Interrupt framework implementation

- Interrupt framework
- Documentation in progress w/ Latex conversion

Source/CBIOS/cbios.asm

@@ -283,8 +283,8 @@ DPBCNT	.EQU	($ - DPBMAP) / 2
 ;__________________________________________________________________________________________________
 BOOT:
 	; STANDARD BOOT INVOCATION
-	DI
-	IM	1
+	;DI
+	;IM	1
 	LD	SP,STACK	; STACK FOR INITIALIZATION
 ;
 	CALL	INIT		; EXECUTE COLD BOOT ROUTINE
@@ -301,11 +301,13 @@ BOOT:
 REBOOT:
 	; REBOOT FROM ROM, REPLACES BOOT AFTER INIT
 #IFDEF PLTUNA
+	DI				; NO INTERRUPTS
 	LD	BC,$01FB		; UNA FUNC = SET BANK
 	LD	DE,0			; ROM BOOT BANK
 	CALL	$FFFD			; DO IT (RST 08 NOT SAFE HERE)
 #ENDIF
 #IFDEF PLTWBW
+	DI				; NO INTERRUPTS
 	LD	A,0			; ROM BOOT BANK
 	CALL	HB_BNKSEL		; SELECT IT INTO LOW MEMORY
 #ENDIF
@@ -315,8 +317,8 @@ REBOOT:
 ;
 ;__________________________________________________________________________________________________
 WBOOT:
-	DI
-	IM	1
+	;DI
+	;IM	1
 ;
 	LD	SP,STACK	; STACK FOR INITIALIZATION
 ;
@@ -1083,7 +1085,6 @@ BLK_BLOCK:
 	LDIR
 	RET
 #ELSE
-	;LD	B,BF_SYSXCPY	; HBIOS FUNC: SYSTEM EXTENDED COPY
 	LD	B,BF_SYSSETCPY	; HBIOS FUNC: SETUP BANK COPY
 	LD	A,(BNKUSER)	; GET USER BANK
 	LD	E,A		; E = SOURCE (USER BANK)
@@ -1092,13 +1093,9 @@ BLK_BLOCK:
 	LD	HL,128		; HL = COPY LEN = DMA BUFFER SIZE
 	RST	08		; DO IT
 	CALL	BLK_SETUP	; SETUP SOURCE AND DESTINATION
-	;LD	B,BF_SYSCPY	; HBIOS FUNC: SYSTEM COPY
 	LD	B,BF_SYSBNKCPY	; HBIOS FUNC: PERFORM BANK COPY
 	EX	DE,HL		; SWAP HL/DE FOR BLOCK OPERATION
-	;PUSH	IX		; SAVE IX
-	;LD	IX,128		; DMA BUFFER SIZE
 	RST	08		; DO IT
-	;POP	IX		; RESTORE IX
 	RET
 #ENDIF
 ;
@@ -1113,18 +1110,13 @@ BLK_DEBLOCK:
 	LDIR
 	RET
 #ELSE
-	;LD	B,BF_SYSXCPY	; HBIOS FUNC: SYSTEM EXTENDED COPY
 	LD	B,BF_SYSSETCPY	; HBIOS FUNC: SETUP BANK COPY
 	LD	DE,(BNKBIOS)	; E = SOURCE (BIOS BANK), D = DEST (USER BANK)
 	LD	HL,128		; HL = COPY LEN = DMA BUFFER SIZE
 	RST	08		; DO IT
 	CALL	BLK_SETUP	; SETUP SOURCE AND DESTINATION
-	;LD	B,BF_SYSCPY	; HBIOS FUNC: SYSTEM COPY
 	LD	B,BF_SYSBNKCPY	; HBIOS FUNC: PERFORM BANK COPY
-	;PUSH	IX		; SAVE IX
-	;LD	IX,128		; DMA BUFFER SIZE
 	RST	08		; DO IT
-	;POP	IX		; RESTORE IX
 	RET
 #ENDIF
 ;
@@ -1809,6 +1801,8 @@ HEAPEND	.EQU	CBIOS_END - 64		; TOP OF HEAP MEM, END OF CBIOS LESS 32 ENTRY STACK
 	.FILL	16 * 16,0		; SKIP DPH TABLE AREA
 ;
 INIT:
+	DI				; NO INTERRUPTS FOR NOW
+
 	; ADJUST BOOT VECTOR TO REBOOT ROUTINE
 	LD	HL,REBOOT		; GET REBOOT ADDRESS
 	LD	(CBIOS_LOC + 1),HL	; STORE IT IN FIRST ENTRY OF CBIOS JUMP TABLE
@@ -1819,50 +1813,56 @@ INIT:
 	LD	DE,BID_USR		; SWITCH BACK TO EXEC BANK
 	CALL	$FFFD			; DO IT (RST 08 NOT YET INSTALLED)
 
