2024/05/27 : Initial commit

.gitignore

@@ -0,0 +1,49 @@
+# Prerequisites
+*.d
+*.bat
+
+# Object files
+*.o
+*.ko
+*.obj
+build/
+
+# Linker output
+*.ilk
+*.map
+*.exp
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+# Debug files
+*.dSYM/
+*.su
+*.idb
+*.pdb
+
+# Editor files
+*~
+#*
+.#*

README.md

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+# BBCZ80
+BBC BASIC (Z80) v5 is an implementation of the BBC BASIC programming language for the Z80 CPU.
+It is largely compatible with Acorn's ARM BASIC V but with a few language extensions based on
+features of 'BBC BASIC for Windows' and 'BBC BASIC for SDL 2.0'. These extensions include the
+EXIT statement, the address-of operator (^) and byte (8-bit) variables and arrays (& suffix).
+
+More details of the features added in version 5.00 can be found in the file WHATSNEW.TXT.
+
+![Architecture](https://www.bbcbasic.co.uk/bbcbasic/z80arch.png)
+
+The files in green constitute the generic BBC BASIC interpreter which is shared by all the
+editions, it (just!) fits in 16 Kbytes so could be held in a ROM of this size.  The files in
+the blue box are used to build the CP/M edition.  The files in the red box are used to build
+the Acorn Z80 Second Processor edition (in principle: the source files are on an 8" floppy!)
+
+Note that the name 'BBC BASIC' is used by permission of the British Broadcasting Corporation
+and is not transferrable to a derived or forked work.

WHATSNEW.TXT

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+New features in BBC BASIC (Z80) version 5.00, May 2024:
+
+1. BASIC V statements
+
+1.1  WHILE...ENDWHILE
+1.2  Multi-line IF...THEN...ELSE...ENDIF
+1.3  CASE...WHEN...OTHERWISE...ENDCASE
+1.4  LOCAL DATA / RESTORE DATA
+1.5  ON ERROR LOCAL / RESTORE ERROR
+1.6  DIM var LOCAL size 
+1.7  ERROR err, message$
+1.8  RESTORE +n
+1.9  SWAP var1,var2
+1.10 BPUT #file,string$[;]
+1.11 QUIT
+
+2. BASIC V functions
+
+2.1  DIM(array()[,sub])
+2.2  END (pointer to free space)
+2.3  REPORT$
+2.4  Binary constants
+2.5  LEFT$ & RIGHT$ with last parameter omitted
+2.6  MOD(array)
+2.7  SUM(array)
+2.8  SUMLEN(array)
+2.9  GET$#file 
+
+3. BASIC V whole array operations
+
+3.1  Pass a whole array to a FN/PROC
+3.2  Pass a whole array to CALL
+3.3  Whole array assignment
+3.4  Whole array arithmetic *
+3.5  Array dot-product operator
+3.6  Array initialisation lists
+3.7  Array compound assignment (+= etc.)
+3.8  Make a whole array LOCAL
+3.9  DIM a LOCAL array (on the stack) + 
+
+* String array expressions A$() = B$() + C$() are not currently supported.
++ LOCAL string arrays should be initialised to their maximum needed length
+  to eliminate the risk of a memory leak each time the PROC/FN is called:
+     LOCAL a$() : DIM a$(size%) : a$() = STRING$(max%, "a") : a$() = ""
+
+4. Miscellaneous BASIC V features
+
+4.1  Bit-shifts <<, >>, >>>
+4.2  Floating-point indirection (|)
+4.3  RETURNed parameters from FN/PROC
+4.4  Compound assignment (+=, -=, *=, /= etc.)
+4.5  Assigning to a sub-string: LEFT$()=, MID$()= , RIGHT$()=
+4.6  Hooks for CIRCLE,ELLIPSE,FILL,LINE,MOUSE,ORIGIN,RECTANGLE,TINT,SYS,WAIT
+4.7  Hooks for WIDTH function, TINT function, MODE function
+
+5. Extensions to Acorn's BASIC V, compatible with BB4W, BBCSDL and BBCTTY
+
+5.1  EXIT REPEAT / WHILE / FOR [var]
+5.2  Address-of operator ^
+5.3  Byte variables and arrays (& suffix)
+5.4  'BY len' and 'TO term' qualifiers to GET$#file
+5.5  ELSE IF <condition> THEN; (trailing semicolon)
+5.6  == synonymous with = in comparisons
+5.7  DIM a global array inside a FN/PROC (use RETURN)
+
+Note: The token for PUT has changed from &CE in version 3 to &0E in version 5.
+If this token is present in existing programs it will list as ENDWHILE rather
+than PUT, and the programs will need to be modified to restore functionality.

