Color Basic (non-Extended) Summary

Under construction, more details on the way
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Statements
   AUDIO ON
   AUDIO OFF
   CLEAR n,h               Reserve n bytes for strings, and
                           use only up to address h for BASIC
   CLOAD
   CLOAD name
   CLOSE d
   CLS c
   CONT
   CSAVE name
   CSAVE name,A
   DATA
   DIM
   END
   EXEC
   EXEC address
   FOR .. TO .. STEP .. / NEXT
   GOSUB linenumber
   GOTO linenumber
   IF .. THEN .. ELSE ..
   INPUT
   INPUT #-1
   LIST
   LLIST
   MOTOR ON
   MOTOR OFF
   NEW
   ON .. GOSUB ..
   ON .. GOTO ..
   OPEN m,#d,filename
   POKE addr,value         Save value at address addr, where
                           0 <= addr <= 65535, and 0 <= value <= 255
   PRINT
   PRINT #-1
   PRINT #-2
   PRINT TAB
   PRINT @location
   READ
   REM
   RESET (x,y)
   RESTORE
   RETURN
   RUN
   SET (x,y,c)
   SKIPF
   SKIPF name
   SOUND tone,duration
   STOP

Functions
   ABS(num)
   ASC(str)
   CHR$(charcode)
   EOF(f)
   INKEY$
   INSTR(first,str,substr)
   INT(num)
   JOYSTK(j)                Reads joystick value j:
                                0=left_horiz  1=left_vert
                                2=right_horiz 3=right_vert
   LEFT$(str,length)
   LEN(str)
   MEM
   MID$(str,first,len)
   POINT(x,y)
   RIGHT$(str,length)
   SGN(num)
   SIN(num)
   STR$(num)
   USR(num)                 Calls the machine-language subroutine whose
                            address is stored at addresses 275 and 276
   VAL(str)
   VARPTR(var)

Operators
   ^               Exponentiation
   -,+             Unary negative, positive
   *,/             Multiplication, division
   +,-             Addition and concatenation, subtraction
   <,>,=,<=,>=,<>  Relational tests
   NOT, AND, OR    Logical operators

Error messages
   Abbrev.  Explanation
     /0     Division by zero
     AO     File already open
     BS     Bad subscript - out of range
     CN     Cannot continue
     DD     Redimensioned array
     DN     Device number error
     DS     Direct statement in file
     FC     Illegal function call
     FD     Bad file data
     FM     Bad file mode
     ID     Illegal direct
     IE     Input past end of file
     I/O    Input/Output error
     LS     String too long
     NF     NEXT without FOR
     NO     File not open
     OD     Out of data
     OM     Out of memory
     OS     Out of string space
     OV     Overflow
     RG     RETURN without GOSUB
     SN     Syntax error
     ST     String formula too complex
     TM     Type mismatch
     UL     Undefined line number

ROM subroutines
   NAME   Addr Description
   CSRDON A004 Gets the cassette going and reads the leader
   BLKIN  A006 Reads a block from the cassette
               Must immediately follow CSRDON
               Uses CBUFAD
               returns BLKTYP and BLKLEN, cc.z=1 <-> okay
   WRTLDR A00C Gets the cassette going and writes the leader
   BLKOUT A008 Writes a block to the cassette
               Must immediately follow WRTLDR
               Uses CBUFAD, BLKTYP, and BLKLEN
   CHROUT A002 Output a character to screen or printer
               Uses DEVNUM, character to output in acca
   POLCAT A000 Polls the keyboard for a character
               returns cc.z=1 <-> no key, or acca=key code
   JOYIN  A00A Reads and saves all four joystick values
               returns POTVAL through POTVAL+3

Memory map
   Decimal     Hex       Description
   0-105       0-69      Direct page RAM, OK for use by user ML programs
   106-255     6A-FF     Direct page RAM, used by BASIC
   111         6F        DEVNUM: 0=screen, FE=printer
   125         7D        BLKLEN: number of bytes in a block (0-255)
   126         7C        BLKTYP: block type: 0=header, 1=data, FF=end
   127         7E        CBUFAD: buffer address (two bytes?)
   129         81        CSRERR: cassette error code
   256-273     100-111   Internal use (jump vectors)
   274-276     112-114   Address of USR routine
   277-281     115-119   OK for use by user ML programs
   282         11A       Keyboard alpha-lock: FF=locked, 0=not
   283-284     11B-11C   Keyboard delay constant
   285-337     11D-151   OK for use by user ML programs
   338-345     152-159   Keyboard rollover table
   346-349     15A-15D   POTVAL: Joystick values
   346         15A               Right joystick, left/right value
   347         15B                               up/down value
   348         15C               Left joystick,  left/right value
   349         15D                               up/down value
   350-1023    15E-3FF   Internal use
   1024-1535   400-5FF   Video memory
   1536-32767  600-7FFF  User's BASIC program
   32768-40959 8000-9FFF [Extended Color BASIC]
   40960-49151 A000-BFFF Color BASIC
   49152-65279 C000-FEFF [Program pak memory]
   65280-65535 FF00-FFFF I/O, machine configuration, reset vectors

Back to my top-level CoCo page

  ------------------------------------------------------------------------
12-Jun-98
yakowenk@csx.unxc.edu
(remove all "x"s to get a valid address)
