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A Comparision of Keywords on the ZX80 and ZX Spectrum

Overview

The following is a list of keywords, operators and delimiters used on the ZX80 and ZX Spectrum. The ZX80 has many differences which make comparisons difficult but not impossible. For one thing, the ZX80 does not use floating-point arithmetic like the ZX Spectrum, instead it uses integer based arithmetic. This can make complex mathematics like trigonomety a bit tricky. Programs running under integer based BASIC may run faster than those running under floating-point BASIC, so the ZX80 may actually run some programs faster than the ZX Spectrum.

On the ZX Spectrum and ZX81 a single keyword entry system is used when entering programs into memory, in other words a keyword like PRINT is entered by pressing the P key and the whole keyword will be display without the need to enter the four other letters. On the 128K, +2, +3 and the QL keywords are entered one letter at a time. The ZX80 is unique in that it use a mixture of both. Most of the statements and functions are obtained by pressing a single key (or a single key shifted), but a few of these are typed in character by character. These are called the Integral Functions.

Microdrive commands have not been included as these are totally exclusive to the ZX Spectrum and cannot translated to ZX80 BASIC.

Reference to the ZX80 on this page refers to the ZX80 with 4K ROM. When the ZX80 is installed with an 8K ROM it becomes a ZX81 (mostly).

Commands

Keyword

Meaning

Comments

CLEAR

CLEAR (ZX80 & ZX Spectrum)

CLEAR n (ZX Spectrum)

Result: Clears the screen, deletes all variables, resets PLOT and PRINT positions and clears the GOSUB stack. If a number is specified then RAMTOP is lowered to n.

CLEAR on the ZX80 only deletes all variables.

CONTINUE

CONTINUE

Result: After error report 9 (STOP Statement) or report L (BREAK into program) CONTINUE will execute the next line after the error occurred.

CONTINUE is shortened to CONT on the ZX80 and ZX Spectrum keyboards. Error L on the ZX Spectrum is equivelent to error 0 on the ZX80.

LIST

LIST

LIST n

Result: Display program listing from line n or line 0 is no line number specified.

ZX80 will only display one page before stopping and a new LIST statement with the next line number after the last one displayed must be issued. The ZX Spectrum will display the message 'scroll?' if the listing will not fit onto one page. Pressing 'y' will continue the listing.

LLIST

LLIST

LLIST n

Result: Send program listing from line n (or line 0 is no line number specified) to the ZX Printer.

It is not possible to use an unmodified ZX80 with the ZX Printer.

LOAD

LOAD  (ZX80 only)

LOAD f  (ZX Spectrum)

LOAD f DATA ()  (ZX Spectrum only)

LOAD f DATA $()  (ZX Spectrum only)

LOAD f CODE m,n  (ZX Spectrum only)

LOAD f CODE m  (ZX Spectrum only)

LOAD f CODE  (ZX Spectrum only)

LOAD f SCREEN$  (ZX Spectrum only)

Result: Load program (or code) f from tape into memory.

LOAD is a single comand on the ZX80.
ZX Spectrum has extra options to load dimensional arrays, code direct to memory or a screen to the display file.

MERGE

MERGE f

Result: Merge program f with that already in memory overwriting duplicate program lines.

Not on the ZX80.

NEW

NEW

Result: Deletes program and variables and memory up to and including the address held in the system variable RAMTOP.

Similar on both micros. The ZX Spectrum also preserves the system variables UDG, P-RAMT, RASP and PIP.

RUN

RUN

RUN n

Result: Perform CLEAR and GO TO line n (or line 0 if n not specified).

Same on both micros.

SAVE

SAVE  (ZX80)

SAVE f  (ZX Spectrum)

SAVE f LINE m  (ZX Spectrum)

SAVE f DATA ()  (ZX Spectrum)

SAVE f DATA $()  (ZX Spectrum)

SAVE f CODE m,n  (ZX Spectrum)

SAVE f SCREEN$  (ZX Spectrum)

Result: Save program f to tape from memory.

SAVE on the ZX80 will save a program, variables and system variables to tape.
ZX Spectrum has extra options to save dimensional arrays, code from memory or the display file.

On the ZX Spectrum the item LINE m will RUN a program from line m once loaded. ZX Spectrum filenames only allow up to 10 characters, the ZX80 saves with no filename.

