the next line of the program will be run FOR {num} = {number} TO {number} [STEP {number}] ... NEXT (num) creates a loop where the numeric variable (num) runs from start number to end number in increments of number (STEP). If step is omitted, 1 is assumed Error Messages /0 division by zero AO file specified is already open BS bad subscript. subscript is out of DIM range CN can't continue (see CONT command) DD attempt to redimension an array DN invalid device number DS direct statement error (program has no line numbers) FC illegal function call: function contains a value that is out of range FD bad file data: attempt to read a number into a string value, etc. FM bad file mode, attempt to INPUT data to a file open for OUTPUT, etc. ID illegal direct: the specified command can only be run in a program IE input past end of file. See EOF IO input/output error LS long string: strings can only have 255 characters NF NEXT without FOR NO file not open OD out of data: attempt to read beyond the last DATA in the program OM out of memory OS out of string space: see CLEAR OV overflow: the number is out of range RG RETURN without GOSUB SN syntax error ST string operation too complex TM type mismatch (A$=3, A="CAT") UL attempt to GOTO or GOSUB to a line that doesn't exist Documented ROM subroutines There are a few subroutines available for machine language programs in the Color BASIC ROM that are available for general purpose programming. POLCAT address [$A000]: polls keyboard for a character CHROUT address [$A002]: outputs a character to screen or device CSRDON address [$A004]: starts cassette and prepares for reading BLKIN address [$A006]: reads a block from cassette BLKOUT address [$A008]: writes a block to cassette JOYIN address [$A00A]: reads joystick values References Notes Getting Started With Color BASIC, 1980, Tandy Corporation. Publication #8749266 Color Computer Disk System (Tandy), 1981, Tandy Corporation. Publication #8749470-BCo Getting Started With Extended Color BASIC, 1984, Tandy Corporation. Publication #811013700A Color Computer 3 Extended Basic (Tandy), 1986, Tandy Corporation. Publication #81101910A TRS-80 Color Computer Discontinued Microsoft BASICs BASIC programming language family Microsoft programming languages