From d534aa41d53b8b286511374c6934c061860625b3 Mon Sep 17 00:00:00 2001
From: Wayne Warthen <wwarthen@gmail.com>
Date: Mon, 11 May 2020 09:47:30 -0700
Subject: [PATCH] Fix CPM3/ZPM3 Disk Reassignment Issue

- Improve the behavior of the ASSIGN command to notify CPM3/ZPM3 BDOS of disk change when a drive is reassigned.
---
 Source/Apps/Assign.asm | 22 +++++++++++++++++++++-
 Source/CPM3/diskio.z80 |  7 ++++---
 Source/ver.inc         |  2 +-
 Source/ver.lib         |  2 +-
 4 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/Source/Apps/Assign.asm b/Source/Apps/Assign.asm
index 4e1606b4..c6214c65 100644
--- a/Source/Apps/Assign.asm
+++ b/Source/Apps/Assign.asm
@@ -25,6 +25,7 @@
 ;   2019-12-24 [WBW] Fixed location of BIOS save area\
 ;   2020-04-29 [WBW] Updated for larger DPH (16 -> 20 bytes)
 ;   2020-05-06 [WBW] Add patch level to version compare
+;   2020-05-10 [WBW] Set media change flag in XDPH for CP/M 3
 ;_______________________________________________________________________________
 ;
 ; ToDo:
@@ -777,6 +778,10 @@ instc2:
 	inc	hl		; bump to slice field of DPH field
 	ld	a,(de)		; get slice from mapwrk
 	ld	(hl),a		; put slice into DPH field
+	ld	a,11		; media byte is 11 bytes ahead
+	call	addhl		; bump HL to media byte adr
+	or	$FF		; use $FF to signify media change
+	ld	(hl),a		; set media flag byte
 	inc	de		; bump to next mapwrk entry
 	inc	de		; ...
 	inc	de		; ...
@@ -800,6 +805,16 @@ instc3:
 	add	hl,de		; HL := SELMEM func
 	ld	a,1		; bank 1 is tpa bank
 	call	jphl
+;
+	; set SCB drive door open flag
+	ld	a,$54		; SCB drive door opened flag
+	ld	(scboff),a	; set offset parm
+	or	$FF		; SCB operation, $FF = set
+	ld	(scbop),a	; set operation parm
+	ld	(scbval),a	; set value parm to $FF
+	ld	c,$31		; get/set system control block
+	ld	de,scbpb	; scb parameter block adr
+	call	bdos
 ;
 	call	drvrst		; perform BDOS drive reset
 ;
@@ -1828,6 +1843,11 @@ heaplim	.dw	0		; heap limit address
 ;
 dirbuf	.dw	0		; directory buffer location
 ;
+scbpb:	; BDOS SCB get/set parm block
+scboff	.db	$54		; media open door flag
+scbop	.db	$FF		; set a byte
+scbval	.dw	$FF		; value to set
+;
 mapwrk	.fill	(4 * 16),$FF	; working copy of drive map
 ;
 devtbl:				; device table
@@ -1872,7 +1892,7 @@ stack	.equ	$		; stack top
 ; Messages
 ;
 indent	.db	"   ",0
-msgban1	.db	"ASSIGN v1.2 for RomWBW CP/M, 7-May-2020",0
+msgban1	.db	"ASSIGN v1.3 for RomWBW CP/M, 10-May-2020",0
 msghb	.db	" (HBIOS Mode)",0
 msgub	.db	" (UBIOS Mode)",0
 msgban2	.db	"Copyright 2020, Wayne Warthen, GNU GPL v3",0
diff --git a/Source/CPM3/diskio.z80 b/Source/CPM3/diskio.z80
index ec3ff124..1856eefa 100644
--- a/Source/CPM3/diskio.z80
+++ b/Source/CPM3/diskio.z80
@@ -195,7 +195,8 @@ dpb$max:
 	dw  	1024 - 1	; drm: dir entries - 1
 	db  	11111111b	; al0: dir blk bit map, first byte
 	db  	00000000b	; al1: dir blk bit map, second byte
-	dw  	64		; cks: directory check vector size - 256 / 4
+	;dw  	64		; cks: directory check vector size - 256 / 4
+	dw  	256		; cks: directory check vector size - 1024 / 4
 	dw  	0		; off: reserved tracks = 16 trks * (16 trks * 16 heads * 16 secs * 512 bytes) = 128k
 	db	2		; psh: 2 for 512 byte sectors
 	db	3		; phm: (512 / 128) - 1
@@ -253,7 +254,7 @@ dpb$hd:		; 8MB Hard Disk Drive w/ 512 dir entries
 	dw  	512 - 1		; drm: dir entries - 1 = 512 - 1 = 511
 	db  	11110000b	; al0: dir blk bit map, first byte
 	db  	00000000b	; al1: dir blk bit map, second byte
-	dw  	8000h		; cks: directory check vector size - permanent storage = 8000H
+	dw  	8080h		; cks: directory check vector size - permanent storage = 8000H
 	dw  	16		; off: reserved tracks = 16 trks * (16 trks * 16 heads * 16 secs * 512 bytes) = 128k
 	db	2		; psh: 2 for 512 byte sectors
 	db	3		; phm: (512 / 128) - 1
@@ -337,7 +338,7 @@ dpb$hdnew:	; 8MB Hard Disk Drive (new format)
 	dw	1024 - 1	; drm: dir entries
 	db	11111111b	; al0: dir blk bit map, first byte
 	db	00000000b	; al1: dir blk bit map, second byte
-	dw	8000h		; cks: directory check vector size - permanent storage = 8000H
+	dw	8100h		; cks: directory check vector size - permanent storage = 8000H
 	dw	2		; off: reserved tracks
 	db	2		; psh: 2 for 512 byte sectors
 	db	3		; phm: (512 / 128) - 1
diff --git a/Source/ver.inc b/Source/ver.inc
index ffc685e4..86655b37 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,4 +2,4 @@
 #DEFINE	RMN	1
 #DEFINE	RUP	1
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.1.1-pre.6"
+#DEFINE BIOSVER	"3.1.1-pre.7"
diff --git a/Source/ver.lib b/Source/ver.lib
index e55d2ae6..ee5204d5 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	1
 rup	equ	1
 rtp	equ	0
 biosver	macro
-	db	"3.1.1-pre.6"
+	db	"3.1.1-pre.7"
 	endm