VERIFY

VERIFY f

VERIFY f DATA ()

VERIFY f DATA $()

VERIFY f CODE m,n

VERIFY f CODE m

VERIFY f CODE

VERIFY f SCREEN$ ^*

^*This command will be accepted by the Spectrum but taped SCREEN$ code will fail verification.

Result: Compared program f from tape with that in memory. Error R if verify fails.

Not available on ZX80.

Statements

Keyword

Meaning

Comments

AT

AT x,y

Result: Changes PRINT or INPUT position to x,y.

Not on the ZX80.

BEEP

BEEP x,y

Result: Sound emitted for x seconds at pitch y.

The ZX80 has no sound facility so BEEP in not possible on that micro.

BORDER

BORDER m

Result: Changes screen border colour to m.

It is not possible to change the border on the ZX80.

BRIGHT

BRIGHT n

Result: Sets brightness, n=0 normal, n=1 bright, n=8 transparent.

The brightness of the screen cannot be changed on the ZX80.

CIRCLE

CIRCLE x,y,z

Result: Draws a circle of radius z at position x,y.

High resolution graphics are not possible on the ZX80.

CLS

CLS

Result: Clears the screen.

Same result on both micros.

COPY

COPY

Result: Sends the contents of the screen to the ZX Printer.

It is not possible to use an unmodified ZX80 with the ZX Printer.

DATA

DATA e₁,e₂,e₃, ...

Result: Stores data in a list.

Not on the ZX80. Dimensional arrays and LET should be used instead.

DEF FN

DEF FN α(α₁, α_k)=e

Result: Defines a function. α and α₁ to α_k can be a single letter or single letter followed by $ for a string argument.

Not on the ZX80.

DIM

DIM α(n₁)  (ZX80)

DIM α(n₁,...,n_k)  (ZX Spectrum)

DIM α$(n₁,...,n_k)  (ZX Spectrum)

Result: Sets up an array of numbers or characters with k dimensions. For numeric arrays all values are set to zero. In the case of a string array all values are set to SPACE (CHR$ 32).

ZX80 arrays are numeric integer, 1-dimensional only and have a base of 0, unlike the ZX81 and ZX Spectrum which have a base of 1, so the code for an array of 10 numbers on the ZX80 would be

DIM A(9)

whereas on the ZX81 and ZX Spectrum it would be

DIM A(10)

String arrays are not allowed on the ZX80.

DRAW

DRAW x,y

DRAW x,y,z

Result: DRAW a high resolution line from the currect PLOT position moving x horizontally and y vertically rotating through angle z if third parameter is specified.

High resolution graphics are not possible on the ZX80.

FLASH

Result: If n is set to 1 flash effect is turned on. If n is set to zero then flash effect is turned off.

As the standard ZX80 is not capable of animated text or graphics it is not possible to recreate the FLASH effect on this micro.

GO SUB

GO SUB n

Result: Stack GO SUB line number and branch (GO TO) line n.

Same on both micros.
The ZX80 keyboard spells GO SUB as 'GOSUB'.
The ZX Spectrum manual is inconsistent with the spelling of GO SUB, using both GO SUB and GOSUB!

GO TO

GO TO n

Result: Branch or GO TO line n.

Again, like above the same on both micros.
The ZX80 keyboard spells GO TO as 'GOTO'.

INK

INK n

Result: Sets foreground colour of chracters to be printed. When n=0 to 7 a colour is selected. When n=8 transparency is selected. When n=9 contrast is selected.

As the ZX80 is a monochrome computer this statement is only available on the Spectrum.

INPUT

INPUT v  (ZX80 & ZX Spectrum)

INPUT v₁,v₂,v₃...  (ZX Spectrum only)

INPUT LINE α$   (ZX Spectrum only)

Result: Computer waits for input of an expression then passes the value of this to the variable v.

The ZX Spectrum command allows for multiple variables to be input on the same INPUT statement i.e. INPUT v₁,v₂,v₃...
ZX Spectrum also allows PRINT items to be used such as INK and PAPER.
INPUT LINE v on the Spectrum strips the quotes on the input line and waits for a string to be input.

INVERSE

INVERSE n

Result: If n=0 characters are printed in normal video. If n=1 characters are printed in inverse video.

