Page Byte Address Length Description
127 0 32512 1
x-coordinate of the leftmost column of the skool on screen
Modified by the routines at 24576 and 24731.
127 1 32513 8
UDG back buffer
Used by the routine at 24843.
127 9 32521 1
Number of on-screen character squares that need refreshing (unused)
Used by the (unused) routine at 25830.
127 10 32522 2
Unused
127 12 32524 84
Screen refresh buffer (SRB)
Used by the routines at 27008, 27026, 28807, 29394 and 29735. Each byte of the SRB corresponds to a segment of 8 character squares on the screen, the leftmost of which will be at x=0, x=8, x=16 or x=24. Each bit set in an SRB byte corresponds to a character square in the segment that needs refreshing. Bit 0 corresponds to the leftmost character square in the segment, bit 7 to the rightmost character square.
127 96 32608 4
Unused
127 100 32612 2
Speech bubble lip coordinates
Used by the routines at 29518 and 29746.
127 102 32614 34
UDG references and attribute bytes of the part of the skool overwritten by the speech bubble and lip
Used by the routines at 29518 and 29746.
127 136 32648 4
Unused
127 140 32652 8
Workspace used to find the main kid closest to a teacher
Used by the routine at 30890.
127 148 32660 2
Unused
127 150 32662 2
Safe combination letter message
Used by the routine at 63829.
127 152 32664 2
Unused
127 154 32666 1
Identifier for CREAK's birth year battle
Used by the routines at 63573 and 63779.
127 155 32667 4
CREAK's year of birth
Used by the routines at 63191 and 63573. Holds a copy of the battle-year message corresponding to CREAK's birth.
127 159 32671 4
Safe combination code
Used by the routines at 63270 and 63573. Holds the ASCII codes of the letters in the safe combination (in the right order). The teachers' safe combination letters are stored at 32675.
127 163 32675 4
Teachers' safe combination letters
Used by the routines at 63573 and 63829. Holds the ASCII codes of the teachers' safe combination letters. The safe combination itself is stored at 32671.
127 167 32679 1
Unused
127 168 32680 5
Reading Room blackboard contents buffer
Used by the routine at 63270.
127 173 32685 1
Unused
127 174 32686 5
White Room blackboard contents buffer
Used by the routine at 63270.
127 179 32691 1
Unused
127 180 32692 5
Exam Room blackboard contents buffer
Used by the routine at 63270.
127 185 32697 8
Unused
127 193 32705 1
ERIC's stand-up delay counter
Used by the routine at 62938 while in demo mode.
127 194 32706 2
Hi-score
Used by the routines at 27406 and 32470.
127 196 32708 2
Score
Used by the routine at 27387.
127 198 32710 2
Lines total
Used by the routines at 30464 and 63931.
127 200 32712 1
Lesson status flags
Various status flags for the current lesson.
Bit(s) Meaning
0 End of lesson/playtime (always reset)
1-3 Unused
4 Next lines reprimand for the teacher fetching the truant ERIC (toggled by 30636)
5 Set after a teacher has found the truant ERIC (see 30636)
6 Set after a classroom lesson has started with ERIC present (see 62208) (checked by 30636; reset by 26342)
7 Set after EINSTEIN has had a chance to grass on the absent ERIC (see 62208), or after dinner has started (see 31854) (checked by 30636; reset by 26342)
127 201 32713 1
Lesson signal flags
Bits 0-3 are used by the classroom-based command lists to indicate that or check whether a teacher has arrived at the classroom door to start the lesson.
Bit(s) Meaning if set
0 Teacher has arrived at the Map Room
1 Teacher has arrived at the Reading Room
2 Teacher has arrived at the Exam Room
3 Teacher has arrived at the White Room
4-6 Unused
7 EINSTEIN is speaking (set by 31919; checked by 31162 and 31944; reset by 31178)
127 202 32714 1
Stampede signal flags
These flags are set and reset by command list 204, and checked by command list 206.
Bit(s) Meaning if set
0 Little boy no. 1 is ready to stampede
1 Little boy no. 1 is ready to stampede again
2-7 Unused
127 203 32715 1
Special playtime signal flags
These flags are used during the special playtimes (when EINSTEIN is going to tell MR WACKER what ERIC's up to, BOY WANDER has hidden a pea-shooter on the fire escape, or ANGELFACE has mumps).
