In demo mode, ERIC bases his every move on where little boy no. 11 is and what
he's doing (see the routine at F5DA). This important role means that little
boy no. 11 is in all of ERIC's classes (if he weren't, ERIC would be guilty of
truancy in demo mode). In fact, little boy no. 11 is the only character besides
EINSTEIN who joins ERIC for every class.
One consequence of this devotion to little boy no. 11 is that ERIC can
sometimes be seen going from one end of a staircase to the other three times in
succession, as if unsure of where to go. This happens because when little boy
no. 11 starts climbing a staircase, ERIC will run to the top and get there
before him, then run down to the bottom looking for him, and finally run to the
top again to catch up with him.
The version of Skool Daze that was released by Alternative Software Ltd in 1987
contains three visible differences from the version released by Microsphere in
(1) MR WITHIT's blackboard message at E800 reads 'WHY IT RAINS IN
MANCHESTER' (which doesn't fit on the blackboard) instead of 'MANCHESTER
(2) The font graphic for the '/' (slash) character is slightly broken:
(3) In the stampede playtimes (lessons 0xFC and 0xFD), the stampede
leader (little boy no. 1) walks up and down only 7 times instead of 40 while
waiting for his comrades to join him.
Note that (1) and (2) appear to be regressions, which suggests that the version
released by Alternative is based on an earlier cut of the code than the version
released by Microsphere.
The '\' (backslash) character in the Skool Daze font has a bit missing:
Interestingly, the corresponding bit is also missing from the '/' (slash)
character in the version of Skool Daze that was released by Alternative
Software in 1987 (see Alternative differences), but it is present in the
original 1984 release by Microsphere.
One pace or three?
If a teacher is conducting a class without ERIC, or is conducting ERIC's class
but has chosen not to engage in a question-and-answer session with EINSTEIN, he
will pace up and down in front of the blackboard (or map). But the number of
paces up and then down depends on the room he's in.
If he's in the White Room, he will take one pace up and then down, oscillating
between x-coordinates 29 and 30. If he's in the Reading Room, he will also take
one pace up and then down, oscillating between x-coordinates 45 and 46. And if
he's in the Map Room, he will once again take one pace up and then down,
oscillating between x-coordinates 61 and 62. But if he's in the Exam Room, he
will take three paces up and then down, oscillating between x-coordinates 44
The reason for this discrepancy in pace numbers is the method used to calculate
the teacher's next pace-up or pace-down destination, which is to take his
current x-coordinate and do an XOR $03 on it: see the sections of code at
7D73 and F3DD.
ERIC can usually throw a punch or fire his catapult and be confident that the
impact will send one of the kids or teachers tumbling. However, on certain
occasions, certain characters are invulnerable to ERIC's violence. Those
characters and occasions are as follows:
MR WACKER, when he's looking for ERIC after EINSTEIN has told him what ERIC's up to
MR WACKER, when he's looking for ERIC after finding the pea-shooter on the fire escape
MR WACKER, when he's looking for ERIC to send him home after accumulating 10000 or more lines
MR ROCKITT, when he's looking for ERIC to send him home after catching mumps from ANGELFACE
Little boy no. 10, when he's looking for ERIC to tell him about ANGELFACE, EINSTEIN or BOY WANDER in one of the special playtimes (0xF3, 0xF4, 0xF5)
The reason these characters are invulnerable while looking for ERIC is that
they are under the control of the uninterruptible subcommand routine at
In addition, any boy is invulnerable when he's looking for a seat in a
classroom, because he's under the control of the uninterruptible subcommand
routine at 6C7C.
On those occasions when MR WACKER, MR ROCKITT or little boy no. 10 is looking
for ERIC to deliver a message, ERIC can delay delivery of the message by making
sure that he is writing on a blackboard when the messenger arrives. The
messenger will then wait until ERIC has finished scribbling before commencing
To verify this, use the following POKEs (which make every playtime the
'special' playtime in which little boy no. 10 will come looking for ERIC to
tell him that EINSTEIN is going to grass him up to MR WACKER) and then head for
the nearest blackboard:
If you're feeling very patient, you can use this stalling technique to avoid
having to take part in the special playtime: just stand at the blackboard for
about 20 minutes until the bell rings.
