OBJNAM OCTPCH.LIT ; Created 21-Nov-84, Last modified 16-Apr-86
; by Irv Bromberg, Medic/OS Consultants, 78 Wildginger Way, Toronto,
; CANADA  M3H 5X1
RADIX 10
VEDIT=14
VMINOR=0
VMAJOR=4
VSUB=0

IF EQ,1
Edit history:
16-Apr-86 4.0(14) change J.DEC to most significant bit of JOBTYP(JCB) for
		  compatability with AMOS/L 1.3C and later, require J.DEC
		  to be defined in MAC:SYS.M68 & reassemble SYS.M68
4-Dec-85 3.3A(13)

Syntax: OCTPCH

Installs OCVT patch into SVCA table.  Must be used before any
SYSTEM commands are used in AMOSL.INI file, preferably as early
as possible (e.g. after first TRMDEF statement).

ENDC

SEARCH SYS
; Must add to MAC:SYS.M68:  J.DEC=^H8000 (belongs in the JOBTYP section)
; then reassemble file to create updated MAC:SYS.UNV
SEARCH SYSSYM

JCB	=A0
Block	=A1
Table	=A2
Buffer	=A2
Patch	=A3
Atemp	=A6

Number	=D1
Size	=D2

	PHDR	-1,0,PH$REE!PH$REU

; bypass patch if already installed - test by attempted DEC output
	MOV	JOBCUR,JCB		; save existing OCT/DEC/HEX mode bits
	PUSHW	JOBTYP(JCB)
	ORW	#<J.DEC!J.HEX>,JOBTYP(JCB) ; set DEC mode
	PUSHW				; get some workspace
	MOV	SP,Buffer
	MOV	#11.,Number		; output the number 11 - if DEC patch
	OCVT	0,OT$MEM		; not active result will be "B"
	POPW	Number
	POPW	JOBTYP(JCB)		; restore original OCT/DEC/HEX mode
	CMPW	Number,#<'1_8.+'1>	; did we get "11" ?
	BNE	ChkUP			; no, check if system is up yet
	TYPECR	<%OCVT patch already installed>
	EXIT

ChkUP:	MOV	SYSTEM,D7		; has final SYSTEM command been given?
	AND	#SY$UP,D7
	BEQ	ChkSYS			; if so abort with error message
Before:	TYPECR	<?OCVT patch must be installed before any SYSTEM commands>
	EXIT
ChkSYS:	TST	SYSBAS			; any SYSTEM commands executed?
	BNE	Before			; yes, abort with error message

ChkRNG:	MOV	MEMBAS,Block		; are we within range to install patch?
	CMP	Block,#^H0FFFF
	BLO	DoPCH
	TYPECR	<?Too late to install OCVT patch - out of addressing range>
	EXIT
	
DoPCH:	MOV	MEMBAS,Block		; index available memory
	LEA	Patch,PRGBAS		; index OCVT patch routine
	MOVW	#<PRGEND-PRGBAS-2>,Size	; get size of block (-2/2 for DBF loop)
	LSRW	Size			; /2 for 16-bit word block move
	MOV	^O50,Table		; get address of EM1010 routine
Search:	CMPW	(Table)+,#^O47165	; search for RTN instruction, leaving
	BNE	Search			; Table register -->base of SVCA table
	ADD	#2*^O12,Table		; add offset to DCVT/OCVT SVCA
	; install original TRMOCP SVCA address
	LEA	Atemp,OrigCvt+4
	MOVW	@Table,@Atemp		; save original SVCA 12 address
BlkMov:	MOVW	(Patch)+,(Block)+	; copy OCVT patch onto end of monitor
	DBF	Size,BlkMov
	MOV	MEMBAS,Atemp		; get address of new SVCA 12 entry point
	MOVW	Atemp,@Table		; set new SVCA 12 entry point
	MOV	Block,MEMBAS		; update MEMBAS
	TYPECR	<OCVT patched>		; successfull!
	EXIT

IF EQ,1

Patch for OCVT monitor call.  Tests J.DEC bit in JOBTYP(JCB).  If
set then interprets all OCVT as DCVT.  To install into monitor must
add OCTPCH statement to AMOSL.INI bootup file. Because the patch
must be within 64K addressing range of the SVCA table the OCTPCH
statement should be executed early in the AMOSL.INI file - after the
first TRMDEF statement is a convenient location.  OCTPCH must be
executed prior to any SYSTEM command.

ENDC

; OCTPCH.LIT changes SVCA 12 entry in monitor-call table to point here:

PRGBAS:	PUSH	JCB			; new destination of SVCA 12
	MOV	JOBCUR,JCB		; index JCB
	BTST	#4,JOBTYP(JCB)		; check J.HEX bit
	BEQ	OrigCvt			; octal base, do normal OCTAL output
	TSTW	JOBTYP(JCB)		; check J.DEC bit
	BPL	OrigCvt			; J.DEC not set, do normal HEX output
	ANDW	#^C<^O40000>,D6		; switch to DCVT
OrigCvt:POP	JCB
	JMP	0  ; original OCVT address put here by OCTPCH.LIT
PRGEND:	NOP

	END
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