n88-basic-reference

This translation is a work in progress and does not contain all the commands possible in PC-88 BASICs.

Structures

Labels

A label provides a line reference that can be called by GOTO or GOSUB without having to manually track the line number and update it if it changes.

Example:

10 PRINT "HELLO"
20 GOSUB *WORLD
30 END
40 *WORLD: PRINT "WORLD"
50 RETURN

Commands

ASC

Usage: ASC([char])

Convert the first character of a string to the numeric ASCII index for it.

Examples:

• ASC("X"): Produces 88 (ASCII ‘X’)
• ASC("Administrator"): Produces 65 (ASCII ‘A’)

BEEP

Usage: BEEP <mode>

It beeps.

Examples:

• BEEP: Start beeping.
• BEEP 0: Stop beeping.

BLOAD

Usage: BLOAD [filename] <load address> <,R>

Load a machine-language program.

If load address is omitted, it will be loaded to the address specified when the binary was saved with BSAVE.

Append R to immediately run the program. If a load address is also specified, execution will begin from that address.

Examples:

• bload "2:test.bin",&he000 - Load test.bin from the secondary disk drive, storing it in memory starting at 0xE000.

CALL

Usage: CALL [variable] (,argument 1) (,argument 2) ...

Call a machine-language subroutine. The variable argument holds the address of the subroutine to execute from.

CHR$

Usage: CHR$([index])

Return the shift-JIS character corresponding to an integer character code.

Shift-JIS table for reference

Examples:

• CHR$(&H41) => “A”
• CHR$(&H889F) => “亜”

CINT

Usage: CINT([value])

Convert to a 16-bit signed integer.

Values between -32768 and 37267 are valid, everything else gets an overflow error.

Examples:

• CINT(1.2345) => 1
• CINT(-3.456) => -3
• CINT(56789) => overflow error

CLS

Usage: CLS <mode>

Clear the screen.

Modes:

• 1: Clear text screen
• 2: Clear graphics screen
• 3: Clear both text and graphics screens

CONSOLE

Usage: CONSOLE [scroll start], [scroll number of lines], [display function keys], [colour/monochrome]

Set modes for text screens.

• By specifying the “scroll start” and “scroll number,” you can define the scrolling area (scroll window) on the screen.
• CLS and PRINT CHR$(12) work on this scroll window.
• “Scroll start line” indicates the line from which to start scrolling.
• If you pass 1 to “display function keys,” the programmable function key help will appear on the bottommost line of the display. Passing 0 disables this feature.
• Setting “colour/monochrome” to 1 applies colour text mode, and 0 is monochrome.

Examples:

• CONSOLE 0, 10, 1, 1: Sets the first ten lines as a scroll area and disables function key display.
• CONSOLE , , , 1: Leaves all other settings as they were and enables colour text expression.

CONT

Usage: CONT

Resume execution from a STOP or END statement.

CSNG

Usage: CSNG([number])

Convert a number to a single-precision float.

Examples:

• CSNG(123) => 123
• CSNG(3.14159) => 3.14159
• CSNG(-1E+40) => "Overflow" error

CSRLIN

Usage: CSRLIN

Return the screen row number that the cursor is on.

In 25-line mode, this will be 0-24. In 20-line mode, this will be 0-19.

0 is the topmost row of the screen.

DATE$

Usage DATE$

Variable containing the current date, in YY/MM/DD format.

Examples:

• DATE$ = "85/08/19": Set the computer’s date to August 19, 1985.
• PRINT MID$(DATE$, 4, 2): Print the current month number.

DEF FN

Usage DEF FN[NAME][ARGUMENTS] = [BODY]

Define a function.

Examples:

110 DEF FNDB(X)=X*2
120 PRINT "Twice 10 is";FNDB(10)

DELETE

Usage: DELETE [line number]

Delete a line number from the current BASIC program.

Examples:

• DELETE 90: Delete line 90.

DIM

Usage: DIM [NAME]([size0], [size ...])

Define an array.

If the array described by NAME already exists, you will get a “duplicate definition” error. Use ERASE to remove the variable definition and then you can recreate it.

