Peeks, Pokes and Pointers

Apple(R) Zero-Page
DECIMAL_______________________________________________________________HEX
32 Text Window Left-Edge (0-39 / normal is 0) ....................... $20
   Example: POKE 32, X freezes the left X columns of text.
   Warning: Don't let PEEK(32)+PEEK(33) exceed the screen width.
33 Text Window Width (1-40 or 1-80 / normal is 40 or 80) ............ $21
   Note: POKE 33,33 scrunches listings to remove extra spaces.
34 Text Window Top-Edge (0-23 / normal is 0) ........................ $22
35 Text Window Bottom (1-24 / normal is 24) ......................... $23
36 Horizontal Cursor-Position (0-39) ................................ $24
   Examples: If PEEK(36)=X, then the cursor is in column X+1.
   POKE 36,X puts the cursor in column X+1 (useful with 80-columns,
   for positioning the cursor beyond the 40-column limit of HTAB).
   Note: POKE 1403,X works similarly -�€� and more predictably.
37 Vertical Cursor-Position (0-23) .................................. $25
   Examples: If PEEK(37)=V, then the cursor is on text line Y+1.
43 Boot Slot*16 (after boot) ........................................ $2B
44 Lo-Res Line End-Point ............................................ $2C
48 Lo-Res COLOR*17 .................................................. $30
50 Text Output Format ............................................... $32
   POKE 50, 63=INVERSE. POKE 50, 255=NORMAL,
   POKE 50, 127=FLASH (for ASCII 64-95).
51 Prompt-Character ................................................. $33
   Note: POKE 51,0: GOTO line# will prevent a false "Not Direct Com-
   mand" message caused by an immediate GOTO line# command.
78-79 Random-Number Field ........................................ $4E.4F
103-104 Start of Applesoft Program ............................... $67.68
   To Load a program at a non-standard location LOC --
   POKE LOC-1. 0: POKE 103, LOC-INT(LOC/256)*256:
   POKE 104, INT(L0C/256)   Then LOAD PROGRAM
   Note: FP (DOS 3.3 only) sets start-of-program to normal 2049 ($801).
105-106 LOMEM .................................................... $69.6A
   Note: LOMEM is the Start of Variable-Space, equivalent to End-of-
   Program (approx.) unless changed with the LOMEM: command.
107-108 Start of Array-Space ..................................... $6B.6C
109-110 End of Array-Space ....................................... $6D.6E
111-112 Start of String-Storage .................................. $6F.70
115-116 HIMEM .................................................... $73.74
   Note: HIMEM-1 is the highest address available for use by an Applesoft
   program. May be changed with the HIMEM: command.
117-118 Line-Number Being Executed ............................... $75.76
119-120 Line-No. Where Program Stopped ........................... $77.78
121-122 Address of Line Executing ................................ $79.7A
123-124 Current DATA Line-Number ................................. $7B.7C
125-126 Next DATA Address ........................................ $7D.7E
127-128 INPUT or DATA Address .................................... $7F.80
129-130 Last-Used Variable Name .................................. $81.82
131-132 Last-Used-Variable Address ............................... $83.84
175-176 End of Applesoft Program ................................. $AF.B0
214 RUN Flag ........................................................ $D6
   Example: POKE 214, 255 makes any command RUN a program.
216 ONERR Flag ...................................................... $D8
   Example: POKE 216, 0 cancels the ONERR function.
218-219 Line-Number of ONERR Error ............................... $DA.DB
220-221 ONERR Error Address ...................................... $DC.DD
222 ONERR Error Code ................................................ $DE
   DOS 3.3 and PRODOS
     1: Language Not Available
     2 or 3': Range Error
     3: No Device Connected2
     4: Write-Protected
     5: End of Data
     6: File' or Path'' Not Found
     7: Volume Mismatch'
     8: I/O Error
     9: Disk Full
    10: File Locked
    11: Syntax Error' or Invalid Option''
    12: No Buffers Available
    13: File Type Mismatch
    14: Program Too Large
    15: Not Direct Command
    17: Directory Full''
    18: File Not Open''
    19: Duplicate File Name''
    20: File Busy''
    21: File(s) Still Open''

