Routines
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$3B5E: Move the current character
Used by the routine at $3AB4.
$3B5E LDA $60 Pick up the current character number from $60.
$3B60 CMP #$12 Is it $12 (BOY WONDER's pellet)?
$3B62 BEQ $3BA0 Branch if so.
$3B64 CMP #$13 Is the current character number $13 (ERIC's pellet)?
$3B66 BEQ $3BA0 Branch if so.
$3B68 DEC $FF Decrement the character's movement speed change delay counter at $FF.
$3B6A BEQ $3B7A Branch if it's time to consider a change in movement speed.
$3B6C LDA $FF Pick up the character's movement speed change delay counter from $FF.
$3B6E LSR A Is the new value even?
$3B6F BCC $3BA0 Branch if so (half the time) to move the character.
$3B71 LDA $3F Pick up the flags byte from $3F.
$3B73 AND #$40 Is bit 6 set, meaning the character is running (or otherwise moving quickly)?
$3B75 BNE $3BA0 Branch if so to move the character now.
$3B77 JMP $3BE6 Otherwise return without having moved the character.
It's time to consider a movement speed change for this character.
$3B7A LDA $D41B Generate a random value between 4 and 67.
$3B7D AND #$3F
$3B7F ADC #$04
$3B81 LSR A Now 2<=A<=33, and the carry flag is set if the random value is odd.
$3B82 STA $FF Reinitialise the movement speed change delay counter at $FF with this value.
$3B84 BCC $3B90 Branch if the random value is even.
$3B86 LDA $3F Set bit 6 of the flags byte at $3F: the character is running (or otherwise moving quickly).
$3B88 ORA #$40
$3B8A STA $3F
$3B8C AND #$05 Is bit 2 of the flags byte set, meaning this character is either a teacher, or EINSTEIN speaking?
$3B8E BEQ $3BA0 Branch if not to move the character now.
$3B90 LDA $3F Reset bit 6 of the flags byte at $3F: the character is walking (or otherwise moving) at a normal pace.
$3B92 AND #$BF
$3B94 STA $3F
$3B96 AND #$0A Is bit 1 or bit 3 of the flags byte set (meaning the character is a stampeding boy, MR WACKER looking for the pea-shooter, or EINSTEIN waiting to answer a teacher's question)?
$3B98 BEQ $3BA0 Branch if not to move the character now.
$3B9A LDA $3F Set bit 6 of the flags byte at $3F: the character is running (or otherwise moving quickly).
$3B9C ORA #$40
$3B9E STA $3F
Now we consider the character's next move. From this point, the following steps are taken:
  • If there is an uninterruptible subcommand routine address at $B0, jump to it.
  • Otherwise, if there is a continual subcommand routine address at $39, jump to it (and then return to execute the next step below).
  • If there is an interruptible subcommand routine address at $AA, jump to it.
  • Otherwise, restart the command list if bit 7 of the flags byte at $3F is set.
  • If there is a primary command routine address at $29, jump to it.
  • Otherwise, collect the next primary command routine address from the command list, place it at $29, and jump to it.