Examples:

• DIM MT(3,3,3): define a 3D array named MT with 3x3x3 dimensions.

DSKF

Usage: DSKF([drive number]<, parameter>)

Get information on a floppy disk inserted into drive drive number. Note that drive numbers are 1-indexed.

Parameters you can extract are:

• 0 - Maximum track number
• 1 - Number of sectors per track
• 2 - Single sided (0) or double-sided (1) floppy disk
• 3 - Number of clusters per track
• 4 - Number of clusters per floppy disk
• 5 - Track index containing the directory info
• 6 - Number of sectors per cluster
• 7 - Start sector of FAT
• 8 - Last sector of FAT
• 9 - Number of FAT (?)
• 10 - Sector index containing ID

Examples

• DSKF(1) Get remaining capacity of the disk in drive 1.
• DSKF(2, 0)

EXP

Usage: EXP([number])

Raise e to the power specified.

Examples:

• EXP(3) => 20.0855
• EXP(-12) => 6.14422E-06
• EXP(100) => Overflow error

FILES / LFILES

Usage: FILES <disk number>

List the files that are on disk

Examples:

• FILES List the files on the primary floppy disk.
• FILES 2 List the files on the secondary floppy disk.
• LFILES List the files in a linear display instead of columnar.

FIX

Usage: FIX([decimal number])

Convert a decimal number to an integer, and floor it.

Examples:

• A=1.5 FIX(A) => -1

FPOS

Usage: FPOS([file handle])

Get the current position in a file.

Examples:

110 OPEN "2:data" FOR OUTPUT AS #1
120 PRINT FPOS(1)

FRE

Usage: FRE([memory type])

Get free available memory.

Examples:

• FRE(0) - Get free variable space.
• FRE(1) - Get free text space.
• FRE(2) - Get free variable + text space.

GET

Usage: GET [file handle], [variable]

Fetch a line from a file, refreshing any FIELD variables set previously.

Examples:

110 OPEN "2:address" AS #1
120 FIELD #1,30 AS A$,20 AS B$,50 AS C$
130 FOR I=1 TO LOF(1)
140	GET #1, I
150	PRINT "NAME",A$
160	PRINT "TEL",B$
170	PRINT "ADDRESS",C$
180 NEXT I
190 CLOSE:END

GOSUB / RETURN

Usage: GOSUB [line number or label], RETURN <line number>

Jump to a subroutine, or return from one.

RETURNing without GOSUB will throw an error.

Examples:

• GOSUB 1000: Jump to the subroutine at line 1000.
• GOSUB *INVENTORY: Jump to a subroutine following the label *INVENTORY.
• RETURN 100: Return from the subroutine, and continue execution at line 100.

GOTO

Usage: GOTO [line number]

Jump to a line number of the program.

Examples:

• GOTO 1000

HEX$

Usage: HEX$([decimal value])

Convert a decimal integer to hexadecimal.

Examples:

• HEX$(-32768) => "8000"
• HEX$(65535) => "FFFF"

INKEY$

Usage: INKEY$

Get the currently held down key. Does not block. Returns empty string if no key is being held down.

Examples:

110 PRINT "Enter any key to end"
120 A$=INKEY$
130 IF A$="" THEN 110 ELSE END

INP

Usage: INP [I/O port address]

Read data from an I/O port specified by the address

Examples:

• INP(&h02): Read from the keyboard port

INPUT WAIT

Usage: INPUT WAIT [time span], [prompt]<;variables>

Put up an input prompt, but only wait a certain period of time before continuing.

Time span is in tenths of a second, so e.g. 50 is 5 seconds.

Examples:

• INPUT WAIT 100, "Your name";NA$ - Display “Your name” prompt, and wait 10 seconds. When a character string is entered, it goes into the variable NA$.

INSTR

Usage: INSTR(needle, haystack)

Get the index of a substring inside a string. Returns 0 when not found, otherwise a 1-indexed character index of the start of the string.

Examples:

• INSTR("BISCUIT", "CHEESE") => 0
• INSTR("COLUMNS III", "COLUMNS") => 1

INT

Usage: INT([decimal number])

Convert a decimal number to an integer, with rounding.