bin/cpm/MAKE.SUB

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+m80 dist,dist.lst=dist.z80 /z
+m80 main,main.lst=main.z80 /z
+m80 exec,exec.lst=exec.z80 /z
+m80 eval,eval.lst=eval.z80 /z
+m80 asmb,asmb.lst=asmb.z80 /z
+m80 cmos,cmos.lst=cmos.z80 /z
+m80 math,math.lst=math.z80 /z
+m80 hook,hook.lst=hook.z80 /z
+m80 data,data.lst=data.z80 /z
+era bbcbasic.com
+link bbcbasic=dist,main,exec,eval,asmb,math,hook,cmos,/p:4B00,data
+hexbin bbcbasic
+era bbcbasic.hex
+ren bbcbasic.com=bbcbasic.bin

licence.txt

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+Copyright (c) 2024, Richard T. Russell, http://www.rtrussell.co.uk/
+
+This software is provided 'as-is', without any express or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software.  If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required.
+
+2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+
+3. This notice may not be removed or altered from any source distribution.

src/DATA.Z80

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+	TITLE	BBC BASIC (C) R.T.RUSSELL 1981-2024
+;
+;RAM MODULE FOR BBC BASIC INTERPRETER
+;FOR USE WITH VERSION 5.0 OF BBC BASIC
+;(C) COPYRIGHT R.T.RUSSELL 1981-2024
+;
+	GLOBAL	ACCS
+	GLOBAL	BUFFER
+	GLOBAL	ONERSP
+	GLOBAL	LIBASE
+	GLOBAL	PAGE
+	GLOBAL	LOMEM
+	GLOBAL	FREE
+	GLOBAL	HIMEM
+	GLOBAL	RANDOM
+	GLOBAL	COUNT
+	GLOBAL	WIDTH
+	GLOBAL	ERL
+	GLOBAL	ERR
+	GLOBAL	ERRTRP
+	GLOBAL	ERRTXT
+	GLOBAL	TRACEN
+	GLOBAL	AUTONO
+	GLOBAL	INCREM
+	GLOBAL	LISTON
+	GLOBAL	DATPTR
+	GLOBAL	FNPTR
+	GLOBAL	PROPTR
+	GLOBAL	STAVAR
+	GLOBAL	OC
+	GLOBAL	PC
+	GLOBAL	DYNVAR
+	GLOBAL	CURLIN
+	GLOBAL	USER
+;
+;n.b. ACCS, BUFFER & STAVAR must be on page boundaries.
+;
+ACCS:	DEFS	256		;STRING ACCUMULATOR
+BUFFER:	DEFS	256		;STRING INPUT BUFFER
+STAVAR:	DEFS	27*4		;STATIC VARIABLES
+OC	EQU	STAVAR+15*4	;CODE ORIGIN (O%)
+PC	EQU	STAVAR+16*4	;PROGRAM COUNTER (P%)
+DYNVAR:	DEFS	54*2		;DYN. VARIABLE POINTERS
+FNPTR:	DEFS	2		;DYN. FUNCTION POINTER
+PROPTR:	DEFS	2		;DYN. PROCEDURE POINTER
+;
+PAGE:	DEFS	2		;START OF USER PROGRAM
+LOMEM:	DEFS	2		;START OF DYN. STORAGE
+FREE:	DEFS	2		;FIRST FREE-SPACE BYTE
+HIMEM:	DEFS	2		;FIRST BYTE ABOVE STACK
+LIBASE:	DEFS	2		;START OF FIRST LIBRARY
+;
+TRACEN:	DEFS	2		;TRACE FLAG AND NUMBER
+AUTONO:	DEFS	2		;AUTO FLAG AND NUMBER
+ERRTRP:	DEFS	2		;ON ERROR STMT POINTER \
+ONERSP:	DEFS	2		;ON ERROR LOCAL STKPTR /
+ERRTXT:	DEFS	2		;ERROR MESSAGE POINTER
+DATPTR:	DEFS	2		;DATA POINTER
+ERL:	DEFS	2		;LINE NO OF LAST ERROR
+CURLIN:	DEFS	2		;POINTER TO CURRENT LINE
+RANDOM:	DEFS	5		;RANDOM NUMBER
+COUNT:	DEFS	1		;PRINT POSITION
+WIDTH:	DEFS	1		;PRINT WIDTH
+ERR:	DEFS	1		;ERROR NUMBER
+LISTON:	DEFS	1		;LISTO & OPT FLAG
+INCREM:	DEFS	1		;AUTO INCREMENT
+;
+USER:	END

