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EhBASIC language reference

Enhanced BASIC language reference An advanced BASIC interpreter for the 6502 microprocessor.”
Numbers
Numbers may range from zero to plus or minus 1.70141173×10^38 and will have an
accuracy of just under 1 part in 1.68 x 10^7.
Numbers can be preceded by a sign, + or -, and are written as a string of
numeric digits with or without a decimal point and can also have a positive
or negative exponent as a power of 10 multiplier e.g.

-142 96.3 0.25 -136.42E-3 -1.3E7 1

.. are all valid numbers.
Integer numbers, i.e. with no decimal fraction or exponent, can also be in
either hexadecimal or binary. Hexadecimal numbers should be preceded by $
and binary numbers preceded by %, e.g.

%101010 -$FFE0 $A0127BD -%10011001 %00001010 $0A

.. again are all valid numbers.
Strings
Strings are any string of printable characters enclosed in a pair of quotation marks.
Non printing characters may be converted to single character strings using the
CHR$() functions.

“Hello world” “-136.42E-3” “+—-+—-+” “[Y/n]” “Y”

Are all valid strings.
Variables
Variables of both numeric and string type are available. String variables are
distinguished by the $ suffix. As well as simple variables arrays are also
available and these may be either numeric or string and are distinguished by their
bracketed indicies after the variable name.
Variable names may be any length but only the first two name characters are significant
so BL and BLANK will refer to the same variable. The first character must be one of “A”
to “Z” or “a” to “z”, following characters may also include numbers. E.g.

A A$ NAME$ x2LIM y colour s1 s2

Variable names are case sensitive so AB, Ab, aB and ab are all separate variables.
Variable names may not contain BASIC keywords. Keywords are only valid in upper
case so ‘PRINTER’ is not allowed (it would be interpreted as PRINT ER) but ‘printer’
is.
Note that spaces in variable names are ignored so ‘print e r’, ‘print er’ and ‘pri nter’
will all be interpreted the same way.
BASIC Keywords
Here is a list of BASIC keywords. They are only valid when entered in upper case as
shown and spaces may not be included in them. So GOTO is valid BASIC keyword but GO TO
is not.

ABS AND ASC ATN BIN$ BITCLR BITSET
BITTST CALL CHR$ CLEAR CONT COS DATA
DEC DEEK DEF DIM DO DOKE END
EOR EXP FN FOR FRE GET GOSUB
GOTO HEX$ IF INC INPUT INT IRQ
LCASE$ LEFT$ LEN LET LIST LOAD LOG
LOOP MAX MID$ MIN NEW NEXT NMI
NOT NULL OFF ON OR PEEK PI
POKE POS PRINT READ REM RESTORE RETIRQ
RETNMI RETURN RIGHT$ RND RUN SADD SAVE
SIN SGN SPC( SQR STEP STOP STR$
SWAP TAB( TAN THEN TO TWOPI UCASE$
UNTIL USR VAL VARPTR WAIT WHILE WIDTH
+ * / ^ << >>
> = <
  • Anything in upper case is part of the command/function structure and must be present
  • Anything in lower case enclosed in < > is to be supplied by the user
  • Anything enclosed in [ ] is optional
  • Anything enclosed in { } and separated by | characters are multi choice options
  • Any items followed by an ellipsis, … , may be repeated any number of times
  • Any punctuation and symbols, except those above, are part of the structure and must be included
var is a valid variable name
var$ is a valid string variable name
var() is a valid array name
var$() is a valid string array name
expression is any expression returning a result
expression$ is any expression returning a string result
addr is an integer in the range +/- 16777215 that will be wrapped to the range 0 to 65535
b is a byte value 0 to 255
n is an integer in the range 0 to 63999
w is an integer in the range -32768 to 32767
i is a +ve integer value
r is real number
+r is a +ve value real number (0 is considered +ve)
$ is a string literal

BASIC Commands

END
Terminates program execution and returns control to the command line (direct mode).
END may be placed anywhere in a program, it does not have to be on the last line, and
there may be any number, including none, of ENDs in total.
Note. CONT may be used after and END to resume execution from the next statement.

FOR <var> = <expression> TO <expression> [STEP expression]
Assigns a variable to a loop counter and optionally sets the start value, the end
value and the step size. If STEP expression is omitted then a default step size of
+1 will be assumed.

