PROGRAM LINES:
==============

10 init (9000)
20 main menu (9400), branching
30 (IF SCREEN NEEDS CLEARED) set editor mode, clear screen (1550), maze border (1000)
35 (IF MAZE NEEDS REDISPLAYED) read map (1700), display title, display map # (1800) and free mem (1820), display maze (1400)
40 (IF ONLY SUMMARY LINE WAS CHANGED) display controls, editor menu (9650), erase summary line (9550), branching
90 (START MAP EDITING) set changes to 0
100 (CONTINUE MAP EDITING) put cursor down (1200), reset keyboard
105 display editor summary, go to main loop (385)
150 game mode; restore player stats; clear screen, draw maze border
160 game screen (9700); draw player

Main loop:
200 key commands
280 saving player location, exit to main menu (20)
300 typing into map
380 space key
 385 set move mode then back to main loop
400 moving/drawing
 420 delete special
 450 (game mode) bump!
 460 (game mode) specials
500 moving left (map goes right)
550 moving right (map goes left)
600 moving up (map goes down)
650 moving down (map goes up)
700 exiting map-drawing (need: SA)
 - inner use: A$
 - call: 1350, 1095
750 browse map (need: NM, ID)
 - manage: N
 - inner use: I, J (cursor coords), A$
 - call: 1090, 1800, 1200
800 draw specials
 - inner use: A (1 = going up, -1 = going down), B (1 = goal, 0 = stairs)
 - call: 1780, 1090
 850 stairs up / goal (up) (A=1)
  880 move map to reserve, load destination map, check if blocked, load current map (for colors), recall map from reserve
  900 if up, then 905, if down, create top of stairs, then 915
  905 create bottom of stairs or goal, then 910 or 920
  910 create top of stairs (need: A (1 = don't))
  915 create bottom of stairs, then store (940)
  920 create top of goal (need: A (1 = don't))
  930 update NM, then...
  940 store map, then back to editor
 950 stairs down (A=-1), check if bottommost level
970 volume
980 set player starting pos

Subroutines:
1000 SUB: draw maze border (need: XS, YS, W, H)
 = temp fix: uses only black color
 - inner use: I
1050 wait I seconds (need: I)
1090 SUB: wait for a key
 1095 SUB: without text
 - set: A$
1100 create filled M$, put spc to pos Z, create C$() if not exists (need: W$, M, Z, E$)
 1110 SUB: create 255-chars M$ (need: W$)
 - set: M$
 - inner use: I
1200 SUB: move cursor to position (need: I, J)
 - set: CH, CL
1250 
1300 message to top of maze display (need: A$)
1320 SUB: clear message from top of maze
 - need: YS
1350 SUB: remove cursor from screen (need: C)
1400 draw maze (need: XS, YS, M$, Z, HP, M, W, S, XE, YE, X, Y, P$)
 - inner use: I, J
1450 draw maze ANYWHERE on/off-screen (need: A, B (coord))
 - inner use: I
1500 SUB: set screen colors and current ink (need: DATA pointer)
 - set: C$()
 - inner use: I, J
1550 SUB: clear screen, set ink (need: C$(1))
1600 SUB: print A$ centered; extra line feed (need: A$)
1650 
1700 SUB: read map, alternatively create a new one (need: N, NM, P)
 - set: M$, W$, E$
 - inner use: I, A$, DATA pointer
 - call: 1100, 1500
1750 SUB: move map (M$, W$, E$) to reserve (MZ$, WZ$, EZ$)
1760 SUB: recall map (M$, W$, E$) from reserve (MZ$, WZ$, EZ$), delete reserve
1780 SUB: check current map pos for special chars (need: M$, Z)
 - set: A$ (current pos char)
 1790 SUB: check if A$ is a special char (need: A$)
 - set: I (1 = blocked)
1800 SUB: display map number (need: N)
1820 SUB: display free memory (in maps) (need: FNME(0))
1850 
1900 SUB: poke J instances of RETURN to key buffer (need: J)
 - inner use: I
1950 
2000 filter A$ (need: A$)
 - spc, shift-spc remains, double quotes filtered out
 - inner use: A (ASC code of A$)
2050 