src/DIST.Z80

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+	TITLE	BBCDIST.Z80 (C) R.T.RUSSELL 1982-2024
+;
+;BBC BASIC (Z80) - CP/M VERSION 2.20 & 3.00
+;(C) COPYRIGHT R.T.RUSSELL, 1982-2024.
+;ALL RIGHTS RESERVED.
+;
+;THIS PROGRAM ALLOWS THE USER TO ADAPT BBC BASIC TO THE
+;PARTICULAR CHARACTERISTICS OF HIS SYSTEM HARDWARE ETC.
+;
+;THE PROGRAM RESIDES AT 100H FOR EASE OF LOADING.
+;*** IT MUST NOT EXCEED 256 BYTES IN TOTAL LENGTH ***
+;
+;PLEASE NOTE THAT A Z80 PROCESSOR AND CP/M VERSION 2.2
+;OR LATER ARE REQUIRED.
+;
+;R.T.RUSSELL, 11-03-1984, 03-05-1989, 12-05-2024
+;
+CPM	EQU	5
+COLD	EQU	200H
+;
+	GLOBAL	CLRSCN
+	GLOBAL	PUTCSR
+	GLOBAL	GETCSR
+	GLOBAL	PUTIME
+	GLOBAL	GETIME
+	GLOBAL	GETKEY
+	GLOBAL	BYE
+;
+	ASEG
+	ORG	100H
+;
+;JUMP TABLE - BASIC makes calls to hardware-dependent
+;features via this table:
+;
+	JP	INIT
+CLRSCN:	JP	CLS		;CLEAR SCREEN
+PUTCSR:	JP	PCSR		;SET CURSOR POSN.
+GETCSR:	JP	GCSR		;READ CURSOR POSN.
+PUTIME:	JP	PTIME		;SET ELAPSED TIME
+GETIME:	JP	GTIME		;READ ELAPSED TIME
+GETKEY:	JP	INKEY		;READ KEY (TIME LIMIT)
+BYE:	JP	REBOOT		;RETURN TO CP/M
+;
+;BDOS	- Save the IX and IY registers and before performing a
+;	  CP/M function call.
+;
+BDOS:	PUSH	IX
+	PUSH	IY
+	CALL	CPM
+	POP	IY
+	POP	IX
+	RET
+;
+;INIT	- Perform hardware initialisation (if any).
+;
+INIT:	LD	A,2
+	INC	A
+	LD	DE,NOTZ80
+	JP	PE,FAIL
+	LD	C,12
+	CALL	BDOS
+	OR	A
+	LD	DE,NOTV2
+	JP	NZ,COLD
+FAIL:	LD	C,9
+	CALL	BDOS
+	RST	0
+;
+NOTZ80:	DEFB	'Not a Z80$'
+NOTV2:	DEFB	'Not CP/M 2$'
+;
+;REBOOT	- Switch off interrupts and return to CP/M
+;
+REBOOT:	RST	0
+;
+;GTIME	- Read elapsed-time clock.
+;  	  Outputs: DEHL = elapsed time (centiseconds)
+; 	  Destroys: A,D,E,H,L,F
+;
+GTIME:	PUSH	BC
+	CALL	TICKS
+	LD	BC,(OFFLO)
+	ADD	HL,BC
+	EX	DE,HL
+	LD	BC,(OFFHI)
+	ADC	HL,BC
+	EX	DE,HL
+	POP	BC
+	RET
+;
+;PTIME	- Load elapsed-time clock.
+;   	  Inputs: DEHL = time to load (centiseconds)
+; 	  Destroys: A,D,E,H,L,F
+;
+PTIME:	PUSH	BC
+	PUSH	DE
+	PUSH	HL
+	CALL	TICKS
+	LD	B,H
+	LD	C,L
+	POP	HL
+	OR	A
+	SBC	HL,BC
+	LD	(OFFLO),HL
+	LD	B,D
+	LD	C,E
+	POP	HL
+	SBC	HL,BC
+	LD	(OFFHI),HL
+	POP	BC
+	RET
+;
+; Get OS elapsed-time clock
+;  Outputs: DEHL = time (centiseconds)
+; Destroys: A,B,C,D,E,H,L,F
+;
+TICKS:	LD	C,248		;RunCPM-specific function call
+	CALL	BDOS
+	PUSH	DE
+	EX	DE,HL
+	OR	A
+	SBC	HL,HL
+	LD	BC,-5
+	LD	A,32
+DIV0:	ADD	HL,BC
+	JR	C,DIV1
+	SBC	HL,BC
+DIV1:	RL	E
+	RL	D
+	EX	(SP),HL
+	RL	L
+	RL	H
+	EX	(SP),HL
+	ADC	HL,HL
+	DEC	A
+	JR	NZ,DIV0
+	EX	DE,HL
+	POP	DE
+	RET
+;
+;INKEY	- Sample keyboard with specified wait.
+;   	  Inputs: HL = Time to wait (centiseconds)
+;  	  Outputs: Carry reset indicates time-out.
+;                  If carry set, A = character typed.
+; 	  Destroys: A,D,E,H,L,F
+;
+INKEY:	PUSH	BC
+	PUSH	HL
+	CALL	TICKS
+	POP	DE
+	ADD	HL,DE
+WAIT:	PUSH	HL
+	LD	C,6
+	LD	E,0FFH
+	CALL	BDOS
+	POP	HL
+	OR	A
+	SCF
+	JR	NZ,INKEY1
+	PUSH	HL
+	CALL	TICKS
+	POP	DE
+	SBC	HL,DE
+	EX	DE,HL
+	JR	C,WAIT	
+INKEY1:	POP	BC
+	RET
+;
+;CLS	- Clear screen.
+;	  (Customise to suit your VDU)
+; 	  Destroys: A,D,E,H,L,F
+;
+CLS:	RET
+;
+;PCSR	- Move cursor to specified position.
+;   	  Inputs: DE = horizontal position (LHS=0)
+;                 HL = vertical position (TOP=0)
+; 	  Destroys: A,D,E,H,L,F
+;
+PCSR:	RET
+;
+;GCSR	- Return cursor coordinates.
+;   	  Outputs:  DE = X coordinate (POS)
+;                   HL = Y coordinate (VPOS)
+;  	  Destroys: A,D,E,H,L,F
+;
+GCSR:	LD	DE,0
+	LD	HL,0
+	RET
+;
+;COUT - Output a character to the console
+;   Inputs: A = character
+; Destroys: A,F
+;
+COUT:	PUSH	BC
+	PUSH	DE
+	PUSH	HL
+	LD	E,A
+	LD	C,2
+	CALL	BDOS
+	POP	HL
+	POP	DE
+	POP	BC
+	RET
+;
+	IF	$ GT 1F0H
+	ERROR	'INSUFFICIENT SPACE'
+	ENDIF
+;
+	ORG	1F0H
+;
+OFFLO:	DEFW	0		;TIME OFFSET LO
+OFFHI:	DEFW	0		;TIME OFFSET HI
+	DEFB	80		;WIDTH
+	DEFB	'G' AND 1FH	;CURSOR UP
+	DEFB	'O' AND 1FH	;CURSOR DOWN
+	DEFB	'F' AND 1FH	;START OF LINE
+	DEFB	'N' AND 1FH	;END OF LINE
+	DEFB	'X' AND 1FH	;DELETE TO END OF LINE
+	DEFB	08H		;BACKSPACE & DELETE
+	DEFB	'U' AND 1FH	;DEL TO START OF LINE
+	DEFB	'J' AND 1FH	;CURSOR LEFT
+	DEFB	'L' AND 1FH	;CURSOR RIGHT
+	DEFB	'R' AND 1FH	;DELETE CHARACTER
+	DEFB	'Q' AND 1FH	;INS/OVR TOGGLE
+;
+FIN:	END