NEXT [var[,var]…]
Increments or decrements a loop variable and checks for the terminating condition. If
the terminating condition has been reached then execution continues with the next
command, else execution continues with the command after the FOR assignment. See FOR.

DATA [{r|$}[,{r|$}]…]
Defines a constant or series of constants. Real constants are held as
strings in program memory and can be read as numeric values or string
values. String constants may contain spaces but if they need to contain
commas then they must be enclosed in quotes.

INPUT [“$”;] <var>[,var]…
Get a variable, or list of variables from the input stream. A question mark, “?”, is
always output, after the string if there is one, and if further input is required,
i.e. there are more variables in the list than the user entered values, then a double
question mark, “??”, will be output until enough values have been entered.
There are two possible messages that may appear during the execution of an input
statement:
Extra ignored
The user has attempted to enter more values than are required. Program
execution will continue but the extraneous data entered has been discarded.
Redo from start
The user has attempted to enter a string where a number was expected. The
reverse never causes an error as numbers are also valid strings.

DIM <var[$](i1[,i2[,in]…])>[,var[$](i1[,i2[,in]…])]…
Dimension arrays. Creates arrays of either string or numeric variables. The arrays
can have one or more dimensions. The lower limit of any dimension is always
zero and the upper limit is i. If you do not explicitly dimension an array then
it’s number of dimensions will be set when you first access it and the
upper bound will be set to 10 for each dimension.

READ <var>[,var]…
Reads values from DATA statements and assigns them to variables. Trying to
read a string literal into a numeric variable will cause a syntax error.

LET <var> = <expression>
Assign the value of expression to var. Both var and expression bust be of the
same type. The LET command word is optional and just <var> = <expression> will
give exactly the same result. It is only maintained for historical reasons.

DEC <var>[,var]…
Decrement variables. The variables listed will have their values decremented
by one. Trying to decrement a string variable will give a type mismatch error.
DEC A is much faster than doing A=A-1 and DEC A,A is slightly faster than
doing A=A-2.

SWAP <var[$]>,<var[$]>
Swap two variables. The variables listed will have their values exchanged. Both
must be of the same type, numeric or string, and either, or both, may be array
elements. Trying to swap a numeric and string variable will give a type mismatch
error.

GOTO <n>
Continue execution from line number n

RUN [n]
Begins execution of the program currently in memory at the lowest numbered line.
RUN erases all variables and functions, resets FOR .. NEXT, GOSUB .. RETURN and
DO ..LOOP states and sets the data pointer to the program start.

If n is specified then programme execution will start at the specified line number.

IF <expression>[relation expression] THEN<{{statement|n}|{GOTO|GOSUB}n}>
Evaluates expression. If the result of expression is non zero then the statement(s)
after the THEN or the GOTO or GOSUB are executed. If the result of expression is
zero then execution continues with the next line.

RESTORE [n]
Reset the DATA pointer. If n is specified then the pointer will be reset to the
beginning of line n else it will be reset to the start of the program. If n is
specified but doesn’t exist an error will be generated.

GOSUB <n>
Call a subroutine at line n. Program execution is diverted to line n but the
calling point is remembered. Upon encountering a RETURN statement program
execution will continue with the next statement (line) after the GOSUB.

RETIRQ
Returns program execution to the next statement after an interrupt, automatically
restores the IRQ enabled flag. See ON IRQ.

RETNMI
Returns program execution to the next statement after an interrupt, automatically
restores the NMI enabled flag. See ON NMI.

RETURN
Returns program execution to the next statement (line) after the last GOSUB
encountered. See GOSUB. Also returns program execution to the next statement
after an interrupt but does not restore the enabled flags.

REM
Everything following this statement on this program line will be ignored,
even colons.

STOP
Halts program execution and generates a “Break in line n” message where n is the
line in which the STOP was encountered.

OFF
See IRQ or NMI.

ON <expression> {GOTO|GOSUB} <n>[,n]…
The integer value of expression is calculated and then the nth number after the
GOTO or GOSUB is taken (where n is the result of expression). Note that valid
results for expression range only from zero to 255. Any result outside this
range will cause a Function call error.

ON {IRQ|NMI} <n>
Set up the IRQ or NMI routine pointers. This sets up the effective GOSUB line
that is taken when an interrupt happens. When the effective GOSUB is taken the
interrupt, IRQ or NMI, is turned off. This can be turned back on with the interrupt
on command or by using the matching special return. The normal program flow is
resumed by any of RETIRQ, RETNMI or RETURN.