Rather more interesting is that you can use this technique to
The sprite graphic data is split between two base pages: page 0xB9
for the boys and the catapult pellet, and page 0xC9 for the teachers
(see 6D0A). However, the graphic data based in page 0xB9 contains exact
copies of most of MR WACKER's sprites:
This suggests that the original plan was to have the graphic data for every
character based in page 0xB9, but space ran out while adding MR WACKER's
sprites, so the graphic data for him and the other teachers had to go to page
Note the incorrect tile at the bottom right of animatory state 0x51, and the
corresponding incorrect tile at the bottom left of animatory state 0xD1. An
examination of the tile references used to build these sprites reveals
The numbering of the tiles suggests that the bottom-right tile of animatory
state 0x51 was originally 0x51 (not 0x0D), and the bottom-left tile of
animatory state 0xD1 was originally 0xD1 (not 0x8D). If those changes are
made (POKE 47185,81: POKE 45265,209), the shoe on MR WACKER's back foot takes a
So why didn't copies of tiles 0x51 and 0xD1 from page 0xB9 (which seem to
finish MR WACKER's back foot better than tiles 0x0D and 0x8D do) make their
way into page 0xC9? The most likely answer is lack of space: there are no
unused sprite tiles based in page 0xC9, and tiles 0x0D and 0x8D are similar
enough to tiles 0x51 and 0xD1 to make reasonable substitutes.
Points for a punching or a pelleting
ANGELFACE is unique among the cast of characters in that if ERIC knocks him
over with a punch, 30 points are awarded (see F4C0). In addition, if ERIC
knocks him over with a catapult pellet, 10 points are awarded (see 6D7D). No
points are awarded for knocking anyone else over.
BOY WANDER shoots, ERIC scores
BOY WANDER may be a tearaway, but sometimes his impulsive nature can be more of
a help than a hindrance. If he lets rip with his catapult and the pellet knocks
ANGELFACE for six, you score 10 points - just as if ERIC had decked the bully
himself. The reason for this is that the section of code at 6D79 does not
bother to check whose pellet has collided with ANGELFACE's head. (The check for
pellet ownership was added in Back to Skool, though.)
It's also possible for one of BOY WANDER's pellets to bounce off a teacher's
head, hit a shield, and make it flash - scoring even more points - but that
would be a rare occurrence indeed.
When ANGELFACE is throwing his fists around in hopes of landing a sweet one on
somebody's jaw, his fist-throwing actions are under the control of the
continual subcommand routine at 6F1E, which checks whether there are any
potential victims within punching distance. One interesting feature of this
routine is that it neglects to check little boys 8-11. Are these four boys
ANGELFACE's secret best friends, or his most dangerous enemies?
Though the routine does not check little boys 8-11, if any one of those boys
happens to be within range when ANGELFACE lashes out, he will still go down,
because the routine at 6F99 does a full check.
To get rid of ANGELFACE's favouritism and make the routine at 6F1E check all
11 little boys:
Typically, when a teacher arrives at the classroom doorway to start the lesson,
the boys will rush to the back seat and sit down. However, if a boy is late for
class in the Map Room or Exam Room - that is, he arrives at the doorway after
the teacher already has - then he will take some other seat (as shown below),
depending on where his command list sends him.
The reason this happens to a latecomer is that he doesn't get a chance to walk
around before having to find a seat and sit down, because the teacher has
already arrived, the corresponding signal has already been raised, and so the
routine at 62D7 moves straight to the next command in the command list:
6CA0 (find a seat and sit down). That command makes the boy move forward to
the next seat if he's facing left (which is the case if he's just entered the
Map Room or Exam Room), or walk to the back of the classroom if he's facing
right. When the boy does get a chance to walk around first, he ends up facing
right before that command kicks in, and then keeps moving right to the back of
Note that BOY WANDER always tries to sit in the back seat in the Exam Room,
because after entering that room he goes to the blackboard first, and then
walks to the middle of the room, at which point he is facing right.