The INVERSE statement is not implemented on the ZX80 although inverse characters are available in the ZX80 character set.

LET

LET v=e

Result: Assign the value e to the variable v.

Same on both micros.

LPRINT

LPRINT ...

Result: Send a line of items to be printed to the ZX Printer.

It is not possible to use an unmodified ZX80 with the ZX Printer.

OUT

OUT m,n

Result: Outputs byte n to port m.

Not on the ZX80 but can be accessed from machine code.

OVER

OVER n

Result: If n=0 characters obliterate those already at that position. If n=1 characters are merged with those already at that position.

This is a high resolution display statement and is not available on the ZX80. If n=1 OVER essentially performs an eXclusive OR with the old and new pixels. If both pixels are off (0) they will stay off (0). If the old pixel if off (0) and the new one is on (1) the displayed pixel will be on (1). If both old and new pixels are on (1) the diplayed pixel will be (0).

PAPER

PAPER n

Result: Sets background colour of chracters to be printed. When n=0 to 7 a colour is selected. When n=8 transparency is selected. When n=9 contrast is selected.

As the ZX80 is a monochrome computer this statement is only available on the Spectrum.

PAUSE

PAUSE n

Result: Stop program execution for n*¹/₅₀seconds or until a key is pressed.

On the ZX Spectrum PAUSE 0 is not timed but lasts until a key is pressed.

Not on the ZX80 although a PAUSE can be simulated with a FOR...NEXT loop.

PLOT

Type: Display statement

PLOT c;m,n

Result: Sets pixel ink at position m,n subject to c (INK/PAPER/OVER/INVERSE).

High resolution graphics are not available on the ZX80.

POKE

Type: Memory statement

POKE m,n

Result: Load byte n into memory address m.

Same on both micros.

PRINT

Type: Display statement

PRINT ...

Result: Send a series of items to the display subject to control characters and AT/TAB (and colour/INVERSE/FLASH/OVER on the ZX Spectrum).

Similar on both micros with some exceptions. ZX Spectrum can also PRINT to an I/O device using streams and channels.

RANDOMISE or RANDOMIZE

Type: Numeric statement

RANDOMISE  (ZX80)

RANDOMISE n  (ZX80)

RANDOMIZE  (ZX Spectrum)

RANDOMIZE n  (ZX Spectrum)

Result: Sets system variable SEED to n which will be the basis for pseudo-random numbers (RND).

Same on both micros (except spelling - ZX80 uses the english spelling, ZX Spectrum use the american spelling). ZX80/ZX Spectrum keyboards shows shortened RAND and not RANDOMISE/RANDOMIZE.

READ

Type: Variable assignment statement

READ e₁,e₂,e₃, ...

Result: Read from DATA statement and pass to a variable or variables e₁,e₂,e₃, ..

Not on the ZX80. Dimensional arrays and LET should be used instead.

REM

Type: Programming statement

REM ...

Result: None, display comment in program listing.

Same on both micros. ZX80 micros can utilise REM statements to store machine code and although the ZX Spectrum is also capable of this it is not used as much as it is easier to place machine code above RAMTOP.

RESTORE

Type: Statement used with READ/DATA

RESTORE

RESTORE n

Result: Restores DATA pointer to line n or first line of program if n is not specified. READ will starting reading from there.

Not on the ZX80. Dimensional arrays and LET should be used instead.

RETURN

Type: Branching statement

RETURN

Result: Take line number off GO SUB stack and GO TO the line after that line number.

Same on both micros.

STOP

Type: Program execution statement

STOP

Result: Stops program execution with Report 9.

Same on both micros.

TAB

Type: Display statement

TAB x

Result: Changes PRINT, LPRINT or INPUT tab position to x.

Not on the ZX80 although automatic tabs (, comma) 8 characters across could be used.

See also comma (PRINT delimiter).

Routine to produce TABs on the ZX80

Compound Statements & Structured Statements

Keyword

Meaning

Comments

FOR...NEXT loop

(FOR, TO, NEXT)
ZX80

(FOR, TO, [STEP,] NEXT)
ZX Spectrum

Type: Loop statements/Variable assignment statement

FOR α=x TO y  (ZX80)

    [section of program to be repeated goes here]

NEXT α

FOR α=x TO y STEP z  (ZX Spectrum)

    [section of program to be repeated goes here]

NEXT α

Result: Sets up and executes the loop α from x to y with a step of z.