NULL <n>
Sets the number of null characters printed by BASIC after every carriage
return. n may be specified in the range 0 to 255.

INC <var>[,var]…
Increment variables. The variables listed will have their values incremented
by one. Trying to increment a string variable will give a type mismatch error.
INC A is much faster than doing A=A+1 and INC A,A is slightly faster than
doing A=A+2.

WAIT <addr,b1>[,b2]
Program execution will wait at this point until the value of the location addr
exclusive ORed with b2 then ANDed with b1 is non zero. If b2 is not defined then
it is assumed to be zero. Note b1 and b2 must both be byte values.

LOAD
Does nothing in this version but does it via a vector in RAM so is easily patched.

SAVE
Does nothing in this version but does it via a vector in RAM so is easily patched.

DEF FN <name>(<var>) = <statement>
Defines <statement> as function <name>. <name> can be any valid numeric variable
name of one or more characters. <var> must be a simple variable and is used to
pass a numeric argument into the function.
Note that the value of <var> will be unchanged if it is used in the function
so <var> should be considered to be a local variable name.

POKE <addr,b>
Writes the byte value b into the address addr.

DOKE <addr,w>
Writes the word value w into the addresses addr and addr+1, the lower byte of
w is in addr. Note if addr = 65535 ($FFFF) then the high byte will be written
to address zero.

CALL <addr>
CALLs a user subroutine at address addr. No values are passed or returned and
so this is much faster than using USR()

DO
Marks the beginning of a DO .. LOOP loop (See LOOP). No parameters. This
command can be nested like FOR .. NEXT or GOSUB .. RETURN.

LOOP [{UNTIL|WHILE} expression]
Marks the end of a DO .. LOOP loop. There are three possible variations on the
LOOP command ..
LOOP
This loop repeats forever. With just this command control is passed back to the
next command after the corresponding DO.
LOOP UNTIL expression
This loop will repeat until the value of expression is non zero. Once that
occurs execution will continue with the next command after the LOOP UNTIL.
LOOP WHILE expression
This loop will repeat while the value of expression is non zero. When the
value of expression is zero execution will continue with the next command
after the LOOP WHILE.

PRINT [expression][{;|,}expression]…[{;|,}]
Outputs the value of each expressions. If the list of expressions to be output
does not end with a comma or a semi-colon, then a carriage return and linefeed
is output after the values.
Expressions on the line can be separated with either a semi-colon, causing the
next expression to follow immediately, or a comma which will advance the output
to the next tab stop before continuing to print. If there are no expressions and
no comma or semi-colon after the PRINT statement then a carriage return and
linefeed is output.
When entering a program line, or immediate statement, PRINT can be abbreviated to ?

CONT
Continues program execution after CTRL-C has been typed, a STOP has been encountered
during program execution or a null input was given to an INPUT request.

LIST [n1][-n2]
Lists the entire program held in memory. If n1 is specified then the listing will
start from line n1 and run to the end of the program. If -n2 is specified then the
listing will terminate after line n2 has been listed. If n1 and -n2 are specified
then all the lines from n1 to n2 inclusive will be listed.
Note. If n1 does not exist then the list will start from the next line numbered
after n1. If n2 does not exist then the listing will stop with the last line
numbered before n2.
Also note. LIST can be executed from within a program, first a [CR][LF] is printed
and then the specified lines, if any, each terminated with another [CR][LF].
Program execution then continues as normal.

CLEAR
Erases all variables and functions and resets FOR .. NEXT, GOSUB .. RETURN and
DO ..LOOP states.

NEW
Deletes the current program and all variables from memory.

WIDTH {b1|,b2|b1,b2}
Sets the terminal width and TAB spacing. b1 is the terminal width and b2 is the tab
spacing, default is 80 and 14. Width can be zero, for “infinite” terminal width, or
from 16 to 255. The tab size is from 2 to width-1 or 127, whichever is smaller.

GET <var[$]>
Gets a key, if there is one, from the input device. If there is no key waiting then
var will be set to 0 and var$ will return a null string “”. GET does not halt and
execution will continue.

