Implement HBIOS Reset Function

Source/CBIOS/cbios.asm

@@ -1844,6 +1844,10 @@ INIT:
 	LD	(8),A			; STORE AT 0x0008
 	LD	HL,($FFF1)		; HBIOS ENTRY VECTOR
 	LD	(9),HL			; STORE AT 0x0009
+	
+	; SOFT REST HBIOS
+	LD	B,BF_SYSRESET		; HB FUNC: RESET
+	RST	08			; DO IT
 
 	; CREATE A TEMP COPY OF THE HBIOS CONFIG BLOCK (HCB)
 	; FOR REFERENCE USE DURING INIT

Source/HBIOS/API.txt

@@ -91,6 +91,9 @@ POKE: ($FA):
   E=Byte Value
   HL=Address
 
+RESET: ($FF):
+  B=Function					A=Result
+
 ================
 Serial Functions
 ================

Source/HBIOS/hbios.asm

@@ -561,6 +561,13 @@ INITSYS1:
 	POP	DE
 	DJNZ	INITSYS1
 ;
+; RECORD HEAP CURB AT THE CURRENT VALUE OF HEAP TOP.  HEAP CURB
+; MARKS THE POINT IN THE HEAP AFTER WHICH MEMORY IS RELEASED
+; WHEN AN HBIOS RESET IS PEFORMED.
+;
+	LD	HL,(HCB + HCB_HEAPTOP)
+	LD	(HEAPCURB),HL
+;
 ; PRIOR TO THIS POINT, CONSOLE I/O WAS DIRECTED TO HARDWARE (XIO.ASM).
 ; NOW THAT HBIOS IS READY, SET THE CONSOLE UNIT TO ACTIVATE CONSOLE I/O
 ; VIA HBIOS.
@@ -1160,6 +1167,16 @@ SYS_DISPATCH:
 	JP	Z,SYS_PEEK	; $F9
 	DEC	A
 	JP	Z,SYS_POKE	; $FA
+	DEC	A
+	;JP	Z,SYS_		; $FB
+	DEC	A
+	;JP	Z,SYS_		; $FC
+	DEC	A
+	;JP	Z,SYS_		; $FD
+	DEC	A
+	;JP	Z,SYS_		; $FE
+	DEC	A
+	JP	Z,SYS_RESET	; $FF
 	CALL	PANIC		; INVALID
 ;
 ; SET ACTIVE MEMORY BANK AND RETURN PREVIOUSLY ACTIVE MEMORY BANK
@@ -1417,6 +1434,14 @@ SYS_POKE:
 	CALL	HBX_POKE	; IMPLEMENTED IN PROXY
 	XOR	A
 	RET
+;
+; SOFT RESET HBIOS, RELEASE HEAP MEMORY NOT USED BY HBIOS
+;
+SYS_RESET:
+	LD	HL,(HEAPCURB)		; GET HBIOS HEAP THRESHOLD
+	LD	(HCB + HCB_HEAPTOP),HL	; RESTORE HEAP TOP
+	XOR	A
+	RET
 ;;
 ;; GET HCB VALUE BYTE
 ;;   C: HCB INDEX (OFFSET INTO HCB)
@@ -2594,6 +2619,8 @@ HSTLBAHI	.EQU	$		; BLOCK ADDRESS LBA HIGH WORD
 HSTSEC		.DB	0		; SECTOR (0-255)
 HSTHEAD		.DB	0		; HEAD (0-255)
 ;
+HEAPCURB	.DW	0		; MARK HEAP ADDRESS AFTER INITIALIZATION
+;
 HB_INTSTKSAV	.DW	0		; SAVED STACK POINTER DURING INT PROCESSING
 		.FILL	$40,$FF		; 32 ENTRY STACK FOR INTERRUPT PROCESSING
 HB_INTSTK	.EQU	$		; TOP OF INTERRUPT PROCESSING STACK

Source/HBIOS/hbios.inc

@@ -62,8 +62,9 @@ BF_SYSFREE	.EQU	BF_SYS + 5	; FREE HBIOS HEAP MEMORY
 BF_SYSVER	.EQU	BF_SYS + 6	; GET HBIOS VERSION
 BF_SYSGET	.EQU	BF_SYS + 7	; GET HBIOS INFO
 BF_SYSSET	.EQU	BF_SYS + 8	; SET HBIOS PARAMETERS
-BF_PEEK		.EQU	BF_SYS + 9	; GET A BYTE VALUE FROM ALT BANK
-BF_POKE		.EQU	BF_SYS + 10	; SET A BYTE VALUE IN ALT BANK
+BF_SYSPEEK	.EQU	BF_SYS + 9	; GET A BYTE VALUE FROM ALT BANK
+BF_SYSPOKE	.EQU	BF_SYS + 10	; SET A BYTE VALUE IN ALT BANK
+BF_SYSRESET	.EQU	BF_SYS + 15	; SOFT RESET HBIOS
 ;
 BF_SYSGET_CIOCNT	.EQU	$00	; GET CHAR UNIT COUNT
 BF_SYSGET_DIOCNT	.EQU	$10	; GET DISK UNIT COUNT