Examples:

• A=-1.5 INT(A) => -2

INP

Usage: INP([port])

Read data from the Z80 I/O port (0-255) specified by port.

Examples:

• INP(&h33): Read a byte from port 0x33.

KILL

Usage: KILL [filename]

Delete a file from disk.

Examples:

• KILL "2:data" Erase the file named data on the second floppy disk.

LEN

Usage: LEN([string])

Get the length of a string or string variable.

Examples:

• LEN(HELLO$): Get the length of the HELLO$ string variable.
• LEN("HI THERE"): Get the length of the string “HI THERE” (8)

LOAD

Usage: LOAD [filename] <,R>

Load a program from disk.

Examples:

• LOAD "demo" Load the demo program into RAM.
• LOAD "demo",r Load and immediately run the demo program.
• LOAD "2:test.n88" Load the test.n88 program from the second floppy drive.

LOC

Usage: LOC [file handle]

Get the current location in an open file.

Examples:

• LOC(2) Get current location in file handle #2.

LOCATE

Usage: LOCATE [x] [y] <Enable Cursor?>

Move the text cursor around the screen.

Examples:

• LOCATE 0, 0, 0 Move the cursor to the top left of the screen and disable cursor display.
• LOCATE 0, 10 Move the cursor to the left side of the 11th line from the top.

LOF

Usage: LOF [file handle]

Get the size of a file.

Examples:

• LOF(2) Get the size of file handle #2.

MON

Usage: MON

Enter machine-language monitor mode.

Press CTRL+B to return to BASIC.

NAME

Usage: NAME [old file] AS [new file]

Rename a file on disk.

Examples:

• NAME "sumple" as "sample"

NEW

Usage: NEW

Obliterate the current program and start from scratch.

OUT

Usage: OUT [port], [data]

Write data to the Z80 I/O port (0-255) specified by port.

Examples:

• OUT &h54, &h03: Set port $54 (colour palette 0) to $03 (purple.)

PAINT

Usage: PAINT (Wx, Wy) <area colour> <border colour>

Fill the last shape rendered with the provided colour.

Examples:

110 SCREEN 0,0:CLS 3
120 X=INT(RND*639):Y=INT(RND*199)
130 R=RND*50+1:C=RND*6+1
140 CIRCLE(X,Y),R,C
150 PAINT(X,Y),C
160 GOTO 120

Randomly draws filled circles on the screen.

POS

Usage: POS <expression>

Returns the horizontal position of the cursor.

The value returned is an integer up to the character width of the display.

Useful for word wrapping.

expression has no meaning; normally it is 0.

Examples:

• POS(0): Return the horizontal position of the cursor.

OUT

Usage: OUT [I/O address] [value]

Write a value to an I/O port specified by the address.

ROLL

Usage: ROLL [number of pixels]

Scroll the graphic screen upward by the pixel count.

Examples:

• ROLL 16: Scroll upward by 16 pixels.

SAVE

Usage: SAVE [filename] <,A|,P>

Save the current program to a file on disk. If you provide the same name as an existing file, the existing file will be overwritten.

Examples:

• SAVE "myprogram.n88" Save the program as myprogram.n88
• SAVE "myprogram.n88",A Save the program as myprogram.n88 in raw ASCII format.
• SAVE "myprogram",P Save the program as myprogram in an “encrypted binary format” (probably pre-tokenized/compiled?)
• SAVE "2:myprogram.n88" Save the current program as myprogram.n88 on the second floppy-disk drive.

SEARCH

Usage: SEARCH [array] <, start index> <,step>

Find an item in an array, returning the index of the item found.

Examples:

• NUM = SEARCH(A%, 100, 0, 3) - Search the A% array for the value 100, starting at index 0 and stepping 3 indices every time.

SGN

Usage SGN [number]

Get the negative/positive sign of a number.

Examples:

• SGN(0.5) => 1
• SGN(0) => 0
• SGN(-0.5) => -1

SPC

Usage: SPC [number]

Print a certain number of spaces. Useful for aligning screen elements in text mode?

Examples:

• SPC(7) => _ _ _ _ _ _ _ (seven spaces)

VAL

Usage: VAL([string])

Parses a string into a number variable.