IRQ {ON|OFF|CLEAR}
Enables or disables the IRQ handling subroutine. Note that turning the handler off
does not suppress the interrupt detection and if an interrupt occurs while handling is
off it will be actioned as soon as handling is turned back on. Using CLEAR clears the
interrupt assignment and it can only be restarted with an ON IRQ command

NMI {ON|OFF|CLEAR}
Enables or disables the NMI handling subroutine. Note that turning the handler off
does not suppress the interrupt detection and if an interrupt occurs while handling is
off it will be actioned as soon as handling is turned back on. Using CLEAR clears the
interrupt assignment and it can only be restarted with an ON NMI command

TAB(<expression>)
Sets the cursor position to <expression>. If the cursor is already beyond that
point then the cursor will be left where it is. This command is only valid in a
PRINT statement.

TO
Sets the range in a FOR .. NEXT loop. See FOR.

FN<name>(<expression>)
See DEF.

SPC(<expression>)
Prints <expression> spaces. This command is only valid in a PRINT statement.

THEN
See IF.

NOT <expression>
Generates the bitwise NOT of then signed integer value of <expression>.

STEP
Sets the step size in a FOR .. NEXT loop. See FOR.

UNTIL
See DO and LOOP.

WHILE
See DO and LOOP.

BITCLR <addr>,<b>
Clears bit b of address addr. Valid bit numbers are 0, the least significant bit, to
7, the most significant bit. Values outside this range will cause a function call
error.

BITSET <addr>,<b>
Sets bit b of address addr. Valid bit numbers are 0, the least significant
bit, to 7, the most significant bit. Values outside this range will cause a
function call error.
BASIC Operators
Operators perform mathematical or logical operations on values and return the result.
The operation is usually preceded by a variable name and equality sign or is part of
an IF .. THEN statement.

+ Add. c = a + b will assign the sum of a and b to c.
Subtract. c = a – b will assign the result of a minus b to c.
* Multiply. c = a * b will assign the product of a and b to c.
/ Divide. c = a / b will assign the result of a divided by b to c.
^ Raise to the power of. c = a ^ b will assign the result of a raised to the power of b to c.
AND Logical AND. c = a AND b will assign the logical AND of a and b to c
EOR Logical Exclusive OR. c = a EOR b will assign the logical exclusive OR of a and b to c.
OR Logical OR. c = a OR b will assign the logical inclusive OR of a and b to c.
<< Shift left. c = a << b will assign the result of a shifted left by b bits to c.
>> Shift right. c = a >> b will assign the result of a shifted right by b bits to c.
= Equals. c = a = b will assign the result of the comparison a = b to c.
> Greater than. c = a < b will assign the result of the comparison a > b to c.
< Less than. c = a < b will assign the result of the comparison of a < b to c.

The three comparison operators can be mixed to provide further operators ..

>= or => Greater than or equal to.
<= or =< Less than or equal to.
<> or >< Not equal to (greater than or less than).
<=> any order Always true (greater than or equal to or less than).

BASIC Functions
Functions always return a value, be it numeric or string, so are used on the right hand
side of the = sign in assignments, on either side of operators and in commands requiring
an expression e.g. after PRINT, within expressions, or in other functions.

SGN(<expression>)
Returns the sign of <expression>. If the value is +ve SGN returns +1, if
the value is -ve then SGN returns -1. If expression=0 then SGN returns 0.

INT(<expression>)
Returns the integer of <expression>.

ABS(<expression>)
Returns the absolute value of <expression>.

USR(<expression>)
Takes the value of <expression> and places it in FAC1 and then calls the
USeR routine pointed to by the vector at $0B,$0C. What the routine does
with this value is entirely up to the user, it can even be safely ignored
if it isn’t needed. The routine, after the user code has done an RTS, takes
whatever is in FAC1 and returns that. Note it can be either a numeric or
string value.
If no value needs to be passed or returned then CALL is a better option.

FRE(<expression>)
Returns the amount of free program memory. The value of expression is ignored
and can be numeric or string.

POS(<expression>)
Returns the POSition of the cursor on the terminal line. The value of expression
is ignored.

SQR(<expression>)
Returns the square root of <expression>.

RND(<expression>)
Returns a random number in the range 0 to 1. If the value of <expression> is
non zero then it will be used as the seed for the returned pseudo random number
otherwise the next number in the sequence will be returned.

LOG(<expression>)
Returns the natural logarithm (base e) of <expression>.

EXP(<expression>)
Returns e^<expression>. Natural antilog.

COS(<expression>)
Returns the cosine of the angle <expression> radians.