[Note] Step of +1 assumed if STEP omitted)

Same on both micros except that the ZX80 has no STEP parameter.

Although the NEXT statement is not compounded within the FOR statement as TO and STEP are, it is included here for completeness.

Routine to simulate STEP on the ZX80

IF..THEN

Type: Conditional statements

IF x THEN s

Result: If x is true (non-zero) then s will be executed.

Same on both micros.

Functions

Keyword

Meaning

Comments

ABS

Type: Mathematical function

ABS(x) (ZX80)

ABS x (ZX Spectrum)

Returns: Absolute magnitude of x, i.e. distance on number line from zero, -1=1 -2=2

Same on both micros.

On the ZX80 ABS is an integral function.

ACS

Type: Trigonometric function

ACS x

Returns: Arccosine (inverse cosine) of x in radians.

Trigonometric functions are not available on the ZX80.

ASN

Type: Trigonometric function

ASN x

Returns: Arcsine (inverse sine) of x in radians.

Trigonometric functions are not available on the ZX80.

ATN

Type: Trigonometric function

ATN x

Returns: Arctangent (inverse tangent) of x in radians.

Trigonometric functions are not available on the ZX80.

ATTR

Type: Display function

ATTR (x,y)

Returns: numeric value between 0 and 255 of the attribute at position x,y.

As the ZX80 is a monochrome computer this function is only available on the Spectrum.

BIN

Type: Numeric notation

BIN b

Returns: decimal value of a base₂ (binary) 16 bit number.

Only on Spectrum.

A short routine for the ZX80 to take a string of binary digits and convert them to decimal.

CHR$

Type: String function

CHR$(x) (ZX80)

CHR$ x (ZX Spectrum)

Returns: Single character from position x in the character set.

Although the CHR$ function performs the same task on both computers the end result will be different as the Spectrum's character set is based on the ASCII code, while the ZX80's is unique.

On the ZX80 CHR$ is an integral function.

CODE

Type: String function

CODE(α$) (ZX80)

CODE α$ (ZX Spectrum)

Returns: Numeric value (between 0 and 255) representing the position in the character set of α$.
This is the inverse of the CHR$ function.

Although the CODE function performs the same task on both computers, just like CHR$ above, the end result will also be different.

On the ZX80 CODE is an integral function.

COS

Type: Trigonometric function

COS x

Returns: Cosine of x in radians.

Trigonometric functions are not available on the ZX80.

EXP

Type: Mathematical function

EXP x

Returns: Numeric value for the function e^x where e=2.7182818...

Not on the ZX80.

FN

Type: User defined function

FN α(α₁, α_k)

Result: Calls a function. α and α₁ to α_k can be a single letter or single letter followed by $ for a string argument.

Not on the ZX80.

See also DEF FN.

INKEY$

Type: String function

INKEY$ has no operands.

Returns: Single character from a keypress.

Typical usage would be

PRINT INKEY$

LET A$=INKEY$ or

10 IF INKEY$="" THEN GO TO 10

Not on the ZX80.

IN

Type: Numeric function

IN m

Returns: numeric value between 0 and 255 for the port m.

Not on the ZX80 but can be accessed from machine code.

INT

Type: Mathematical function

INT x

Returns: x rounded down to the nearest integer.

Not required on the ZX80 as this micro is integer based anyway.

When converting programs from the ZX80 to the ZX Spectrum INT should be placed in front of any division operator, for example:

PRINT 7/5

would yield 1 on the ZX80 but 1.4 on the ZX Spectrum. We must use the following code to give the correct result on the Spectrum.

PRINT INT(7/5)

[Note] On the ZX Spectrum when INT -65536 is performed the wrong result is given as -1.

LEN

Type: String function

LEN α$

Returns: numeric value for the length of α$.

Not available on the ZX80..

Routine to simulate LEN on the ZX80

LN

Type: Mathematical function

LN x

Returns: numeric value for the natural logarithm of x.

Not on the ZX80.

PEEK

Type: Memory function

PEEK(m) (ZX80)

PEEK m (ZX Spectrum)

Returns: numeric value (0 to 255) stored at memory location m.

Same on both micros.

On the ZX80 PEEK is an integral function.