3000 store map (need: CO, M$, M (0 means no map matrix storing), C$(), SP$ (optional commands before relaunching))
 - inner use: A$, I (first DATA line #), J, DATA pointer
 - max. random text: 24 chars
 - call: 1350, 1900
>3010 without top message
 3065 set line 9100
>3070 (optional commands):GOSUB 9000:GOTO CO

4000 set up dimensions
4100 set up specials (need: SU$, SD$, GU$)
>4105 skip clear screen, title, maze border and maze
 - set: DATA pointer
 - inner use: J, IS, I2, B$, A$, B (specials type)
 - call: 9600, 1400, 9550, 9200, 1095, 2000
 4290 SUB: SP$ creator
4300 delete topmost map
4400 map appearance
 - inner use: B (board #, 1-4, in 2 bg=ink always...), I$(3-4)
 4400 check if an already stored map
 4410 generate color tables
>4440 redraw texts
>4480 display wall and floor char
>4490 display instructions
 4500 reset ink changes
 4505 fields branching
 4550 fields controls
 4620 store/back to menu
 4650 change chars
4800 randomly delete walls (need: M, M$, W$, E$)
 - set: SA
 - inner use: I, J
 - call: 9550, 1400, 1095
4900 edit texts
 5000 edit line
 - set: IM
 - manage: SA, I$(), IS, L
 - inner use: I, J, DATA pointer, B$ (current text), B (current text length), U (SA reserve)
 - call: 1550, 9550, 9220
 5060 SUB: change all spaces to cursor right chars in B$
 - inner use: I
 5100 SUB: create DATA line bundle from 2 adjacent I$()
 - need: I (first I$() index), J (base DATA line number), I$()

5200 SUB: edit B$ in line J from pos 1 to pos D (need: B$, J, ES$, D)
 clears line after editing
>5205 loop start with updating cursor pos
>5210 loop start with getkey only
 - manage: B$, SA
 - inner use: I (cursor x pos), A$, B (text length), D$ (original text)
 - call: 1200, 1350, 2000 (A)
5300 

6000 save game
 - inner use: U (device #)
 - call: 1095, 1550

8000 game end

9000 SUB: constants and variables init
 - set: (all 'const' and 'begin' class)
 - inner use: I, DATA pointer
 9170 SUB: calculate XS, YS

9200 SUB: menu init and choose (need: DATA pointer, J (fullscreen), IS (initially selected item), C$())
>9220 menu display
 9230 choose
 - set: D$, IM, I$()
 - manage: IS
 - inner use: A (current item is active (0,1)), A$, I
 - call: 9300
9300 display menu item (need: A (active?), I (item #), I$(), J (fullscreen), C$())

9350 menu background effects (need: BG)
 - inner use: B (screen poke)
 - set: IS, A$

9400 SUB: main menu (remembers last selected item)
 - used by: main control (20)
 - inner use: DATA pointer, J
 - manage: IS, I0
 - call: 9200
9450 SUB: tag
9500 SUB: display read text (need: DATA pointer)
 - inner use: A$
 - call: 1500, 1600
9550 erase summary line (need: ES$)
9610 sub-editor screen
 - set: DATA pointer
 - inner use: I
 - call: 1600
9650 editor menu (remembers last selected item)
 - set: DATA pointer
 - inner use: J
 - call: 9200
9700 SUB: game screen
 - call: 1700, 1400, 1320
9750 SUB: change B$ to D$ in M$ (need: M$, D$, B$, C$())
 - inner use: I
 - manage: M$
 - set: J (changed map)
 - call: 1400, 1095
9770 SUB: get 

9800 intro
 - set: N
 - inner use: A, B
 - call: 1700, 1450
 Subroutine:
 9990 delete line #I to the top and bottom; make line 12 solid

Data:
10000 title colors, text
10010 title menu text
10020 editor colors, text
10030 editor menu text (max. 18 chars)
10040 game mode colors, text
10050 specials menu text
10100 random text for "dangerous" actions, max. 24 chars