SIN(<expression>)
Returns the sine of the angle <expression> radians.

TAN(<expression>)
Returns the tangent of the angle <expression> radians.

ATN(<expression>)
Returns, in radians, the arctangent of <expression>.

PEEK(<addr>)
Returns the byte value of <addr>.

DEEK(<addr>)
Returns the word value of <addr> and addr+1 as an integer in the range -32768
to 32767. Addr holds the word low byte.

SADD(<{var$|var$()}>)
Returns the address of var$ or var$(). This returns a pointer to the actual string
in memory not the descriptor. If you want the pointer to the descriptor use
VARPTR instead.

LEN(<expression$>)
Returns the length of <expression$>.

STR$(<expression>)
Returns the result of <expression> as a string.

VAL(<expression$>)
Returns the value of <expression$>.

ASC(<expression$>)
Returns the ASCII value of the first character of <expression$>.

LCASE$(<expression$>)
Returns <expression$> with all the alpha characters in lower case.

UCASE$(<expression$>)
Returns <expression$> with all the alpha characters in upper case.

CHR$(b)
Returns single character string of character <b>.

HEX$(<expression>[,b])
Returns <expression> as a hex string. If b is omitted, or if b = 0, then
the string is returned with all leading zeroes removed and is of variable length.
If b is set, permissible values range from 1 to 6, then a string of length b will
be returned. The result is always unsigned and calling this function with expression
> 2^24-1 or b > 6 will cause a function call error.

BIN$(<expression>[,b])
Returns <expression> as a binary string. If b is omitted, or if b = 0, then
the string is returned with all leading zeroes removed and is of variable length.
If b is set, permissible values range from 1 to 24, then a string of length b will
be returned. The result is always unsigned and calling this function with expression
> 2^24-1 or b > 24 will cause a function call error.

BITTST(<addr>,<b>)
Tests bit b of address addr. Valid bit numbers are 0, the least significant bit, to 7,
the most significant bit. Values outside this range will cause a function call error.
Returns zero if the bit was zero, returns -1 if the bit was 1.

MAX(<expression>[,<expression>]…)
Returns the maximum value from a list of numeric expressions. There must be
at least one expression but the upper limit is dictated by the line length.
Each expression is evaluated in turn and the largest of them returned.

MIN(<expression>[,<expression>]…)
Returns the minimum value from a list of numeric expressions. There must be
at least one expression but the upper limit is dictated by the line length.
Each expression is evaluated in turn and the smallest of them returned.

PI
Returns the value of pi as 3.14159274 (closest floating value).

TWOPI
Returns the value of 2*pi as 6.28318548 (closest floating value).

VARPTR(<var[$]>)
Returns a pointer to the variable memory space. If the variable is numeric, or a
numeric array element, then VARPTR returns the pointer to the packed value of that
variable in memory. If the variable is a string, or a string array element, then
VARPTR returns a pointer to the descriptor for that string. If you want the pointer
to the string itself use SADD instead.

LEFT$(<expression$,b>)
Returns the leftmost b characters of <expression$>.

RIGHT$(<expression$,b>)
Returns the rightmost b characters of <expression$>.