+	; COPY BIOS PAGE ZERO TO USER BANK
+	LD	BC,$01FB		; UNA FUNC = SET BANK
+	LD	DE,BID_BIOS		; UBIOS_PAGE (SEE PAGES.INC)
+	CALL	$FFFD			; DO IT (RST 08 NOT YET INSTALLED)
+	PUSH	DE			; SAVE PREVIOUS BANK
+	
+	LD	HL,0			; FROM ADDRESS 0 (PAGE ZERO)
+	LD	DE,SECBUF		; USE SECBUF AS BOUNCE BUFFER
+	LD	BC,256			; ONE PAGE IS 256 BYTES
+	LDIR				; DO IT
+	
+	LD	BC,$01FB		; UNA FUNC = SET BANK
+	POP	DE			; RECOVER OPERATING BANK
+	CALL	$FFFD			; DO IT (RST 08 NOT YET INSTALLED)
+
+	LD	HL,SECBUF		; FROM SECBUF (BUNCE BUFFER)
+	LD	DE,0			; TO PAGE ZERO OF OPERATING BANK
+	LD	BC,256			; ONE PAGE IS 256 BYTES
+	LDIR				; DO IT
+	
 	; INSTALL UNA INVOCATION VECTOR FOR RST 08
 	LD	A,$C3			; JP INSTRUCTION
 	LD	(8),A			; STORE AT 0x0008
 	LD	HL,($FFFE)		; UNA ENTRY VECTOR
 	LD	(9),HL			; STORE AT 0x0009
 #ELSE
+	; GET CRITICAL BANK ID'S
 	LD	B,BF_SYSGET		; HBIOS FUNC=GET SYS INFO
 	LD	C,BF_SYSGET_BNKINFO	; HBIOS SUBFUNC=GET BANK ASSIGNMENTS
-	CALL	$FFF0			; CALL HBIOS, RST 08 NOT YET INSTALLED
+	RST	08			; CALL HBIOS
 	LD	A,D			; GET HBIOS BANK RETURNED IN D
 	LD	(BNKBIOS),A		; ... AND SAVE IT
 	LD	A,E			; GET USER BANK RETURNED IN E
 	LD	(BNKUSER),A		; ... AND SAVE IT
 
-	; MAKE SURE USER BANK IS ACTIVE
-	LD	B,BF_SYSSETBNK		; HB FUNC: SET BANK
-	LD	A,(BNKUSER)		; SELECT USER BANK
-	LD	C,A			; PUT IN C
-	CALL	$FFF0			; RST 8 IS NOT YET INSTALLED
-	
-	; INSTALL HBIOS INVOCATION VECTOR FOR RST 08
-	LD	A,$C3			; JP INSTRUCTION
-	LD	(8),A			; STORE AT 0x0008
-	LD	HL,($FFF1)		; HBIOS ENTRY VECTOR
-	LD	(9),HL			; STORE AT 0x0009
-	
-	; SOFT REST HBIOS
+	; SOFT RESET 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
-	;LD	B,BF_SYSXCPY		; HBIOS FUNC: SYSTEM EXTENDED COPY
 	LD	B,BF_SYSSETCPY		; HBIOS FUNC: SETUP BANK COPY
 	LD	DE,(BNKBIOS)		; D = DEST (USER BANK), E = SOURCE (BIOS BANK)
 	LD	HL,HCB_SIZ		; HL = COPY LEN = SIZE OF HCB
 	RST	08			; DO IT
-	;LD	B,BF_SYSCPY		; HBIOS FUNC: SYSTEM COPY
 	LD	B,BF_SYSBNKCPY		; HBIOS FUNC: PERFORM BANK COPY
 	LD	HL,HCB_LOC		; COPY FROM FIXED LOCATION IN HB BANK
 	LD	DE,HCB			; TO TEMP LOCATION IN USR BANK
-	;LD	IX,HCB_SIZ		; COPY CONTENTS OF HCB
 	RST	08			; DO IT
-
+	
 	; CAPTURE RAM DRIVE STARTING BANK
 	LD	A,(HCB + HCB_BIDRAMD0)
 	LD	(BNKRAMD),A
@@ -2131,6 +2131,7 @@ MD_INIT4:
 ; FILL FIRST 8K OF RAM DISK TRACK 1 WITH 'E5'
 ;
 #IF (CLRRAMDISK != CLR_NEVER)
+	DI				; NO INTERRUPTS
 	LD	BC,$01FB		; UNA FUNC = SET BANK
 	LD	DE,BID_RAMD0		; FIRST BANK OF RAM DISK
 	CALL	$FFFD			; DO IT (RST 08 NOT SAFE HERE)
@@ -2176,6 +2177,7 @@ CLRRAM3:
 	LD	BC,$01FB		; UNA FUNC = SET BANK
 	LD	DE,BID_USR		; SWITCH BACK TO EXEC BANK
 	CALL	$FFFD			; DO IT (RST 08 NOT SAFE HERE)
+	EI				; RESUME INTERRUPTS
 
 #ENDIF
 
@@ -2185,10 +2187,9 @@ CLRRAM3:
 ; FILL FIRST 8K OF RAM DISK TRACK 1 WITH 'E5'
 ;
 #IF (CLRRAMDISK != CLR_NEVER)
-	LD	B,BF_SYSSETBNK		; HBIOS FUNC: SET BANK
+	DI				; NO INTERRUPTS
 	LD	A,(BNKRAMD)		; FIRST BANK OF RAM DISK
-	LD	C,A			; ... TO C
-	CALL	$FFF0			; DO IT (RST 08 NOT SAFE)
+	CALL	HB_BNKSEL		; SELECT BANK
 