    'DOS 3.3 only ''ProDOS only

   APPLESOFT
     0: ?Next Without For
    16: ?Syntax Error (FP)
    22: ?Return Without Gosub
    42: ?Out of Data
    53: ?Illegal Quantity
    69: ?Overflow
    77: ?Out of Memory
    90: ?Undef'd Statement
   107: ?Bad Subscript
   120: ?Redim'd Array
   133: ?Division by Zero
   163: ?Type Mismatch
   176: ?String Too Long
   191: ?Formula Too Complex
   224: ?Undef'd Function
   254: ?Re-Enter
   255: (control-C Interrupt)
224-225 X of Last HPLOT (0-279) .................................. $E0.E1
226 Y of Last HPLOT (0-191) ......................................... $E2
228 HCOLOR Code ..................................................... $E4
   0=0, 42=1, 85=2, 127=3, 128=4, 170=5, 213=6, 255=7
230 Hi-Res Plotting Page ............................................ $E6
   POKE 230,32 selects Page 1. POKE 230,96 selects Page 3.
   POKE 230,64 selects Page 2.
231 SCALE ........................................................... $E7
   Note: SCALE=0 is equivalent to a SCALE of 256.
232-233 Shape Table Start Address ................................ $E8.E9
234 Hi-Res Collision-Check .......................................... $EA
   Example: XDRAW a shape. If PEEK(234)=0 then the shape
   started at a non-black hi-res point.
241 SPEED ........................................................... $F1
   Note: PEEK(241) is 256 minus the current SPEED.
243 FLASH Mask ...................................................... $F3
249 ROT ............................................................. $F9

Display Switches
DECIMAL (with negative equivalent)________________________HEX
49232 (-16304) Graphics ............................... $C050
49233 (-16303) Text ................................... $C051
49234 (-16302) Full-Graphics .......................... $C052
49235 (-16301) Split-Screen ........................... $C053
49236 (-16300) Page One ............................... $C054
49237 (-16299) Page Two ............................... $C055
49238 (-16298) Lo-Res ................................. $C056
49239 (-16297) Hi-Res ................................. $C057
   Note: Activate display switches by Poking each location.
   Example: POKE 49232,0 switches to Graphics display.

Keyboard, etc.
DECIMAL (with negative equivalent)________________________HEX
49152(-16384)ReadKeyboard ............................. $C000
49168 (-16368) Clear Keyboard ......................... $C010
   Example: 10 KEY=PEEK(49152): IF KEY<128 THEN 10
20 POKE 49168, 0 30 PRINT "KEY: "; CHR$(KEY-128)
49200 (-16336) Click Speaker .......................... $C030
   Example: FOR A=1 TO 99: BUZZ=PEEK(49200): NEXT
49249 (-16287) Button #0 .............................. $C061
   Paddle-0 Button or Open (left) Apple key.*
49250 (-16286) Button #1 .............................. $C062
   Paddle-1 Button or Closed (right) Apple key*
49251 (-16285) Button #2 .............................. $C063
   *Example: If PEEK(49249+P) is greater than 127, then
   Paddle Button #P is being pressed�€r it's not connected.

DOS 3.3 Pokes
(assume DOS loaded in main memory)___________________________
POKE 40193, PEEK(40193)-N: CALL 42964
   Moves DOS buffers down N*256 bytes.
POKE 44452,N+1: POKE 44605,N
   Allows N file names before catalog pause.
POKE 44460,88: POKE 44461,252
   Clears screen before catalog.
POKE 44505,234: POKE 44506,234
   Exposes deleted file names in catalog.
POKE 44596, 234: POKE 44597, 234: POKE
   44598, 234 Cancels catalog pause.
POKE 49107,234: POKE 49108,234: POKE
   49109, 234 Prevents language card reload.
POKE 49384,0 Stops drive motor.
POKE 49385,0 Starts drive motor.

Notes _______________________________________________________
Apple's main memory consists of 65,536 bytes, numbered
zero to 65535. Every byte has a value in the range 0-255.
* You may Peek (look at) the value in byte number-B with
  the command -�€� PRINT PEEK(B)
* You can usually Poke a new value-V into byte-B with the
  command -�€� POKE B,V
Values higher than 255 must be stored in two bytes:
* To look at the value in consecutive bytes B1-B2-
  PRINT PEEK(B1)+PEEK(B2)*256
* To Poke a new value V (D-65535) into bytes B1-B2-
  POKE B1, V-INT(V/256)*256
  and POKE B2, INT(V/256)
Note: Since almost any memory location can be Peeked or
Poked, program listings can reveal thousands of Peeks and
Pokes not listed on this chart. Pokes are often used to write
machine-language routines that may be activated with the
CALL command -- the possibilities are infinite.
_____________________________________________________________
Let A=PEEK(64435) and B=PEEK(64448).
If A=6 and B=0 then Apple IIc.
If A=6 and (B>223 AND B<240) then Apple IIe.
If A<>6 then Apple II or II+.
_____________________________________________________________

Page-3 DOS Vectors
DECIMAL____________________________________________________________HEX
976-978 Re-enter-DOS Vector ................................. $3D0.3D2
1010-1012 Reset Vector ...................................... $3F2.3F4
   Example: POKE 1012, 0 makes Reset boot.
   (POKE 1012,56 to restore normal Reset function,)
1013-1015 Ampersand Vector .................................. $3F5.3F7
   Examples: POKE 1014, 165: POKE 1015, 214 makes "&" LIST.
   POKE 1014, 110: POKE 1015, 165 makes "&" CATALOG.
   POKE 1014, 18: POKE 1015, 217 makes "&" RUN.
1016-1018 Control-YVector.................................... $3F8.3FA