MID$(<expression$,b1>[,b2])
Returns the substring string from character b1 of expression$ of length b2. The
characters of expression$ are numbered from 1 starting with the leftmost. If b2 is
omitted then all the characters from b1 to the end of the string are returned.
BASIC Error Messages
These all occur from time to time and, if the error occurred while executing a program,
will be followed by “in line ” where is the number of the line in which the error
occurred.
NEXT without FOR Error
NEXT has been encountered and no matching FOR could be found.
Syntax Error
Just generally wrong. 8^)=
RETURN without GOSUB Error
RETURN has been encountered and no matching GOSUB could be found.
Out of DATA Error
A READ has tried to read data beyond the last item. Usually because you either
mistyped the DATA lines, miscounted the DATA, RESTOREd to the wrong place or
just plain forgot to restore.
Function call Error
Some parameter of a function was outside it’s limits. E.g. Trying to POKE a
value of less than 0 or greater than 255.
Overflow Error
The result of a calculation has exceeded the numerical range of BASIC. This is
plus or minus 1.7014117+E38
Out of memory Error
Anything that uses memory can cause this but mostly it’s writing and running
programmes that does it.
Undefined statement Error
Either a GOTO, GOSUB, RUN or RESTORE was attempted to a line that doesn’t exist
or the line referred to in an ON <expression> {GOTO|GOSUB} or ON {IRQ|NMI}
doesn’t exist.
Array bounds Error
An attempt was made to access an element of an array that was outside it’s
bounding dimensions.
Double dimension Error
An attempt has been made to dimension an already dimensioned array. This could
be because the array was accessed previously causing it to be dimensioned by
default.
Divide by zero Error
The right hand side of an A/B expression was zero.
Illegal direct Error
An attempt was made to execute a command or function in direct mode which is
disallowed in that mode e.g. INPUT or DEF.
Type mismatch Error
An attempt was made to assign a numeric value to a string variable, a string value to
a numeric variable or a value of one type was returned when a value of the other type
was expexted or an attempt at a relational operation between a string and a number
was made.
String too long Error
String lengths can be from zero to 255 characters, more than that and you will
see this.
String too complex Error
A string expression caused an overflow on the descriptor stack. Try splitting
the expression into smaller pieces.
Can’t continue Error
Execution can’t be continued because either the program execution ended because
an error occurred, NEW or CLEAR have been executed since the program was
interrupted or the program has been edited.
Undefined function Error
FN <var> was called but not found.
LOOP without DO Error
LOOP has been encountered and no matching DO could be found.

EhBASIC requirements

Minimum requirements

  • 6502 processor.
  • 10k ROM or RAM for the interpreter code.
  • 1K of RAM from $0000.
  • RS232 I/O.

Preferred requirements

  • 6502 or better processor (65c02, CCU3000, M38xx).
  • 10k ROM or RAM for the interpreter code.
  • RAM from $0000 to $BFFF (more with changes).
  • Any character based I/O (e.g. RS232, LCD/keyboard etc).

Update EhBASIC

New Version 2.xx is here!…

7th April 2005.

Lots of changes, some small, some large. How BASIC handles functions internally has changed significantly with some major advantages for me, the code is far more easy to manage, and speed advantages for the user, about seventy cycles per value fetched. This doesn’t sound a lot but means about 140 cycles saved for any function that requires a value, and that’s most of them.

The RND() function has been changed and now uses the Galois method to generate the sequence and, as a consequence, this series has now been extended to a maximal length 32 bit series. This is about as good as any 32 bit pseudo ramdom generator can get without using more bits, or more time, and quite a lot of work went into addressing the shortcommings of other generators. It is no co-incidence that this generator now generates exactly the same sequence of numbers as that used in the 680×0 version of EhBASIC.

Some undocumented features were removed and the USR() function has been changed slightly.

Included with the source for EhBASIC is a minimal monitor to allow you to run EhBASIC on Michal Kowalski’s 6502 simulator. This also serves as an example of the minimal support code needed to run EhBASIC on other systems.

Version number is now 2.09 (2009), 2.22 (2013)

Has it really been nearly a year since the last update? Doesn’t seem like it. Most of this time has been taken with developing EhBASIC for the Mitsubishi 740 family, a 65C02 compatable cored microcontroller, and a port for the 680×0 processor. As it’s been so long a couple of version numbers have been skipped, these were never released.

The biggest change is that all keyword handling is now done with a dictionary instead of a simple list. The advantage to this is that line parsing and listing are much faster, in some cases nearly 100 times faster, and changes to keywords are now easier to do.

Another change is the way the FOR … NEXT loop operates internally. It no longer looks for current loops with the same loop variable when a FOR is executed. The advantage is faster code in a lot of places, the disadvantage is that if you jump out of a loop the stack space is never recovered. Since that’s a no-no anyway I’ve chosen to leave it like that.

Finally EhBASIC now announces the version number at startup. Any other changes are minor and are to improve speed, function or size.

Version number is now 1.10

25th July 2002.
Just a small update. The addresses where values for HEX$() or BIN$() have been changed. This frees up two bytes in page zero and is this …

nums_1		= $E0		; number to bin/hex string convert MSB
nums_2		= nums_1+1	; number to bin/hex string convert
nums_3		= nums_1+2	; number to bin/hex string convert LSB

… becomes …

nums_1		= Itempl	; number to bin/hex string convert MSB
nums_2		= nums_1+1	; number to bin/hex string convert
nums_3		= nums_1+2	; number to bin/hex string convert LSB

This is done in version 1.05
8th July 2002.
This is a re-write of the BIN$()and HEX$() functions. This frees up 8 bytes from page zero as well as being a little quicker. The downside is code length which is up slightly to 9600 bytes ($2580 bytes).