 #IF (CLRRAMDISK == CLR_AUTO)
 	; CHECK FIRST 32 DIRECTORY ENTRIES.  IF ANY START WITH AN INVALID
@@ -2211,26 +2212,21 @@ CLRRAM1:
 	JR	CLRRAM3			; ALL ENTRIES VALID, BYPASS INIT
 CLRRAM2:
 #ENDIF
-	LD	B,BF_SYSSETBNK		; HBIOS FUNC: SET BANK
 	LD	A,(BNKUSER)		; SWITCH BACK TO USER BANK
-	LD	C,A			; ... TO REG C
-	CALL	$FFF0			; DO IT (RST 08 NOT SAFE)
+	CALL	HB_BNKSEL		; SELECT BANK
 	CALL	NEWLINE2		; FORMATTING
 	LD	DE,STR_INITRAMDISK	; RAM DISK INIT MESSAGE
 	CALL	WRITESTR		; DISPLAY IT
-	LD	B,BF_SYSSETBNK		; HBIOS FUNC: SET BANK
 	LD	A,(BNKRAMD)		; SWITCH BACK TO FIRST BANK
-	LD	C,A			; ... TO REG C
-	CALL	$FFF0			; DO IT (RST 08 NOT SAFE)
+	CALL	HB_BNKSEL		; SELECT BANK
 	LD	HL,0			; SOURCE ADR FOR FILL
 	LD	BC,$2000		; LENGTH OF FILL IS 8K
 	LD	A,$E5			; FILL VALUE
 	CALL	FILL			; DO IT
 CLRRAM3:
-	LD	B,BF_SYSSETBNK		; HBIOS FUNC: SET BANK
 	LD	A,(BNKUSER)		; USR BANK (TPA)
-	LD	C,A			; ... TO REG C
-	CALL	$FFF0			; DO IT (RST 08 NOT SAFE)
+	CALL	HB_BNKSEL		; SELECT BANK
+	EI				; RESUME INTRRUPTS
 #ENDIF
 ;
 #ENDIF

Source/HBIOS/Config/plt_mk4.asm

@@ -8,6 +8,7 @@
 CPUOSC		.EQU	18432000	; CPU OSC FREQ
 RAMSIZE		.EQU	512		; SIZE OF RAM IN KB, MUST MATCH YOUR HARDWARE!!!
 DEFSERCFG	.EQU	SER_38400_8N1	; DEFAULT SERIAL LINE CONFIG (SHOULD MATCH ABOVE)
+INTTYPE		.EQU	IT_Z180		; INTERRUPT HANDLING TYPE (IT_NONE, IT_SIMH, IT_Z180, IT_CTC, ...)
 ;
 CRTACT		.EQU	FALSE		; CRT ACTIVATION AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; DEFAULT VDA EMULATION (EMUTYP_TTY, EMUTYP_ANSI, ...)

Source/HBIOS/Config/plt_n8.asm

@@ -8,6 +8,7 @@
 CPUOSC		.EQU	18432000	; CPU OSC FREQ
 RAMSIZE		.EQU	512		; SIZE OF RAM IN KB, MUST MATCH YOUR HARDWARE!!!
 DEFSERCFG	.EQU	SER_38400_8N1	; DEFAULT SERIAL LINE CONFIG (SHOULD MATCH ABOVE)
+INTTYPE		.EQU	IT_Z180		; INTERRUPT HANDLING TYPE (IT_NONE, IT_SIMH, IT_Z180, IT_CTC, ...)
 ;
 CRTACT		.EQU	FALSE		; CRT ACTIVATION AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; DEFAULT VDA EMULATION (EMUTYP_TTY, EMUTYP_ANSI, ...)

Source/HBIOS/Config/plt_sbc.asm

@@ -8,6 +8,7 @@
 CPUOSC		.EQU	8000000		; CPU OSC FREQ
 RAMSIZE		.EQU	512		; SIZE OF RAM IN KB, MUST MATCH YOUR HARDWARE!!!
 DEFSERCFG	.EQU	SER_38400_8N1	; DEFAULT SERIAL LINE CONFIG (SHOULD MATCH ABOVE)
+INTTYPE		.EQU	IT_NONE		; INTERRUPT HANDLING TYPE (IT_NONE, IT_SIMH, IT_Z180, IT_CTC, ...)
 ;
 CRTACT		.EQU	FALSE		; CRT ACTIVATION AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; DEFAULT VDA EMULATION (EMUTYP_TTY, EMUTYP_ANSI, ...)

Source/HBIOS/Config/plt_zeta.asm

@@ -8,6 +8,7 @@
 CPUOSC		.EQU	20000000	; CPU OSC FREQ
 RAMSIZE		.EQU	512		; SIZE OF RAM IN KB, MUST MATCH YOUR HARDWARE!!!
 DEFSERCFG	.EQU	SER_38400_8N1	; DEFAULT SERIAL LINE CONFIG (SHOULD MATCH ABOVE)
+INTTYPE		.EQU	IT_NONE		; INTERRUPT HANDLING TYPE (IT_NONE, IT_SIMH, IT_Z180, IT_CTC, ...)
 ;
 CRTACT		.EQU	FALSE		; CRT ACTIVATION AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; DEFAULT VDA EMULATION (EMUTYP_TTY, EMUTYP_ANSI, ...)