DOS 3.3 Locations
DECIMAL____________________________________________________________HEX
        (All values assume DOS is loaded in main memory.)
42350 Catalog-Routine .......................................... $A56E
   Example: CALL 42350 catalogs a disk.
40514 Greeting Program Run-Flag ................................ $9542
   POKE 40514,52 and INIT a disk. When booted, DOS will attempt to
   BRUN the greeting program. POKE 40514,20 for EXEC.
43140-43271 Commands ...................................... $A884.A907
43378-43582 Error Messages ................................ $A972.AA3E
43616-43617 Last Bload Length ............................. $AA60.AA61
43634-43635 Last Bload Start .............................. $AA72.AA73
43624 Drive-Number ............................................. $AA68
   Example: POKE 43624, D changes disk input/output to Drive D.
43626 Slot-Number .............................................. $AA6A
   Example: POKE 43626, S changes disk input/output to Slot S.
43698 Control-D Command Character .............................. $AAB2
44033 Catalog Track Number ..................................... $AC01
45991-45998 File-Type Codes ............................... $B3A7.B3AE
45999-46010 Disk Volume Heading ........................... $B3AF.B3BA
46017 Disk Volume Number ....................................... $B3C1

ProDOS(TM) Locations
DECIMAL____________________________________________________________HEX
48944 Slot/Drive Value.......................................... $BF30
   If PEEK(48944) is greater than 127 then Drive 2, otherwise Drive 1.
47313-47422 Commands ...................................... $B8D1.B93E
48840-48841 Last Bload Length ............................. $BEC8.BEC9
48825-48826 Last Bload Start .............................. $BEB9.BEBA

Useful Calls
DECIMAL (add 65536 for positive equivalent) _______________________HEX
CALL-25153 Reconnect DOS 3.3 ................................... $9DBF
CALL-3100 Reveal hi-res page 1 ................................. $F3E4
CALL-3086 Clear hi-res screen to black ......................... $F3F2
CALL-3082 Clear hi-res to last color Hplotted .................. $F3F6
   Example: HGR2: HCOLOR=5: HPLOT 0,0: CALL-3082
CALL-2613 Hi-res coordinates to Zero-Page ...................... $F5CB
   Example: The X and Y starting coordinates of the next shape table
   DRAW or XDRAW may be determined with a CALL-2613. Then
   X=PEEK(224)+PEEK(225)*256 and Y=PEEK(226).
CALL-1438 Pseudo-Reset ......................................... $FA62
CALL-1370 Boot ................................................. $FAA6
CALL-1321 Display all registers ................................ $FAD7
CALL-1184 Clear screen and print "Apple..." ..................,. $FB60
CALL-1036 Move cursor right .................................... $FBF4
CALL-1008 Move cursor left ..................................... $FC10
CALL-998  Move cursor up ....................................... $FC1A
CALL-958  Clear text from cursor to bottom ..................... $FC42
CALL-922  Move cursor down ..................................... $FC66
CALL-868  Clear text-line from cursor to right ................. $FC9C
CALL-756  Wait for any keypress ................................ $FD0C
CALL-678  Wait for a Return keypress ........................... $FD5A
CALL-657  Better Input; commas/colons o.k. ..................... $FD6F
   10 PRINT "NAME (LAST, FIRST) :";: CALL -657
   20 A$= "": FOR X=512 TO 767: IF PEEK(X)<>141
      THEN A$=A$+CHR$(PEEK(X)-128): NEXT X
CALL-468  Memory move .......................................... $FE2C
   A Basic memory move: OS & OE are the Old-location Start & End, and
   NS is the New Start. GOSUB 5000 to execute the move �€�-
     5000 N=OS: LOC=60: GOSUB 5020:
          N=OE: LOC=62: GOSUB 5020:
          N=NS: LOC=66: GOSUB 5020
     5010 POKE 766, 160: POKE 769, 0: POKE 770, 76:
          POKE 771, 44: POKE 772, 254: CALL 768: RETURN
     5020 POKE LOC, N-INT(N/256)*256:
          POKE LOC+1, INT(N/256): RETURN
CALL-415  Disassembler ......................................... $FE61
   Note: Poke start address at locations 58-59 before Call.
CALL-211  Ring bell and print "ERR" ............................ $FF2D
CALL-198  Ring bell ............................................ $FF3A
CALL-151  Enter monitor ........................................ $FF69
CALL-144  Scan input buffer .................................... $FF70
   This example uses CALL -144 to execute a machine
   language routine from Basic (will not work in a subroutine):
     100 A$="300: A9 C1 20 ED FD 18 69 01 C9 DB D0 F6
         60 300G D823G
     110 FOR X=1 TO LEN(A$): POKE 511+X,
         ASC(M|D$(A$.X,1))+128: NEXT
     120 POKE 72, 0: CALL -144
======================================================================
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Micro Software Inc.

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