Examples of the speed increase are ..

Cycle times for HEX$(57005) and BIN$(57005)
Function Before After Saving
HEX$() 686 cycles 465 cycles 221 cycles (110uS @ 2MHz – 32%)
BIN$() 1700 cycles 1079 cycles 621 cycles (310uS @ 2MHz – 37%)

The other change is that both binary and Motorola hex versions are also available for download.

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Enhanced 6502 BASIC

Enhanced BASIC is a BASIC interpreter for the 6502 and compatible microprocessors. It is constructed to be quick and powerful and easily ported to most 6502 systems. It requires few resources to run and includes instructions to facilitate easy low level handling of hardware devices. It also retains most of the powerful high level instructions from similar BASICs.

EhBASIC represents hundreds of hours work over nearly three years, lots of frustration, lots of joy and the occasional twinge from RSI induced tendonitis.

EhBASIC is free but not copyright free. For non commercial use there is only one restriction, any derivative work should include, in any binary image distributed, the string “Derived from EhBASIC” and in any distribution that includes human readable files a file that includes the above string in a human readable form e.g. not as a comment in

With the change to v2.xx a lot of the details for the use and internal working of EhBASIC have changed!

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Mitsubishi 740 boards

The SuprDupr and SuprChip V are controller boards from DIVA Automation based on the Mitsubishi 38067 microcontroller (740 series family).

This chip is 6502 based and includes a host of onboard I/O, timers and even A to D and D to A convertors.

Software

  • Enhanced BASIC interpreter EhBASIC74
  • Port driver for the AT keyboard
  • Port driver for the LCD
  • For the SuprChip V an 8 Bit ISA bus slot
  • For the SuprChip V a network interface

SYM-1 BASIC – more nostalgia

The SYM 1 is a 6502 based SBC and was the ‘big brother’ to the KIM 1. Largely backward compatible with the KIM-1 it offered more memory, a faster tape interface, more ports etc.

SYM BASIC
This came later and is a full featured floating point BASIC with strings and arrays. It didn’t use the built in keypad and LED display but was run from an RS232 terminal device.

The version presented here is V1.1. This version did not have built in SIN(), COS(),TAN() or ATN() but did have the hooks for them to be added by an expansion ROM. These missing trig functions were common in early BASICs and manny still had the string “WANT SIN/COS/TAN/ATN”, or something similar, embedded in them long after these functions were external.

Available here is a binary image of the V1.1 8k ROM (V1.0 was allegedly in two 4k ROMs) and a fully (almost, some bits I never finished) commented disassembled listing that assembles back into that ROM using Tass 1.31.

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The Computerist

The Computerist

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The Computerist Hardware

The Computerist was a company founded by Robert M. Tripp.

On this page information on the PLUS hardware for KIM-1, AIM 65, SYM-1.. Updated April 2022 with contributions by Friedrich Hofmann.

Memory PLus van Dirk Dral, met 8K Basic in EPROM.

MICRO the 6502 Journal

Archive of the magazine Micro here.

From apple2history.org description of MICRO 6502 Journal:
Robert M. Tripp got his start with computers in 1960 as an undergraduate in an unrelated field. He found the computer programming so interesting that he became a programmer in 1969, and started with the 6502 microprocessor in 1976, initially with the KIM-1 trainer sold by MOS Technology. He started a business, “The COMPUTERIST”, and sold the KIM-1 computers, as well as software and accessories for it. He started a magazine under the umbrella of his business, and named it Micro. It began publication in October of 1977, and was released on a bimonthly basis initially, going monthly in February of 1979. The first three issues were printed using his KIM-1 and he did the paste-up for the magazine on his kitchen table. He later began to use a local publishing company to create the magazine. By early 1980 the publisher name had changed to MICRO-INK, Inc.

The magazine covered the 6502 microprocessor (and later the 6809) in all the various computers that used it, including the KIM-1, the AIM-65, the C1P, the Commodore PET, the Ohio Scientific, the Atari 800, and, of course, the Apple II. It was an excellent source for machine level code for the 6502, eventually including more and more articles that applied specifically to the Apple II. Ultimately, about half of the articles in each issue dealt with the Apple II.