PI

Type: Constant

PI has no operands.

Returns: 3.1415927 (π) Ratio of circumference of a circle to its diameter

Typical usage might be:

LET R=C/(2*PI)

Not on the ZX80

[Note] PI is stored on the ZX Spectrum as 10 digits but will only display 8 digits.

POINT

Type: Display function

POINT (x,y)

Returns: 0 or 1 for the screen location x,y.

This is a high resolution function and is not available on the ZX80.

RND

Type: Mathematical function

RND(n)  (ZX80)

RND  (ZX Spectrum)

Returns  (ZX80)

A pseudo-random number in the range:
1 to n if n>0
1 to 32767 or -32768 to n-1 if n<0.
1 if n=0

Returns  (ZX Spectrum)

A pseudo-random number between 0 and 1 is generated, no operands are required.

An example of usage would be

LET X=RND(42)  (ZX80)

LET X=INT(RND*42)+1  (ZX Spectrum)

Although both micros both produce a pseudo-random number the ZX80 with generate an integer between -32768 and 32767 and the ZX Spectrum will generate a decimal fraction between 0 and 1.

SCREEN$

Type: Display function

SCREEN$ (x,y)

Returns: character displayed at location x,y.

Not on the ZX80.

SGN

Type: Mathematical function

SGN x

Returns: signum (or sign) of x, for instance -1 if x<0, 0 if x=0 or 1 if x>1.

Not on the ZX80 but can be simulated with the following code:

LET S=(-1 AND X<0)+(1 AND X>0)

where X is a number and S is the signum result.

Routine to simulate SGN on the ZX80

SQR

Type: Mathematical function

SQR x

Returns: square root of x.

Not on the ZX80.

Routine to produce a square root (SQR) on the ZX80.

STR$

Type: String function

STR$(x) (ZX80)

STR$ x (ZX Spectrum)

Result: string comprising of the numeric value of x.

Same for both micros.

On the ZX80 STR$ is an integral function.

TAN

Type: Trigonometric function

TAN x

Returns: Tangent of x in radians.

Trigonometric functions are not available on the ZX80.

TL$

Type: String function

TL$(α$)

Returns: α$ less its first character.

Exclusive to the ZX80 but is easily implemented on the ZX Spectrum or ZX81 with:

α$(2 TO)

On the ZX80 TL$ is an integral function.

USR

Type: System function

USR(x) (ZX80)

USR x (ZX Spectrum)

Returns: contents of the hl register pair (ZX80) or bc register pair (ZX Spectrum) after calling machine code at memory location x.

Same for both micros except the different register pairs returned.

On the ZX80 USR is an integral function.

USR

Type: Memory function

USR α$

Returns: location in memory of user defined graphic α$.

The function USR (with string argument) is completely different to USR (numeric argument) above and is used to find the location of a particular user-defined graphic. Since the ZX80 has no UDG's this function is not available on the ZX80.

VAL

Type: String function

VAL α$

Returns: numeric value evaluated from the string α$.

Not on the ZX80.

Routine to simulate VAL on the ZX80.

VAL$

Type: String function

VAL$ α$

Returns: string evaluated from the string α$.

There does not appear to be a simple way to simulate this function in ZX80 BASIC.

Operators

Keyword

Meaning

Comments

-

Unary Minus/Negation

Type: Mathematical operator

-x

Result: negates x

Same on both micros.

-

Binary Minus/Subtraction

Type: Mathematical operator

x-y

Result: a numeric value resulting from y being subtracted from x.

Same on both micros.

+

Addition

Type: Mathematical operator

x+y

Result: a numeric value resulting from y being added to x.

Same on both micros.

+

String concatenation

Type: String operator

α$+β$

Result: concatenates (joins together) string α with string β to form a new string.

String concatenation is not possible on the ZX80.

/

Division

Type: Mathematical operator

x/y

Result: a numeric value resulting from x being divided by y.

On the ZX80 this is always integer division.

See also INT.

*

Multiplication

Type: Mathematical operator

x*y

Result: a numeric value resulting from x being multiplied by y.

Same on both micros.

** or ↑

Raise to the power of

Type: Mathematical operator

x**y (ZX80)

x↑y (ZX Spectrum)

Result: a numeric value resulting from x being raised to the power of y.