Source/HBIOS/Config/plt_zeta2.asm

@@ -7,4 +7,6 @@
 ;
 #INCLUDE "Config/plt_zeta.asm"		; USE ZETA CONFIG TO START
 ;
+INTTYPE		.SET	IT_CTC		; INTERRUPT HANDLING TYPE (IT_NONE, IT_SIMH, IT_Z180, IT_CTC, ...)
+;
 FDMODE		.SET	FDMODE_ZETA2	; FDMODE_DIO, FDMODE_ZETA, FDMODE_DIDE, FDMODE_N8, FDMODE_DIO3

Source/HBIOS/Config/sbc_simh.asm

@@ -5,6 +5,8 @@
 ;
 CPUOSC		.SET	20000000	; EMULATOR RUNS FAST...
 ;
+INTTYPE		.SET	IT_SIMH
+;
 SIMRTCENABLE	.SET	TRUE
 DSRTCENABLE	.SET	FALSE
 ;

Source/HBIOS/asci.asm

@@ -428,7 +428,7 @@ ASCI_CNTLB:
 	;CALL	TSTPT
 	RET	NZ			; ABORT ON ERROR
 	PUSH	HL			; HL HAS (BAUD / 75), SAVE IT
-	LD	HL,(HCB + HCB_CPUKHZ)	; GET CPU CLK IN KHZ
+	LD	HL,(CB_CPUKHZ)		; GET CPU CLK IN KHZ
 	;LD	HL,CPUKHZ		; CPU CLK IN KHZ
 	;LD	HL,9216			; *DEBUG*
 	

Source/HBIOS/dsrtc.asm

@@ -182,7 +182,7 @@ DSRTC_GETTIM:
 	LD	HL,DSRTC_TIMBUF		; SOURCE ADR
 	POP	DE			; DEST ADR
 	LD	BC,6			; LENGTH IS 6 BYTES
-	CALL	BNKCPY			; COPY THE CLOCK DATA
+	CALL	HBX_BNKCPY		; COPY THE CLOCK DATA
 ;
 	; CLEAN UP AND RETURN
 	XOR	A			; SIGNAL SUCCESS
@@ -207,7 +207,7 @@ DSRTC_SETTIM:
 	LD	(HB_DSTBNK),A		; SET IT
 	LD	DE,DSRTC_TIMBUF		; DEST ADR
 	LD	BC,6			; LENGTH IS 6 BYTES
-	CALL	BNKCPY			; COPY THE CLOCK DATA
+	CALL	HBX_BNKCPY		; COPY THE CLOCK DATA
 ;
 	; WRITE TO CLOCK
 	LD	HL,DSRTC_TIMBUF		; POINT TO TIME BUFFER

