From 2d04cacc5322951f187bb17e017c12920ac8ebe2 Mon Sep 17 00:00:00 2001
From: Mark Zbikowski
Date: Thu, 25 Apr 2024 21:24:10 +0100
Subject: MZ is back!

---
 v4.0/src/CMD/REPLACE/_REPLACE.ASM | 142 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)
 create mode 100644 v4.0/src/CMD/REPLACE/_REPLACE.ASM

(limited to 'v4.0/src/CMD/REPLACE/_REPLACE.ASM')

diff --git a/v4.0/src/CMD/REPLACE/_REPLACE.ASM b/v4.0/src/CMD/REPLACE/_REPLACE.ASM
new file mode 100644
index 0000000..b8071d8
--- /dev/null
+++ b/v4.0/src/CMD/REPLACE/_REPLACE.ASM
@@ -0,0 +1,142 @@
+page	60,132				;
+name	_replace
+title	Critical error or control break exit
+;-------------------------------------------------------------------
+;
+;	MODULE: 	_replace
+;
+;	PURPOSE:	Supplies assembler exit routines for
+;			critical error or control break situations
+;
+;	CALLING FORMAT:
+;			crit_err_handler;
+;			ctl_brk_handler;
+;
+;	DATE:		10/87
+;
+;-------------------------------------------------------------------
+
+
+	public	_crit_err_handler	;AN000;
+	public	_ctl_brk_handler	;AN000;
+
+;-------------------------------------------------------------------
+RET_EXIT equ	4ch			; terminate				;AN000;
+CTLBRK	equ	3			; errorlevel return in al		;AN000;
+ABORT	equ	2			; if >=, retry				;AN000;
+XABORT	equ	1			; errorlevel return in al		;AN000;
+;-------------------------------------------------------------------
+
+
+NULL	SEGMENT PARA PUBLIC 'BEGDATA'	;AN000;
+NULL	ENDS				;AN000;
+_DATA	SEGMENT PARA PUBLIC 'DATA'	;AN000;
+	extrn	_oldint24:dword 	;AN000;
+_DATA	ENDS				;AN000;
+CONST	SEGMENT WORD PUBLIC 'CONST'	;AN000;
+CONST	ENDS				;AN000;
+_BSS	SEGMENT WORD PUBLIC 'BSS'	;AN000;
+_BSS	ENDS				;AN000;
+STACK	SEGMENT PARA STACK 'DATA'	;AN000;
+STACK	ENDS				;AN000;
+
+PGROUP	GROUP	_TEXT			;AN000;
+DGROUP	GROUP	NULL, _DATA, CONST, _BSS, STACK ;AN000;
+
+
+
+_TEXT	segment para public 'CODE'	;AN000;
+	ASSUME	CS:PGROUP		;AN000;
+
+	extrn	_restore:near		;AN000;
+
+;-------------------------------------------------------------------
+; CRITICAL ERROR HANDLER
+;-------------------------------------------------------------------
+vector	dd	0			;receives a copy of _oldint24		;AN000;
+
+_crit_err_handler proc near		;AN000;
+
+	pushf				; req by int24 handler			;AN000;
+	push	ax			; will use ax				;AN000;
+	push	ds			; will use ds				;AN000;
+
+	mov	ax,dgroup		; setup 				;AN000;
+	mov	ds,ax			;					;AN000;
+	ASSUME	DS:DGROUP		;AN000;
+
+	mov	ax,word ptr _oldint24	; load vector so we can use it		;AN000;
+	mov	word ptr vector,ax	;					;AN000;
+	mov	ax,word ptr _oldint24+2 ;					;AN000;
+	mov	word ptr vector+2,ax	;					;AN000;
+
+	pop	ds			; finished with ds			;AN000;
+	ASSUME	DS:NOTHING
+
+	pop	ax			; finished with ax			;AN000;
+
+	call	dword ptr vector	; invoke DOS err hndlr			;AN000;
+
+	cmp	al,ABORT		; what was the user's response          ;AN000;
+	jnge	retry			;					;AN000;
+
+	mov	ax,(RET_EXIT shl 8)+XABORT ; return to DOS w/criterr error	;AN000;
+	call	call_restore		; restore user's orig append/x          ;AN000;
+; =================== this call does not return ===============
+
+retry:					;AN000;
+	ASSUME	DS:NOTHING
+	ASSUME	ES:NOTHING
+
+	iret				; user response was "retry"		;AN000;
+
+_crit_err_handler endp			;AN000;
+
+
+;-------------------------------------------------------------------
+; CONTROL BREAK HANDLER
+;-------------------------------------------------------------------
+_ctl_brk_handler proc near		;AN000;
+
+	ASSUME	DS:NOTHING
+	ASSUME	ES:NOTHING
+
+	mov	ax,(RET_EXIT shl 8)+CTLBRK ; return to DOS w/ctlbrk error	;AN000;
+;-------------------------------------------------------------------
+	call	call_restore		; restore user's orig append/x          ;AN000;
+;-------------------------------------------------------------------
+; =================== this call does not return ===============
+
+_ctl_brk_handler endp			;AN000;
+
+call_restore proc near
+;input: ah has the RETURN TO DOS WITH RET CODE function request
+;	al has the ERRORLEVEL return code to be passed back to DOS
+;output: this routine does NOT RETURN, but exits to DOS with ret code.
+
+	push	ax			;save errorlevel return code
+	push	ds
+	push	es
+
+	mov	ax,dgroup		; setup "c" code regs			;AN000;
+	mov	ds,ax			;					;AN000;
+	ASSUME	DS:DGROUP		;AN000;
+
+	mov	es,ax			;					;AN000;
+	ASSUME	ES:DGROUP		;AN000;
+
+;-------------------------------------------------------------------
+	call	_restore		; restore user's orig append/x          ;AN000;
+;-------------------------------------------------------------------
+
+	pop	es
+	pop	ds
+	pop	ax			;restore return code
+	int	21h			;					;AN000;
+	int	20h			; in case int21 fails			;AN000;
+
+call_restore endp
+
+_TEXT	ends				; end code segment			;AN000;
+	end				;AN000;
+
\ No newline at end of file
-- 
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