Same meaning on both micros but the ZX80 uses a double asterisk ** whereas the ZX Spectrum uses an up arrow ↑.

If y is negative on the ZX80 error 6 (arithmetic overflow) will occur.

<

Less than

Type: Comparison operator

x<y

Where x and y can be either numeric or strings but cannot be mixed.

Result: -1 if x<y otherwise 0. (ZX80)

Result: 1 if x<y otherwise 0. (ZX Spectrum)

A true result on the ZX80 will give -1. Placing ABS around the equation like so

ABS(x<y)

will make the result +1 like the ZX Spectrum.

Conversely, on the Spectrum multiply the result by -1 to give the same result as the ZX80:

-1*(x<y)

>

Greater than

Type: Comparison operator

x>y

Where x and y can be either numeric or strings but cannot be mixed.

Result: -1 if x>y otherwise 0. (ZX80)

Result: 1 if x>y otherwise 0. (ZX Spectrum)

A true result on the ZX80 will give -1. Placing ABS around the equation like so

ABS(x>y)

will make the result +1 like the ZX Spectrum.

Conversely, on the Spectrum multiply the result by -1 to give the same result as the ZX80:

-1*(x>y)

<=

Less than or equal to

Type: Comparison operator

x<=y

Where x and y can be either numeric or strings but cannot be mixed.

Result: 1 if x≤y otherwise 0.

Not on the ZX80.

Use the following code instead:

NOT (x>y)

Result will be -1 if true.

>=

Greater than or equal to

Type: Comparison operator

x>=y

Where x and y can be either numeric or strings but cannot be mixed.

Result: 1 if x≥y otherwise 0.

Not on the ZX80.

Use the following code instead:

NOT (x<y)

Result will be -1 if true.

=

Is equal to

Type: Comparison operator

x=y

Where x and y can be either numeric or strings but cannot be mixed.

Result: -1 if x=y otherwise 0. (ZX80)

Result: 1 if x=y otherwise 0. (ZX Spectrum)

A true result on the ZX80 will give -1. Placing ABS around the equation like so

ABS(x=y)

will make the result +1 like the ZX Spectrum.

Conversely, on the Spectrum multiply the result by -1 to give the same result as the ZX80:

-1*(x=y)

<>

Is not equal to

Type: Comparison operator

x<>y

Where x and y can be either numeric or strings but cannot be mixed.

Result: 1 if x≠y otherwise 0.

Not on the ZX80.

Use the following code instead:

NOT (x=y)

Result will be -1 if true.

AND

Type: Logical operator

x AND y

Where x and y are always numeric. (ZX80)

Where x is a number or a string, and y is always numeric. (ZX Spectrum)

Returns: x if y is true (non-zero) or 0 if y is false (zero).

Strings cannot be tested directly with AND on the ZX80.

OR

Type: Logical operator

x OR y

Returns: 1 if x or y≠0, value of x if b=0.

Same on both micros

NOT

Type: Logical operator

NOT x

Returns: zero if x≠0, 1 if x=0

Same on both

TO

Type: String operator

v$(x TO y)

v$(x TO)

v$(TO y)

v$( TO ) * This works but is pointless!

Returns: Slices string v from x to y, x to end of string or start of string to y. TO without any operands will return a string unsliced (see fourth example).

Apart from TL$ the ZX80 has no string slicing capabilities.

Routine to simulate v(x TO) on the ZX80

Delimiters

Keyword

Meaning

Comments

;

Semi-colon

Type: PRINT delimiter

PRINT ;  (ZX80 & ZX Spectrum)

LPRINT ;  (ZX Spectrum)

INPUT ;  (ZX Spectrum)

Result: separates items within a PRINT, LPRINT (ZX Spectrum only) or INPUT (ZX Spectrum only) statement.

ZX80 cannot use a semi-colon as a delimiter with an INPUT statement.

'

Apostrophe

Type: PRINT delimiter

PRINT '  (ZX80 & ZX Spectrum)

LPRINT '  (ZX Spectrum)

INPUT '  (ZX Spectrum)

Result: Moves the PRINT or LPRINT position down a line.

ZX80 cannot use an apostrophe as a delimiter in an INPUT statement.