Source/HBIOS/hbios.asm

@@ -49,6 +49,7 @@
 #INCLUDE "std.asm"
 ;
 ; MAKE SURE EXACTLY ONE OF ROMBOOT, APPBOOT, IMGBOOT IS DEFINED.
+;
 MODCNT	.EQU	0
 #IFDEF ROMBOOT
 MODCNT	.SET	MODCNT + 1
@@ -65,19 +66,28 @@ MODCNT	.SET	MODCNT + 1
 #ENDIF
 ;
 ;
+;
+#IF (INTTYPE != IT_NONE)
+#DEFINE	HB_EI	EI
+#DEFINE	HB_DI	DI
+#ELSE
+#DEFINE	HB_EI	;
+#DEFINE	HB_DI	;
+#ENDIF
+;
 #IFNDEF	APPBOOT
 ;
 	.ORG	0
 ;
 ;==================================================================================================
-; NORMAL PAGE ZERO SETUP, RET/RETI/RETN AS APPROPRIATE
+; NORMAL PAGE ZERO SETUP, RET/RETI/RETN AS APPROPRIATE, LEAVE INTERRUPTS DISABLED
 ;==================================================================================================
 ;
 	.FILL	(000H - $),0FFH		; RST 0
 	JP	HB_START
 	.DW	ROM_SIG
 	.FILL	(008H - $),0FFH		; RST 8
-	JP	HB_DISPATCH
+	JP	HBX_INVOKE		; INVOKE HBIOS FUNCTION
 	.FILL	(010H - $),0FFH		; RST 10
 	RET
 	.FILL	(018H - $),0FFH		; RST 18
@@ -88,7 +98,7 @@ MODCNT	.SET	MODCNT + 1
 	RET
 	.FILL	(030H - $),0FFH		; RST 30
 	RET
-	.FILL	(038H - $),0FFH		; INT
+	.FILL	(038H - $),0FFH		; RST 38 / INT
 	RETI
 	.FILL	(066H - $),0FFH		; NMI
 	RETN
@@ -106,7 +116,7 @@ ROM_SIG:
 ;
 NAME	.DB	"ROMWBW v", BIOSVER, ", ", TIMESTAMP, 0
 AUTH	.DB	"WBW",0
-DESC	.DB	"ROMWBW v", BIOSVER, ", Copyright 2015, Wayne Warthen, GNU GPL v3", 0
+DESC	.DB	"ROMWBW v", BIOSVER, ", Copyright (C) 2015, Wayne Warthen, GNU GPL v3", 0
 ;
 	.FILL	($100 - $),$FF		; PAD REMAINDER OF PAGE ZERO
 ;
@@ -171,18 +181,16 @@ CB_BIDROMDN	.DB	BID_ROMDN
 	.ORG	HBX_LOC		; ADJUST FOR RELOCATION
 ;
 ; MEMORY LAYOUT:
+;
 ;   HBIOS PROXY CODE		$FE00 (256 BYTES)
 ;   INTERRUPT VECTORS		$FF00 (32 BYTES, 16 ENTRIES)
-;   HBIOS PROXY COPY BUFFER	$FF20 (128 BYTES)
-;   HBIOS PROXY PRIVATE STACK	$FFA0 (64 BYTES, 32 ENTRIES)
+;   INTERRUPT HANDLER STUBS	$FF20 (128 BYTES)
+;   HBIOS PROXY COPY BUFFER	$FF80 (64 BYTES)
 ;   HBIOS PROXY MGMT BLOCK	$FFE0 (32 BYTES)
 ;
 ; DEFINITIONS
 ;
-HBX_CODSIZ	.EQU	$100	; 256 BYTE CODE SPACE
-HBX_IVTSIZ	.EQU	$20	; INT VECTOR TABLE SIZE (16 ENTRIES)
-HBX_BUFSIZ	.EQU	$80	; INTERBANK COPY BUFFER
-HBX_STKSIZ	.EQU	$40	; PRIVATE STACK SIZE
+HBX_BUFSIZ	.EQU	$40	; INTERBANK COPY BUFFER
 ;
 ; HBIOS IDENTIFICATION DATA BLOCK
 ;
@@ -197,24 +205,28 @@ HBX_IDENT:
 ;
 HBX_INVOKE:
 	LD	(HBX_STKSAV),SP	; SAVE ORIGINAL STACK FRAME
-	LD	SP,HBX_STACK	; SETUP NEW STACK FRAME
-
 	LD	A,(HB_CURBNK)	; GET CURRENT BANK
 	LD	(HBX_INVBNK),A	; SETUP TO RESTORE AT EXIT
 
+	HB_DI
+	LD	SP,HBX_STACK	; USE STACK FRAME IN HI MEM
 	LD	A,BID_BIOS	; HBIOS BANK
 	CALL	HBX_BNKSEL	; SELECT IT
+	LD	SP,HB_STACK	; NOW USE FULL HBIOS STACK IN HBIOS BANK
+	HB_EI
 
 	CALL	HB_DISPATCH	; CALL HBIOS FUNCTION DISPATCHER
 
+	HB_DI
+	LD	SP,HBX_STACK	; USE STACK FRAME IN HI MEM
 	PUSH	AF		; SAVE AF (FUNCTION RETURN)
 	LD	A,$FF		; LOAD ORIGINAL BANK ($FF IS REPLACED AT ENTRY)
 HBX_INVBNK	.EQU	$ - 1
 	CALL	HBX_BNKSEL	; SELECT IT
 	POP	AF		; RESTORE AF
-
 	LD	SP,0		; RESTORE ORIGINAL STACK FRAME
 HBX_STKSAV	.EQU	$ - 2
+	HB_EI
 