This unusual seat selection does not happen in the Reading Room or White Room,
because the boy is facing right when he arrives in the classroom, and so keeps
moving right to the back of the class.
The mystery of the unused status flag
Bit 6 of ERIC's status flags at 7FFB is unused: it's always 0. However, the
routines at 657F (down), 65E4 (up) and 6652 (left) check the flag and
act on the result.
657F (down) checks bit 6 early on. If it's set, a jump is made over the code
that checks whether ERIC is on or near a staircase, straight to the code that
moves ERIC left or right (depending on which way he's facing).
65E4 (up) does the same, which suggests that bit 6 may once have been set or
reset elsewhere to indicate whether ERIC is on a staircase.
However, 6652 (left) suggests otherwise. It checks bit 6, and if it's reset,
a jump is made over some code that looks as if it was once used to adjust
ERIC's animatory state in some way: see 668A.
What was this flag used for originally? The mystery may never be solved.
The mystery of the unused MSB
Byte 0x79 of a character's buffer is unused and always zero. However, the
character-moving routine at 6226 checks whether there is a routine address
MSB in byte 0x79, and if it finds one, copies it to byte 0x70 (which
otherwise holds the MSB of the address of the uninterruptible subcommand
routine that's currently in use).
What could this mechanism - which seems to provide for a sort of secondary
uninterruptible subcommand - have been used for while the game was in
development? We'll probably never know.
When ERIC walks, fires his catapult, throws a punch, is knocked out, or
receives lines, the accompanying sound effects are played with interrupts
enabled, which means they are affected by keys being held down. This is
especially noticeable with the lines-giving sounds, which are somewhat longer
than the others. To make them even longer:
There are 64 periods in the main timetable: 26 playtimes, 4 dinner
periods, and 34 lesson periods (when ERIC is supposed to be in either a
classroom or the Revision Library).
In the 34 lesson periods, ERIC is scheduled to be in the White Room 11 times,
the Reading Room 8 times, the Map Room 6 times, the Exam Room 4 times, and the
Revision Library 5 times.
ERIC has 8 classes with MR WACKER, 8 classes with MR ROCKITT, 7 classes with MR
WITHIT, and 6 classes with MR CREAK.
ERIC has 5 classes with MR ROCKITT in the White Room (which is more than any
other teacher/classroom combination), but only one class with MR WACKER in the
White Room and only one class with MR ROCKITT in the Exam Room.
MR WACKER is on dinner duty for two of the dinner periods, and MR WITHIT is on
duty for the other two.
MR ROCKITT and MR WITHIT are the busiest teachers, each teaching a class in 29
of the 34 lesson periods. MR WACKER is the laziest teacher, teaching a class in
only 26 periods.
MR WACKER teaches most often in the Exam Room (13 times); MR ROCKITT teaches
most often in the White Room and the Exam Room (12 times each); MR WITHIT
teaches most often in the Map Room (19 times); and MR CREAK teaches most often
in the Reading Room (17 times).
Every boy is taught at least 3 times by each teacher, and at least 3 times in
each classroom. However, little boys 2, 3, 4, 6, 7, 8 and 9 are - unlike all
the other boys - never in the Revision Library during a lesson period.
ANGELFACE spends more lesson periods in the Revision Library than any other boy
(9 periods compared to BOY WANDER's 7 and ERIC's 5).
During playtime, the teacher most likely to be found pacing up and down in the
staff room is MR CREAK, who spends 23 of the 26 playtimes in the main
timetable in that room (the three exceptions being those playtimes where the
little boys stampede around the skool). The teacher least likely to be found in
the staff room is MR WACKER, who spends only three playtimes there; the other
23 playtimes he divides between his study (3 times) and walking around the
BOY WANDER spends most of his playtimes (16 out of 26) in search of clean
blackboards to write on.