The address of one of the following uninterruptible subcommand routines may be present at $B0:
Address Description
$0FBA Control the horizontal flight of a catapult pellet
$1042 Control the vertical flight of a catapult pellet
$1CB4 Deal with a character who's been dethroned (1)
$1CCB Deal with a character who's been dethroned (2)
$1CEC Deal with a character who is looking for a seat
$267A Make ANGELFACE throw a punch (1)
$2696 Make ANGELFACE throw a punch (2)
$26E0 Make ANGELFACE finish punching or BOY WONDER finish firing his catapult
$2A43 Deal with a character who has been knocked over
$2B21 Make BOY WONDER fire his catapult (1)
$2B3F Make BOY WONDER fire his catapult (2)
$2B52 Make BOY WONDER fire his catapult (3)
$2B9F Make BOY WONDER fire his catapult (4)
The address of one of the following continual subcommand routines may be present at $39:
Address Description
$26EF Check whether ANGELFACE is touching ERIC
$270D Make ANGELFACE hit now and then
$2797 Make the stampede leader trip people up on the way to a random location
$2873 Make a little boy trip people up
$2CA5 Make BOY WONDER fire his catapult now and then
The address of one of the following interruptible subcommand routines (or an entry point thereof) may be present at $AA:
Address Description
$0C3F Make a character track down ERIC
$1129 Make a character write on a blackboard
$136F Guide a character to an intermediate destination
$13F3 Guide a character up or down a staircase
$16E9 Make a teacher wipe a blackboard
$1F1E Make a teacher wait for EINSTEIN to finish speaking
$2387 Make a character speak
The address of one of the following primary command routines (or an entry point thereof) may be present at $29:
Address Description
$09E9 Make a teacher conduct a class
$0A57 Do nothing
$0A58 Make a teacher conduct a class with ERIC
$0E35 Make a teacher perform dinner duty
$0EB4 Restart the command list
$0EC2 Restart the command list unless it's time to start the lesson
$105B Make a character go to a random location
$1A04 Make a character walk up and down until a certain time
$1D16 Make a character find a seat
$1F4D Control EINSTEIN during class
$1FA0 Make a teacher tell the kids to sit down
$2757 Make a teacher tell ERIC to go home, and end the game
$277D Make MR WACKER give ERIC 2000 lines
$27AB Make a character walk up and down a few times or until a certain time
$284F Make MR WACKER run to a given location
$2865 Place a continual subcommand routine address into a character's buffer
$2885 Make a little boy find and follow little boy no. 1
$28AB Make BOY WONDER write on a blackboard
$28BC Make little boy no. 10 give ERIC a message
$2A99 Make a character find ERIC
$2AF9 Raise the signal for a certain event and move to the next command
$2B0D Lower the signal for a certain event and move to the next command
$3BA0 LDA $B1 Is there an uninterruptible subcommand routine address at $B0?
$3BA2 BEQ $3BA7 Branch if not.
$3BA4 JMP ($00B0) Otherwise jump to the uninterruptible subcommand routine.
$3BA7 LDA $3A Is there a continual subcommand routine address at $39?
$3BA9 BEQ $3BB4 Branch if not.
$3BAB LDA #$3B Push $3BB3 onto the stack so that we return to $3BB4 below after executing the continual subcommand routine.
$3BAD PHA
$3BAE LDA #$B3
$3BB0 PHA
$3BB1 JMP ($0039) Jump to the continual subcommand routine.
$3BB4 LDA $AB Is there an interruptible subcommand routine address at $AA?
$3BB6 BEQ $3BBB Branch if not.
$3BB8 JMP ($00AA) Otherwise jump to the interruptible subcommand routine.
$3BBB LDA $3F Pick up the flags byte from $3F.
$3BBD ASL A Is a command list restart required (bit 7 set)?
$3BBE BCC $3BDF Branch if not.
$3BC0 LDA $3F Reset bit 7 of the flags byte at $3F.
$3BC2 AND #$7F
$3BC4 STA $3F
$3BC6 LDA $3D Copy the command list start address from $3D to $3B. This has the effect of restarting the command list.
$3BC8 STA $3B
$3BCA LDA $3E
$3BCC STA $3C
$3BCE LDY #$00 Remove the address of any continual subcommand routine from $39.
$3BD0 STY $3A
This entry point is used by the routine at $2865.
$3BD2 JSR $3BE7 Collect the address of the primary command routine from the command list and place it into the character's buffer at $29.
$3BD5 STA $29
$3BD7 JSR $3BE7
$3BDA STA $2A
$3BDC JMP $3BE3 Jump forward.
$3BDF LDA $2A Is there a primary command routine address at $29?
$3BE1 BEQ $3BCE Branch back if not to collect one from the command list.
$3BE3 JMP ($0029) Jump to the primary command routine.
$3BE6 RTS
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