 	RET			; RETURN TO CALLER
 ;
@@ -222,11 +234,14 @@ HBX_STKSAV	.EQU	$ - 2
 ;; SETBNK - Switch Memory Bank to Bank in A.
 ;;   Preserve all Registers including Flags.
 ;;   Does NOT update current bank.
+;;   Interrupts should be disabled by caller
 ;;::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 ;
 HBX_BNKSEL:
 	LD	(HB_CURBNK),A		; RECORD NEW CURRENT BANK
 ;
+HBX_BNKSEL_INT:
+;
 #IF ((PLATFORM == PLT_SBC) | (PLATFORM == PLT_ZETA))
 	OUT	(MPCL_ROM),A		; SET ROM PAGE SELECTOR
 	OUT	(MPCL_RAM),A		; SET RAM PAGE SELECTOR
@@ -294,6 +309,10 @@ HBX_BNKSEL1:
 ;::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 ;
 HBX_BNKCPY:
+	HB_DI
+	LD	(HBX_BC_SP),SP
+	LD	SP,HBX_STACK
+
 	LD	A,(HB_CURBNK)	; GET CURRENT BANK
 	PUSH	AF		; AND SAVE TO RESTORE LATER
 	PUSH	BC		; CUR LEN -> (SP)
@@ -316,7 +335,11 @@ HBX_BC_LAST:
 	POP	BC		; BC := REM LEN
 	CALL	NZ,HBX_BC_ITER	; DO FINAL CHUNK, BUT ONLY IF NOT ZERO BYTES
 	POP	AF		; RECOVER ORIGINAL BANK
-	JP	HBX_BNKSEL	; SWITCH TO CURRENT BANK AND EXIT
+	CALL	HBX_BNKSEL	; SWITCH TO CURRENT BANK AND EXIT
+	LD	SP,$FFFF
+HBX_BC_SP	.EQU	$ - 2
+	HB_EI
+	RET
 ;
 HBX_BC_ITER:
 	; HL = SRC ADR, DE = DEST ADR, BC = LEN
@@ -342,6 +365,7 @@ HBX_BC_ITER:
 ; On input A=target bank, HL=target address
 ;
 HBX_BNKCALL:
+	HB_DI
 	LD	(HBX_TGTBNK),A	; stuff target bank to call into code below
 	LD	(HBX_TGTADR),HL	; stuff address to call into code below
 	LD	A,(HB_CURBNK)	; get current bank
@@ -349,17 +373,82 @@ HBX_BNKCALL:
 HBX_TGTBNK	.EQU	$ + 1
 	LD	A,$FF		; load bank to call ($FF overlaid at entry)
 	CALL	HBX_BNKSEL	; activate the new bank
+	HB_EI
+
 HBX_TGTADR	.EQU	$ + 1
 	CALL	$FFFF		; call routine ($FFFF is overlaid above)
+
+	HB_DI
 	EX	(SP),HL		; save hl and get bank to restore in hl
 	PUSH	AF		; save af
 	LD	A,H		; bank to restore to a
 	CALL	HBX_BNKSEL	; restore it
 	POP	AF		; recover af
 	POP	HL		; recover hl
+	HB_EI
 	RET
 ;
-; INTERRUPT HANDLER DISPATCHING
+; PEEK & POKE ROUTINES
+;   ADDRESS IN HL, BANK IN D, VALUE IN/OUT IN E, A IS TRASHED
+;
+HBX_PEEK:
+	HB_DI
+	LD	A,(HB_CURBNK)
+	PUSH	AF
+	LD	A,D	
+	CALL	HBX_BNKSEL
+	LD	E,(HL)
+	JR	HBX_PPRET
+;
+HBX_POKE:
+	HB_DI
+	LD	A,(HB_CURBNK)
+	PUSH	AF
+	LD	A,D	
+	CALL	HBX_BNKSEL
+	LD	(HL),E
+;
+HBX_PPRET:
+	POP	AF
+	CALL	HBX_BNKSEL
+	HB_EI
+	RET
+;
+; PRIVATE STACK AT END OF HBIOS CODE
+; OCCUPIES SPACE BEFORE IVT
+;
+HBX_STKSIZ	.EQU	$FF00 - $
+		.ECHO	"HBIOS STACK space: "
+		.ECHO	HBX_STKSIZ
+		.ECHO	" bytes.\n"
+		.FILL	HBX_STKSIZ,$FF
+HBX_STACK	.EQU	$
+;
+; HBIOS INTERRUPT VECTOR TABLE (16 ENTRIES)
+;
+HBX_IVT:
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+		.DW	INT_BAD
+;
+; INTERRUPT HANDLER STUBS
+;
+; THE FOLLOWING INTERRUPT STUBS RECEIVE CONTROL FROM THE
+; INTERRUPT, SETUP A HANDLER VECTOR IN HBIOS AND THEN
+; BRANCH TO THE COMMON INTERRUPT DISPATCHER
 ;
 INT_TIMER:	; TIMER INTERRUPT HANDLER
 	PUSH	HL				; SAVE HL
@@ -377,159 +466,49 @@ INT_BAD:	; BAD INTERRUPT HANDLER
 HBX_INT:	; COMMON INTERRUPT ROUTING CODE
 ;
 	; SAVE STATE (ASSUMES HL SAVED PREVIOUSLY)
-	PUSH	AF				; SAVE AF
-	PUSH	BC				; SAVE BC
-	PUSH	DE				; SAVE DE
+	PUSH	AF			; SAVE AF
+	PUSH	BC			; SAVE BC
+	PUSH	DE			; SAVE DE
 
-	; ACTIVATE BIOS BANK
-#IF ((PLATFORM == PLT_SBC) | (PLATFORM == PLT_ZETA))
-	LD	A,BID_BIOS			; BIOS PAGE INDEX TO ACCUM
-	OUT	(MPCL_ROM),A			; SET ROM PAGE SELECTOR
-	OUT	(MPCL_RAM),A			; SET RAM PAGE SELECTOR
-#ENDIF
-#IF (PLATFORM == PLT_ZETA2)
-	LD	A,(BID_BIOS - $80 + $10) * 2	; BIOS BID -> PAGE INDEX -> A
-	OUT	(MPGSEL_0),A			; BANK_0: 0K - 16K
-	INC	A				;
-	OUT	(MPGSEL_1),A			; BANK_1: 16K - 32K
-#ENDIF
-#IF (PLATFORM == PLT_N8)
-	LD	A,(BID_BIOS << 3) & $FF		; BIOS BID -> BBR VAL -> A
-	OUT0	(Z180_BBR),A			; WRITE TO Z180 BANK BASE REG
-	LD	A,N8_DEFACR | $80		; BIT 7 SET FOR RAM
-	OUT0	(N8_ACR),A			; WRITE TO N8 ACR
-#ENDIF
-#IF (PLATFORM == PLT_MK4)
-	LD	A,(BID_BIOS << 3) & $FF | $80	; BIOS BID -> PAGE INDEX -> A
-	OUT0	(Z180_BBR),A			; WRITE TO Z180 BANK BASE REG
-#ENDIF
+	LD	(HBX_INT_SP),SP		; SAVE ORIGINAL STACK FRAME
+	LD	SP,HBX_STACK		; USE STACK FRAME IN HI MEM
+	
+	LD	A,BID_BIOS		; HBIOS BANK
+	CALL	HBX_BNKSEL_INT		; SELECT IT
 