Bit(s) Meaning if set
0 Little boy no. 10 is waiting for ERIC to respond to the message just delivered (set and reset by 63488; checked by 63352)
1 Unused
2 EINSTEIN is ready (set by command list 212; checked by command list 208)
BOY WANDER is ready (set and reset by command list 216; checked by command lists 208 and 218)
3 MR WACKER is ready (set by command lists 214 and 218; checked by command list 208)
4 Little boy no. 10 has told ERIC about EINSTEIN (set by command list 208; checked by command list 212)
Little boy no. 10 has told ERIC about BOY WANDER (set by command list 208; checked by command list 216)
Little boy no. 10 has told ERIC about ANGELFACE (set by command list 210; checked by command list 220)
5 EINSTEIN has grassed on ERIC (set by command list 212; checked by command list 214)
ERIC has mumps (set by 64042; checked by command list 222)
6-7 Unused
127 204 32716 14
Unused
127 218 32730 1
Birth year question indicator
Used by the routine at 63779, and reset at the start of each lesson by the routine at 26342. Holds 0 if MR CREAK has not yet asked the birth year question during the current lesson, or 1 otherwise.
127 219 32731 13
Unused
127 232 32744 1
ERIC's main action timer
Decremented by the main loop at 26471; when it becomes zero, the keyboard is checked and ERIC is moved accordingly (see also 25856, 25916, 25962 and 26880).
127 233 32745 1
ERIC's midstride/mid-action timer
Zero unless ERIC is midstride or has his arm raised while writing on a board (see 25916); if non-zero, the value is copied to the main action timer at 32744 after ERIC has lowered his arm or moved from the midstride position (see 25856).
127 234 32746 1
Game mode indicator
Used by the routine at 28143.
Value Meaning
0 Demo mode
1 Shields need to be flashed
2 All shields flashing; ERIC needs to find the safe combination
3 Shields need to be unflashed
127 235 32747 1
Shield counter
Used by the routine at 28143.
127 236 32748 1
Next clean pixel column on the Reading Room blackboard
Used by the routines at 28994, 29160 and 63270.
127 237 32749 1
Number of the character who last wrote on the Reading Room blackboard
Used by the routines at 29160, 29284, 63056 and 64016. Holds 0 if the board is clean.
127 238 32750 1
Next clean pixel column on the White Room blackboard
Used by the routines at 28994, 29160 and 63270.
127 239 32751 1
Number of the character who last wrote on the White Room blackboard
Used by the routines at 29160, 29284, 63056 and 64016. Holds 0 if the board is clean.
127 240 32752 1
Next clean pixel column on the Exam Room blackboard
Used by the routines at 28994, 29160 and 63270.
127 241 32753 1
Number of the character who last wrote on the Exam Room blackboard
Used by the routines at 29160, 29284 and 63056. Holds 0 if the board is clean.
127 242 32754 1
Lines-giving delay counter
Used by the routine at 30636.
127 243 32755 1
Character number of the teacher who last gave ERIC lines
Used by the routine at 30636.
127 244 32756 1
Lesson descriptor
Used by the routines at 26342, 30636, 31040, 31188 and 32178. The room ID is stored in bits 0-3, and the teacher ID in bits 4-7. See the list of lesson descriptors at 44256.
127 245 32757 1
ERIC's knockout delay counter
Used by the routine at 27303.
127 246 32758 1
Action timer for ERIC
Used by the routines at 62495, 62628 and 62771 to coordinate ERIC's movements while firing his catapult, hitting, or jumping.
127 247 32759 2
Lesson clock
Decremented in the main loop at 26471. When it reaches 0, it is reset to 5376 by the routine at 26342. It is also checked by the routines at 30636 and 31807, and modified by the routines at 26880, 63456, 63488, 63668, 63931 and 64004.
127 249 32761 1
Current lesson number
Used by the routines at 26342 and 31815. Holds the index (0-63) into the main timetable. It is adjusted by the routine at 26880 before starting a new game.
127 250 32762 1
Last value seen in the system variable FRAMES
Stores the value of the LSB of the system variable FRAMES as it stood at the end of the last pass through the main loop (see 26471).
127 251 32763 1
ERIC's status flags
If ERIC is doing anything other than walking or standing still, one of the bits here will be set.
Bit Meaning if set Handler Checked by
0 ERIC is firing the catapult 62495 27353
1 ERIC is hitting 62628 27353
2 ERIC is jumping 62771 27353, 30636, 30890, 31229
3 ERIC is being spoken to by little boy no. 10 63352 27353
4 ERIC has just been knocked down or unseated 27303 27353
5 ERIC is writing on a blackboard 63146 26471
6 Unused (always reset) 25983, 26084, 26194
7 ERIC is sitting or lying down (set by 27303 or 27823) 25956, 62574, 62938, 63056
127 252 32764 1
Last key pressed
Holds the ASCII code of the last key pressed. Set by the routines at 26471 and 63056; checked by the routines at 25916 and 26194.
127 253 32765 1
Number of the character just moved (152-171)
Used by the routine at 25126.
127 254 32766 2
Random number seed
Used by the routine at 24993.