

In the first US release, the routine the disassembly labels KONG letters adds a life when four letter flags are all set: once a test it runs first passes (unread), it adds the sprite's own flag to the four, and when all four are set it resets them, sets two other flags whose effect isn't read, and adds a life. dkc/kong-letters-life

About: Donkey Kong Country Extra life

The flags are the low four bits of the word at $057F, which the disassembly names the collected KONG letters; the sprite's flag is its field $13E9. The reset writes $90 to the low byte, which clears the four and sets bits $10 and $80; bit $10 changes how a letter sprite starts (line 115349), and what either bit does after that isn't read.

In the first US release, a Rambi or Enguarde token count carries into the next game unless the console is reset (computed). Starting or loading a game sets the first two of the four animal token counts to 0 and leaves the other two as they were: by the disassembly's names, Winky's and Expresso's counts are cleared, and Rambi's and Enguarde's are not. The reset fills work RAM with zero bytes by DMA through its data port, starting at address 0. The only other writes to the four counts are the token routine's own (dkc/animal-tokens) and a copy of 280 bytes of player state that starts two bytes below the counts (280 converted from hex): at a game's start the game copies the state to both players' stores, and in two-player mode, as far as the code shows (the mode isn't read), each change of player saves the state to one store and loads it from the other. dkc/token-counts-carry

About: Donkey Kong Country Collectibles

Value: cleared Winky, Expresso · kept Rambi, Enguarde · state bytes 280

The counts are $0571 (Winky) to $0574 (Enguarde), by the disassembly's names and the token routine's index order (Winky 0, Expresso 1, Rambi 2, otherwise 3). The game-start and file-load clears are 16-bit STZ stores at $0571. The state copy runs from $056F, so it holds all four counts; the swap runs only when the word at $42 is 2, which by the game's design is two players taking turns, not read here. The fill runs two passes of 65,536 bytes; that they cover all of work RAM, rather than one address, rests on the port's address stepping after each byte, which no quoted source says. The search for other writes covered the routine file's direct, indexed and long addressing, not code that computes the address at run time.