-	; SETUP INTERRUPT PROCESSING STACK IN HBIOS
-	LD	(HB_INTSTKSAV),SP		; SAVE STACK POINTER
-	LD	SP,HB_INTSTK			; SWITCH TO INTERRUPT STACK
+	LD	SP,HB_ISTACK		; NOW USE INT STACK IN HBIOS BANK
 
-	; DO THE REAL WORK
-	CALL	JPHL				; CALL INTERRUPT ROUTINE
+	CALL	JPHL			; CALL INTERRUPT ROUTINE
 
-	; RESTORE STACK
-	LD	SP,(HB_INTSTKSAV)		; RESTORE STACK
+	LD	SP,HBX_STACK		; USE STACK FRAME IN HI MEM
+
+	LD	A,(HB_CURBNK)		; GET PRE-INT BANK
+	CALL	HBX_BNKSEL		; SELECT IT
+
+	LD	SP,$FFFF		; RESTORE ORIGINAL STACK FRAME
+HBX_INT_SP	.EQU	$ - 2
 
-	; RESTORE BANK
-	LD	A,(HB_CURBNK)			; GET PRE-INT BANK
-;
-#IF ((PLATFORM == PLT_SBC) | (PLATFORM == PLT_ZETA))
-	OUT	(MPCL_ROM),A		; SET ROM PAGE SELECTOR
-	OUT	(MPCL_RAM),A		; SET RAM PAGE SELECTOR
-#ENDIF
-#IF (PLATFORM == PLT_ZETA2)
-	BIT	7,A			; BIT 7 SET REQUESTS RAM PAGE
-	JR	Z,HBX_INT1		; NOT SET, SELECT ROM PAGE
-	RES	7,A			; RAM PAGE REQUESTED: CLEAR ROM BIT
-	ADD	A,16			; ADD 16 x 32K - RAM STARTS FROM 512K 
-;
-HBX_INT1:
-	RLCA				; TIMES 2 - GET 16K PAGE INSTEAD OF 32K
-	OUT	(MPGSEL_0),A		; BANK_0: 0K - 16K
-	INC	A			;
-	OUT	(MPGSEL_1),A		; BANK_1: 16K - 32K
-#ENDIF
-#IF (PLATFORM == PLT_N8)
-	BIT	7,A			; TEST BIT 7 FOR RAM VS. ROM
-	JR	Z,HBX_INT1		; IF NOT SET, SELECT ROM PAGE
-;
-	RES	7,A			; CLEAR BIT 7 FOR RAM VS. ROM
-	RLCA				; SCALE SELECTOR TO
-	RLCA				; ... GO FROM Z180 4K PAGE SIZE
-	RLCA				; ... TO DESIRED 32K PAGE SIZE
-	OUT0	(Z180_BBR),A		; WRITE TO BANK BASE
-	JR	HBX_INT2		; CONTINUE
-;
-HBX_INT1:	; SELECT ROM PAGE
-	XOR	A			; ZERO ACCUM
-	OUT0	(Z180_BBR),A		; ZERO BANK BASE
-	LD	A,N8_DEFACR		; SELECT ROM  BY CLEARING BIT 7
-	OUT0	(N8_ACR),A		; ... IN N8 ACR REGISTER
-;
-HBX_INT2:
-#ENDIF
-#IF (PLATFORM == PLT_MK4)
-	RLCA				; RAM FLAG TO CARRY AND BIT 0
-	JR	NC,HBX_INT1		; IF NC, ROM, SKIP AHEAD
-	XOR	%00100001		; SET BIT FOR HI 512K, CLR BIT 0
-HBX_INT1:
-	RLCA				; ROTATE
-	RLCA				; ... AGAIN
-	OUT0	(Z180_BBR),A		; WRITE TO BANK REGISTER
-#ENDIF
-;
 	; RESTORE STATE
 	POP	DE			; RESTORE DE
 	POP	BC			; RESTORE BC
 	POP	AF			; RESTORE AF
 	POP	HL			; RESTORE HL
 
