Update hbios.asm

Typo + explanation

Source/HBIOS/hbios.asm

@@ -2859,7 +2859,7 @@ SYS_VER:
 ; SET ACTIVE MEMORY BANK AND RETURN PREVIOUSLY ACTIVE MEMORY BANK
 ;   NOTE THAT IT GOES INTO EFFECT AS HBIOS FUNCTION IS EXITED
 ;   HERE, WE JUST SET THE CURRENT BANK
-;   CALLER MUST EXTABLISH UPPER MEMORY STACK BEFORE INVOKING THIS FUNCTION!
+;   CALLER MUST ESTABLISH UPPER MEMORY STACK BEFORE INVOKING THIS FUNCTION!
 ;
 SYS_SETBNK:
 #IF (MEMMGR == MM_Z280)
@@ -3252,8 +3252,8 @@ SYS_PEEK:
 	PUSH	IY
 	HB_DI
   #ELSE
-	LD	A,I
-	DI
+	LD	A,I			; SAVE THE INTERRUPT STATUS
+	DI         			;  COPY IFF2 TO P/V FLAG
 	PUSH	AF
   #ENDIF
 #ENDIF
@@ -3265,8 +3265,8 @@ SYS_PEEK:
 	.DB	$FD,$ED,$6E		; LDCTL	(C),IY
 	POP	IY
   #ELSE
-	POP	AF
-	JP	PO,$+4
+	POP	AF			; RECALL INITIAL INTERRUPT STATUS
+	JP	PO			; RETURN TO INITIAL STATE,$+4
 	HB_EI
   #ENDIF
 #ENDIF
@@ -3289,8 +3289,8 @@ SYS_POKE:
 	PUSH	IY
 	HB_DI
   #ELSE
-	LD	A,I
-	HB_DI
+	LD	A,I			; SAVE THE INTERRUPT STATUS
+	HB_DI      			;  COPY IFF2 TO P/V FLAG
 	PUSH	AF
   #ENDIF
 #ENDIF
@@ -3302,8 +3302,8 @@ SYS_POKE:
 	.DB	$FD,$ED,$6E		; LDCTL	(C),IY
 	POP	IY
   #ELSE
-	POP	AF
-	JP	PO,$+4
+	POP	AF			; RECALL INITIAL INTERRUPT STATUS
+	JP	PO			; RETURN TO INITIAL STATE,$+4
 	HB_EI
   #ENDIF
 #ENDIF