Many general-purpose machine language articles appeared in its pages, such as “Improved nth Precision” (code optimization for the 6502), “Precision Programming”, and “Computer Assisted Translation Of Programs From 6502 to 6809″. They also carried do-it-yourself hardware articles, such as “C1P To Epson MX-80 Printer Interface”, “PET/CBM IEEE 448 To Parallel Printer Interface”, and “Apple II Digital Storage Oscilloscope”.

Hardware by The Computerist

The Computerist, led by Robert Tripp, not only sold software like MicroChess,  published the Micro Magazine, also designed and sold hardware.

The Dutch company, Ing. Bureau Koopmans (a one man company, active in the early years with KIM-1, OSI Scientific and such) represented The Computerist in the Netherlands, and he showed me in 1979 some of the Plus hardware series for the KIM-1, SYM-1 and AIM-65 systems:
– MEMORY PLUS: 8K RAM, 8K ROM, VIA 6522, 2716 EPROM programmer
– Proto Plus, a DIY board
– VIDEO PLUS, a glass teletype video card

I did a review of the Memory Plus in May 1979, see also the dutch magazine Radio Bulletin page.

PLUS Hardware

A range of hardware was developed and sold by the Computerist, under the brandname PLUS.

 

 

Motherboard Plus

A backplane for KIM-1/SYM-1/AIM 65. Accepts the Plus boards described below.

Memory Plus

The MEMORY PLUS board is a RAM/ROM expansion board for  KIM-1, SYM-1 or AIM65. Made by the The Computerist.

With up to 8k of RAM, 8k of (EP)ROM and the ability to program EPROMs (2716) this was quite the must have upgrade for anyone who could afford it.

Here The Manual in HTML format, original OCRed by Lee Davison, corrected and enhanced with Appendix A Circuit Diagram and Application Note #1 by Hans Otten.

Scanned by Dirk Dral, high quality scan.

And here the MEMORY PLUS manual in PDF format, Appendix A, the circuit diagrams  foldout Application Note #1 is now included, added by Hans Otten.

How to decode the 8K RAM in 4K space, an article from Micro July 1979, for AIM 65 and SYM-1 

Video Plus

VIDEO PLUS is designed to work with the KIM-1, SYM-1 and the AIM 65 computers. It offers:

  • Up to 4K  display RAM and 2K Programmable Character generator
  • 2K EPROM
  • 6845 CRT controller
  • ASCII keyboard interface
  • Composite monochrome video PAL or NTSC

The following documents are available:

Video PLUS II

Video PLUS II is an updated Video PLUS, a Versatiel Video Expansion Board, with:

  • Programmable Screen format
  • PRogrammable Character Generator
  • Uo to 4K Display Memeory
  • Supports ASCII Keyboard
  • Stand-Alone Option
  • AIM/SYM/KIM Software
  • 6845 video controller, 6522 VIA, RS232

The following documents are available:

PROTO PLUS II

The PROTO PLUS II is a board to interface digital logic to a KIM-1, SYM-1 or AIM 65. A large breadboard area is available.

The board has the standard KIM-1 44 pin edge connector. A power regulator for 8V to + 5V is on the board.

The board has  address, data bus and signal bus buffering and address decoding for tom select a 8K page in memory and kIM-1 8K decoding. 3 gates of a 74LS32 is available for general use.

Here the PROTO PLUS II manual, with circuit diagram.

 

 

DRAM Plus

DRAM Plus is a Multi-purpose Expansion Board for AIM 65/SYM-1/KIM-1 with

  • 16/32K dynamic RAM
  • 8/16K EPROM 2716/2516/2732/2532/2332
  • I/O Ports and Timers VIA 2x 6522
  • Prototyping Area
  • EPROM Programmer

DRAM PLUS manual, includes circuit diagram and software

 

 

K-1002 8 bits DAC
An 8 bits DAC. For the PET userport, easily adapted for other 6502 systems.
Hardware K-1002 manual includes circuit diagram

Files for the VIDEO and PROTO PLUS: Thanks to Dave Colglazier at Original Woodworks.

Video PLUS II and DRAM PLUS: thanks to Friedrich Hofmann

K-1008

http://www.6502.org/users/sjgray/projects/microuk101/

PBC for the UK101 project by Grant Searle.

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OSI 300 page restored

Somehow during the migration I managed to loose the OSI Model 300 trainer page.

Restored and with some additions!