ANGELFACE and EINSTEIN spend every playtime wandering around the skool from one
randomly chosen location to another. The 11 little boys, however,
split their playtimes between wandering around the skool and walking up and
down in one of the four playtime locations (Revision Library, fire escape, gym
and big window) until the bell rings.
The playtime probabilities described here are all subject to alteration by the
fact that, three times out of eight, a playtime in the main timetable is
replaced with a 'special' playtime (0xF3, 0xF4 or 0xF5)
chosen at random (see 6E33).
When demo mode or a new game starts, the timetable index is always
0x00, 0x10, 0x20 or 0x30 (which are
all playtime, of course).
When demo mode starts for the first time after the game has loaded, the
timetable index is 0x10. When a new game is started as soon as
possible after the game has loaded, the timetable index is 0x20.
Also note that playtimes 0xFE and 0xFF are used exclusively as the
second playtime in double playtime periods. There's nothing special about those
playtimes, except that their numbers (0xFE, 0xFF) are easily checked by the
code at 66F8.
Understandably, ERIC is always eager for playtime to come, but the number of
lesson or Revision Library periods he has to tolerate between each break varies
between one and three throughout the main timetable.
There is one period between playtimes at timetable indexes 0x0D and 0x0F
There are two periods between all the other playtimes (not counting dinner periods)
Always a dull playtime in demo mode
Special playtimes - the ones where ERIC must avoid contact with ANGELFACE,
prevent MR WACKER from getting to the fire escape before BOY WANDER, or prevent
EINSTEIN from making it to the head's study - never happen in demo mode (see
F905). Which makes sense, because otherwise the user would have to press 'U'
to signify understanding after being told what BOY WANDER, EINSTEIN or
ANGELFACE is up to, and then press another key to exit demo mode.
The graphic data contains unused sprites of the main kids sitting down with a
Were these used while the game was in development? We'll probably never know.
The board-wiping routine at 71DC checks whether BOY WANDER (as opposed to a
teacher) is wiping the board, and executes a different code path
accordingly. However, BOY WANDER never makes use of this ability in the game
that was released. Did he use it while the game was in development? Again,
we'll probably never know.
Among the graphic data for the boys, there are four unused sprites of ANGELFACE
that show him with his arm up as if writing on or wiping a blackboard:
Were they used while the game was in development? Yet again, we'll probably
Teachers don't give ERIC lines if they see him writing on a blackboard (unlike
Back to Skool, where they do), but they might give him lines if EINSTEIN
grasses on him for writing on the blackboard (unlike Back to Skool, where -
because of a bug - EINSTEIN never grasses on ERIC for writing on the
Save the duster
There are code remnants in the board-wiping routine at 71DC that make a
teacher skip wiping the blackboard if it's already clean. The POKEs to
re-enable this code are:
POKE 29151,79: POKE 29152,6
However, the code that would make the teacher walk to the middle of the
blackboard after deciding not to wipe it is missing, so if you try these POKEs,
expect to see some oddness during lessons where the board starts off clean.
WACKER loves EINSTEIN's tales
MR WACKER never gives EINSTEIN lines for telling tales (see 7CE0). Is WACKER
merely gullible, a firm believer in the virtue of snitching, or both?
The first letter of the safe combination code (MR WACKER's) is always in the
range A-O (see F855). Did WACKER never learn the alphabet from P to Z when
he was at skool?
WHICH BATTLE OCCURRED IN 1800?
Among the 21 battle dates that comprise MR CREAK's history curriculum, 1800
makes no appearance. But perhaps it was not always so: see E4E8. We can only
speculate which battle from that year EINSTEIN would have chosen for his
There is evidence that MR WITHIT used to be rather more verbose with his
blackboard scribblings, but was edited before the game was released. See
'MANCHESTER MONSOONS' at E800, which was probably 'WHY IT RAINS IN
MANCHESTER' at some point (see Alternative differences). Likewise, 'THE
PEAKS OF PERU' at E840 may once have been expressed less tersely (or been
about something other than PEAKS). Finally, which rain-forest other than
Glasgow's could WITHIT have been writing about at E860?