src/HOOK.Z80

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+;
+	GLOBAL	CLG
+	GLOBAL	COLOUR
+	GLOBAL	DRAW
+	GLOBAL	ENVEL
+	GLOBAL	GCOL
+	GLOBAL	MODE
+	GLOBAL	MOVE
+	GLOBAL	PLOT
+	GLOBAL	SOUND
+	GLOBAL	PUTIMS
+	GLOBAL	CIRCLE
+	GLOBAL	ELLIPSE
+	GLOBAL	FILL
+	GLOBAL	MOUSE
+	GLOBAL	ORIGIN
+	GLOBAL	RECTAN
+	GLOBAL	LINE
+	GLOBAL	TINT
+	GLOBAL	WAIT
+	GLOBAL	SYS
+;
+	GLOBAL	ADVAL
+	GLOBAL	POINT
+	GLOBAL	GETIMS
+	GLOBAL	TINTFN
+	GLOBAL	MODEFN
+	GLOBAL	WIDFN
+;
+	EXTRN	EXTERR
+;
+CLG:
+COLOUR:
+DRAW:
+ENVEL:
+GCOL:
+MODE:
+MOVE:
+PLOT:
+SOUND:
+ADVAL:
+POINT:
+GETIMS:
+PUTIMS:
+CIRCLE:
+ELLIPSE:
+FILL:
+MOUSE:
+ORIGIN:
+RECTAN:
+LINE:
+TINT:
+TINTFN:
+MODEFN:
+WIDFN:
+WAIT:
+SYS:
+	XOR	A
+	CALL	EXTERR
+	DEFM	'Sorry'
+	DEFB	0
+;
+	END