,

Comma

Type: PRINT delimiter

PRINT ,  (ZX80 & ZX Spectrum)

LPRINT ,  (ZX Spectrum)

INPUT ,  (ZX Spectrum)

Result: Moves the PRINT position across the screen (or printer) or to the start of the next line if PRINT position is greater or equal to the last tab position.

ZX80 cannot use a comma as a delimiter in an INPUT statement.

Automatic tabs are 8 characters across on the ZX80 and 16 on the ZX Spectrum or ZX Printer.

,

Comma

Type: Operand delimiter

Separates operands within a statement.

Examples:

POKE x,y (ZX80 & ZX Spectrum)

ATTR (x,y) (ZX Spectrum)

Result: Separates operands within a statement.

ZX80 cannot use a comma as a delimiter in an INPUT statement.

#

Hash

Type: Stream escape

PRINT #m

LPRINT #m

INPUT #m

Result: Output to stream m.

Only on the ZX Spectrum.

:

Colon

Type: Statement delimiter

s₁ : s₂ : s₃ ...

Result: Allows more than one statement per line number to be entered.

Only on the ZX Spectrum.

"

Single quotation marks

Type: String encloser

α$="Ford Prefect"  (ZX80 & ZX Spectrum)

PRINT "Ford Prefect"  (ZX80 & ZX Spectrum)

LPRINT "Ford Prefect"  (ZX Spectrum)

INPUT "Ford Prefect"  (ZX Spectrum)

Result: Encloses text within a string.
Encloses text with a PRINT, LPRINT or INPUT (ZX Spectrum only) statement.

ZX80 cannot use a single quotes within an INPUT statement.

ZX Spectrum can store a single quote within a set of quotation marks like so

""""

The ZX80 cannot place a quote within a string. If there was some way of adding a character to a string then it may be possible to use

CHR$(212)

212 is the ZX80 code for a single quote.

The ZX80 can use this in a PRINT statement though:

PRINT CHR$(212);"DOLPHIN";CHR$(212)

Will produce:"DOLPHIN"

Nomenclature

This list uses the same letters to represent variables, expressions and sequences etc. as the ZX80 and ZX Spectrum BASIC manuals.

α,β represents a single letter
v represents a variable
x,y,z represents numerical expressions
m,n represents numerical expressions rounded to the nearest integer
b represents a 16 bit binary number
e represents an expression
f represents a string valued expression
s represents a sequence of statement separated by colons :
c represents a sequence of colour items, each terminated by commas , or semi-colons ; A color item has the form of a PAPER, INK, FLASH, BRIGHT, INVERSE or OVER statement.

A note on brackets. Where brackets are shown they are mandatory, this includes the ZX80 integral functions and ZX Spectrum 'two parameter' functions and user defined functions.

References

A Course in BASIC Programming - ZX80 Operating Manual, Science of Cambridge / Sinclair (publisher)
Sinclair ZX Spectrum BASIC Programming, Steven Vickers (author), Robin Bradbeer (editor)

External Links

ZX80 Operating Manual in PDF Format at hackaday.io
ZX Spectrum manual for download at retro 8-bit computers

Last revision : 22/02/2023

A Comparision of Keywords on the ZX80 and ZX Spectrum

Overview

Commands

Keyword

Meaning

Comments

CLEAR

CONTINUE

LIST

LLIST

LOAD

MERGE

NEW

RUN

SAVE

VERIFY

Statements

Keyword

Meaning

Comments

AT

BEEP

BORDER

BRIGHT

CIRCLE

CLS

COPY

DATA

DEF FN

DIM

DRAW

FLASH

GO SUB

GO TO

INK

INPUT

INVERSE

LET

LPRINT

OUT

OVER

PAPER

PAUSE

PLOT

POKE

PRINT

RANDOMISE or RANDOMIZE

READ

REM

RESTORE

RETURN

STOP

TAB

Compound Statements & Structured Statements

Keyword

Meaning

Comments

FOR...NEXT loop

(FOR, TO, NEXT)ZX80

(FOR, TO, [STEP,] NEXT)ZX Spectrum

IF..THEN

Functions

Keyword

Meaning

Comments

ABS

ACS

ASN

ATN

ATTR

BIN

CHR$

CODE

COS

EXP

FN

INKEY$

IN

INT

LEN

(FOR, TO, NEXT)
ZX80

(FOR, TO, [STEP,] NEXT)
ZX Spectrum