From: Jens Guenther 
Date: Wed, 19 Mar 2025 16:56:41 +0100
Subject: [PATCH] Select disk side with bit 3

---
 kernel.mac       | 2 +-
 mbios.mac        | 2 +-
 sysboot.mac      | 2 +-
 utils/format.mac | 6 +++---
 utils/id.mac     | 6 +++---
 5 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/kernel.mac b/kernel.mac
index 2f08fbc..6506fa4 100644
--- a/kernel.mac
+++ b/kernel.mac
@@ -32,7 +32,7 @@ space	equ	' '
 
 #row	equ	24
 #col	equ	80
-#side	equ	4
+#side	equ	3
 
 stack	equ	0fff0h			;upper 16 bytes for wboot !!
 buflen	equ	100			;Length of keyboard buffer
diff --git a/mbios.mac b/mbios.mac
index b588906..c2a0cc7 100644
--- a/mbios.mac
+++ b/mbios.mac
@@ -72,7 +72,7 @@ switch_in	equ	0000_0100b
 switch_out	equ	0000_0101b
 #row		equ	16
 #col		equ	64
-#side		equ	4
+#side		equ	3
 
 	  endif					;zwei_s
 
diff --git a/sysboot.mac b/sysboot.mac
index 7879249..2df7b0d 100644
--- a/sysboot.mac
+++ b/sysboot.mac
@@ -21,7 +21,7 @@
 ;
 loader		equ	0d200h		;Loader address
 max_error	equ	5		;Max # of retries
-#side		equ	0001_0000b
+#side		equ	0000_1000b
 	.phase  4200h			;Boot address (by EPROM)
 
 entry:
diff --git a/utils/format.mac b/utils/format.mac
index 5eeeb1a..325b56c 100644
--- a/utils/format.mac
+++ b/utils/format.mac
@@ -1023,7 +1023,7 @@ hxdz10:
 	ret	nz
 	ld	a,(sel$code)			;front or back ?
 	ld	de,frotxt
-	and	010h
+	and	08h
 	jr	z,prttxt
 	ld	de,bcktxt
 prttxt:
@@ -1042,7 +1042,7 @@ front:
 	ld	a,(s$f1)
 	ld	(low$sector),a
 	ld	a,(sel$code)
-	and	0fh
+	and	07h
 	ld	(sel$code),a
 	ld	a,00h
 	ld	(side$number),a
@@ -1054,7 +1054,7 @@ back_side:
 	ld	a,(s$b1)
 	ld	(low$sector),a
 	ld	a,(sel$code)
-	or	10h
+	or	08h
 	ld	(sel$code),a
 	ld	a,01h
 	ld	(side$number),a
diff --git a/utils/id.mac b/utils/id.mac
index 41e3f7d..915ab61 100644
--- a/utils/id.mac
+++ b/utils/id.mac
@@ -293,14 +293,14 @@ write_cpm:
 ;
 front_side:
 	ld	a,(selcod)
-	and	0fh
+	and	07h
 	ld	(selcod),a
 	ld	a,0
 	ld	(side_number),a
 	ret
 back_side:
 	ld	a,(selcod)
-	or	10h
+	or	08h
 	ld	(selcod),a
 	ld	a,1
 	ld	(side_number),a
@@ -438,7 +438,7 @@ write:
 	cp	10
 	jr	c,write_next
 	ld	a,(selcod)
-	xor	10h				;switch side
+	xor	08h				;switch side
 	ld	(selcod),a
 	xor	a				;restart at sector 0
 write_next:
-- 
2.20.1