20000 maps (max 76 chars per DATA line)
 starting DATA line = 19995 + N*5
 each new block of 76 bytes of map get +8 bytes (255=76+76+76+27)
 max map mem = 255 chars map data + 8 bytes * 5 DATA lines + 23 bytes parameters
 = 318 bytes per map


VARIABLES:
==========

const C cursor poke address (65292)
const C$ ink color chars
const ES$ ESC char
const G$ common game key commands string (left-right-up-down-spc-esc-,-.)
const K keyboard buffer size address (239)
const K$ common key commands string (left-right-up-down-spc-esc-del-enter-home)
const QU$ double quote char

A,B,D,I,J short-term (loop) variables
menu- BG background effects (0,1)
begin BP bottom-right maze corner poke address
editr CH cursor address high
editr CL cursor address low
editr CO continue at which line after storing map
begin DE number of demo map
begin FNME() free memory in maps
begin H maze screen height (5-7-9-11-13-15)
begin HH half of maze screen height-1 (7)
begin HM half of maze minus half line offset (HH*W-O = 111)
begin HP half of maze plus half line offset (HH*W+O = 127)
begin I0 main menu selected item
begin I1 editor menu selected item
edit- I2 specials menu selected item
menu- ID selected dir on menu item (-1,0,1)
menu- IM menu items max
menu- IS number of menu item selected (0:esc, 1-...)
begin L lines spacing in menus (1 in text editor, 2 elsewhere)
begin L0 link poke data (2030)
begin L1 link poke data (2031)
begin L2 link poke data (2032)
begin M maze string length (255)
menu- MO current mode (0:edit, 1:play)
begin N number of current maze map (1-nnn)
begin NM number of stored maze maps (0-nnn)
begin O XS->X offset (8)
begin P number of map pieces in DATAs (1-4)
begin PN Player saved map # (1-nnn)
begin PZ Player saved pos in maze string (1-255)
begin S stop pos in maze string (240)
editr SA changes were made to the actual map/menu (0,1)
begin TP top-left maze corner poke address
play- U previous player pos (see Z) / SA reserve (5000)
begin V sound volume (0-8)
begin W maze screen width (5-7-9-11-13-15-17)
begin X player screen x coord (10)
begin XE maze screen right side x coord (XS+W-1 = 18)
begin XS maze screen left side x coord (8-7-6-5-4-3-2)
begin Y player screen y coord (12)
begin YE maze screen right side y coord (=YS+H-1 = 19)
begin YS maze screen left side y coord (10-9-8-7-6-5)
begin Z current pos in maze string (1-255, def:1)

A$,B$ short-term string variables
begin BT$ set current screen pos as window bottom, go to top and set window top
menu- C$(0,1) de/selected item color; 1: also wall color
editr D$ current drawing char
editr EZ$ empty char reserve
menu- I$(1-14) menu item names, short-term string array
start M$ current maze (length: 255)
editr MZ$ maze reserve (length: 255)
spec- SP$ special parameters for after map storing
editr WZ$ wall char reserve

Characters (6):
begin E$ current (map) empty char
begin GU$ goal (up) char
begin P$ player char
begin SD$ stairs down char
begin SU$ stairs up char
begin W$ current (map) wall char


SCREEN LINES DATA:
==================

          111111111122222
0123456789012345678901234

654321076543210765432107
\_2030/\_2031_/\_2032_/\_2033
.....xxxxxxxxxxxxxx..... H=15
     3    255     240
......xxxxxxxxxxxx...... H=13
     1    255     224
.......xxxxxxxxxx....... H=11
     0    255     192
........xxxxxxxx........ H=9
     0    127     128
.........xxxxxx......... H=7
     0     63       0
..........xxxx.......... H=5
     0     30       0

          111111111122222
0123456789012345678901234
aaaAaaaAaaaA BbbbBbbbBbbb
...AaAaAaAaA BbBbBbBbB...
........AAAA BBBB........