Commit: b68d967e5cea256a6c148117634016d282c03704 - nsvtl (git)

Deriving a new dialect of Very Tiny Language from VTL-2 6800 version

Commit MetaInfo

• Revision: b68d967e5cea256a6c148117634016d282c03704 (tree)
• Time: 2022-09-25 19:56:00
• Author: Joel Matthew Rees <joel.rees@gmai...>
• Commiter: Joel Matthew Rees

Log Message

Went too far too fast

Change Summary

• modified: VTL_runtime.ASM

Incremental Difference

--- a/VTL_runtime.ASM
+++ b/VTL_runtime.ASM
@@ -3,7 +3,7 @@
 *	9-23-76
 *	BY GARY SHANNON
 *	& FRANK MCCOY
-*	COPYWRIGHT 1976, THE COMPUTER STORE
+*	Original version COPYRIGHT 1976, THE COMPUTER STORE
 *
 *	Modified 2022 by Joel Rees
 *
@@ -56,13 +56,14 @@ RSTKSZ	EQU 24		; 2 bytes per call, room for interrupts
 
 *	DEFINE LOCATIONS IN MONITOR
 * INCH	EQU	$FF00	; per VTL.ASM
-* INCH	EQU	$F012	; exorsim mdos Input byte with echo unless AECHO is set
+EINCH	EQU	$F012	; exorsim mdos Input byte with echo unless AECHO is set
 * INCH	EQU	$F015	; exorsim mdos Input char with echo (F012 -> strip bit 7)
 * POLCAT	EQU	$FF24	; from VTL.ASM
 * POLCAT	EQU	POLCATROB	; dummy return, assume INCH takes care of things
 * OUTCH	EQU	$FF81	; from VTL.ASM
-* OUTCH	EQU	$F018	; exorsim mdos Output character with NULs
+EOUTCH	EQU	$F018	; exorsim mdos Output character with NULs
 * OUTS	EQU	$FF82	; from VTL.ASM
+EPCRLF	EQU	$F021	; Primarily for forced initialization in exorsim.
 ******* Want to define these at bottom because of POLCAT, but ...
 *
 *	FOR SBC6800
@@ -167,13 +168,13 @@ USTKINI	EQU *
 
 RSTKLIM	RMB	RSTKSZ
 RSTKINI	EQU *
-STACK	EQU 	RSTKINI-1	; See TSX/TXS function for why.
+STACK	EQU 	RSTKINI-1	; See TSX/TXS op-code for why.
 	RMB	8		; buffer zone
 
 STALTOP	EQU *
 
 
-* Most assemblers are scared of address calculations,
+* Most early assemblers are scared of address calculations,
 * So do this in your head:
 * 	IF STATLIM >= ALLIMIT
 *	ERROR "Move stack allocations higher!"
@@ -196,15 +197,16 @@ CODE	EQU *
 PRGM	EQU	*	; PROGRAM STARTS HERE
 *
 *
-START	LDS	#STACK	; S on 6800 is first free byte on stack.
-	LDX	#USTKINI	; U stack will be top byte (last pushed).
-	STX	vUSP
+	ORG	$7800
+COLD	LDS	#STACK	; S on 6800 is first free byte on stack.
+	JSR	TRMINI
 	LDX	#GLOBASE
 	STX	vTASK
-	BRA	REALSTART
+START
+	LDS	#STACK	; reset the stack
+	LDX	#USTKINI	; U stack will be top byte (last pushed).
+	STX	vUSP
 *
-	
-REALSTART
 	CLRA
 	LDX	#OKM
 	BSR	STRGT
@@ -667,8 +669,11 @@ INLN6	CMPB	#'@	; CANCEL
 	BNE	INLN2
 NEWLIN	BSR	CRLF
 *
-INLN	LDX	#2	; INPUT LINE FROM TERMINAL
+INLN	LDX	vTASK	;#2	; INPUT LINE FROM TERMINAL
+	INX
+*************
 INLN5	DEX
+	CPX
 	BEQ	NEWLIN
 INLN2	JSR	INCH	; INPUT CHARACTER
 	STAB	$87,X	; STORE IT
@@ -683,6 +688,7 @@ INLIN4	CLR	$87,X	; CLEAR LAST CHAR
 	LDX	#LINBUF
 	BRA	LF
 *
+*CRLF	JSR	EPCRLF
 CRLF	LDAB	#$0D	; CARR-RET
 	BSR	OUTCH2
 LF	LDAB	#$0A	; LINE FEED
@@ -690,34 +696,38 @@ OUTCH2	JMP	OUTCH
 *
 OKM	FCB	$0D
 	FCB	$0A
+	FCC	'              DONE'
+	FCB	$0D
+	FCB	$0A
 	FCC	'OK'
 	FCB	$00
 *
-*	RECIVE POLING
+TRMINI	LDAB #40
+TRMILP	JSR EPCRLF
+	DECB
+	BNE TRMILP
+	RTS
+*
+*	RECEIVER POLLING
 POLCAT	LDAB	ACIACS
 	ASRB
 	RTS
 *
-*	INPUT ONE CHAR INTO A-REGISTER
-INCH	BSR	POLCAT
-	BCC	INCH	RECEIVE NOT READY
-	LDAB	ACIADA	INPUT CHARACTER
-	ANDB	#$7F	RESET PARITY BIT
-	CMPB	#$7F
-	BEQ	INCH	IF RUBOUT, GET NEXT CHAR
-	BSR	OUTCH
+*	INPUT ONE CHAR INTO B ACCUMULATOR
+INCH	PSHA
+	JSR	EINCH
+	TAB
+	PULA
 	RTS
 *
 *	OUTPUT ONE CHAR 
-OUTCH	PSHB
-OUTCH1	BSR	POLCAT
-	ASRB
-	BCC	OUTCH1
-	PULB
-	STAB	ACIADA
+OUTCH	PSHA
+	TBA
+	JSR	EOUTCH
+	PULA
 	RTS
 *
-	ORG START
+	ORG COLD
 *
 	END