-	; DONE
-	RETI			; IMPLICITLY REENABLES INTERRUPTS!
+	EI				; ENABLE INTERRUPTS
+	RETI				; AND RETURN
 ;
-; PEEK & POKE ROUTINES
-;   ADDRESS IN HL, BANK IN D, VALUE IN/OUT IN E, A IS TRASHED
+; FILL TO START OF BOUNCE BUFFER
 ;
-HBX_PEEK:
-	LD	A,(HB_CURBNK)
-	PUSH	AF
-	LD	A,D	
-	CALL	HBX_BNKSEL
-	LD	E,(HL)
-	POP	AF
-	JP	HBX_BNKSEL
-;
-HBX_POKE:
-	LD	A,(HB_CURBNK)
-	PUSH	AF
-	LD	A,D	
-	CALL	HBX_BNKSEL
-	LD	(HL),E
-	POP	AF
-	JP	HBX_BNKSEL
-;
-; FILLER FOR UNUSED HBIOS PROXY CODE SPACE
-; PAD TO START OF INTERRUPT VECTOR TABLE
-;
-HBX_SLACK	.EQU	(HBX_LOC + HBX_CODSIZ - $)
-		.ECHO	"HBIOS PROXY space remaining: "
-		.ECHO	HBX_SLACK
+HBX_INTFILL	.EQU	(HBX_XFC - HBX_BUFSIZ - $)
+		.ECHO	"HBIOS INT space remaining: "
+		.ECHO	HBX_INTFILL
 		.ECHO	" bytes.\n"
-		.FILL	HBX_SLACK,$FF
+		.FILL	HBX_INTFILL,$FF
 ;
-; HBIOS INTERRUPT VECTOR TABLE (16 ENTRIES)
-;
-HBX_IVT:
-		.DW	INT_TIMER
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-		.DW	INT_BAD
-;
-; INTERBANK COPY BUFFER (128 BYTES)
+; INTERBANK COPY BUFFER (64 BYTES)
 ;
 HBX_BUF		.FILL	HBX_BUFSIZ,0
 ;
-; PRIVATE STACK (64 BYTES, 32 ENTRIES)
-;
-		.FILL	HBX_STKSIZ,$FF
-HBX_STACK	.EQU	$
-;
 ; HBIOS PROXY MGMT BLOCK (TOP 32 BYTES)
 ;
 #IFDEF ROMBOOT
@@ -558,6 +537,8 @@ HBX_STACK	.EQU	$
 ;   HBIOS CORE
 ;==================================================================================================
 ;
+HB_STKSIZ	.EQU	$60	; HBIOS PRIVATE STACK SIZE
+HB_ISTKSIZ	.EQU	$40	; HBIOS INTERRUPT STACK SIZE
 ;
 ;==================================================================================================
 ;   ENTRY VECTORS (JUMP TABLE)
@@ -584,6 +565,10 @@ HB_START:
 	XOR	A
 	OUT0	(Z180_RCR),A
 
+	; MASK OFF TIMER INTERRUPTS
+	XOR	A
+	OUT0	(Z180_TCR),A
+
 	; SET DEFAULT CPU CLOCK MULTIPLIERS (XTAL / 2)
 	XOR	A
 	OUT0	(Z180_CCR),A
@@ -656,7 +641,10 @@ HB_START:
 	LD	HL,0
 	LD	DE,0
 	LD	BC,$8000
-	CALL	HB_BNKCPY
+	CALL	HBX_BNKCPY
+;
+	; INTERRUPTS ARE ENABLED BY BNKCPY!!!
+	DI			; RE-DISABLE INTERRUPTS
 ;
 ; TRANSITION TO HBIOS IN RAM BANK
 ;
@@ -670,6 +658,10 @@ HB_RAMFLAG	.DB	FALSE	; ASSUME FALSE, SET TO TRUE BELOW AFTER RAM TRANSITION
 ; EXECUTION RESUMES HERE AFTER SWITCH TO RAM BANK
 ;
 HB_START1:			; BNKCALL ARRIVES HERE, BUT NOW RUNNING IN RAM BANK
+;
+	; INTERRUPTS ARE ENABLED BY BNKCALL!!!
+	DI			; RE-DISABLE INTERRUTPS
+;
 	LD	SP,HBX_LOC	; RESET STACK SINCE WE DO NOT RETURN
 	LD	A,TRUE		; ACCUM := TRUE 
 	LD	(HB_RAMFLAG),A	; SET RAMFLAG
@@ -719,6 +711,63 @@ HB_START1:			; BNKCALL ARRIVES HERE, BUT NOW RUNNING IN RAM BANK
 ;
 	CALL	NEWLINE2
 	PRTX(STR_BANNER)
+;
+; WE CAN HANDLE INTERRUPTS NOW (HOPEFULLY)
+;
+	HB_DI				; START OF CRITICAL SECTION
+
+#IF (INTTYPE != IT_NONE)
+;
+#IF (INTTYPE == IT_SIMH)
+;
+	; SETUP TIMER INT VECTOR VIA INT MODE 1 IN PAGE ZERO
+	LD	A,$C3			; JP OPCODE
+	LD	($38),A			; ... AT INT VECTOR ADDRESS
+	LD	HL,INT_TIMER		; ADDRESS OF TIMER INT HANDLER
+	LD	($39),HL		; ... IS TARGET OF JP
+;
+#ENDIF
+;
+#IF (INTTYPE == IT_Z180)
+;
+	; SETUP Z180 IVT
+	LD	A,HBX_IVT >> 8		; SETUP HI BYTE OF IVT ADDRESS
+	LD	I,A			; ... AND PLACE IT IN I REGISTER
+	XOR	A			; SETUP LO BYTE OF IVT ADDRESS
+	OUT0	(Z180_IL),A		; ... AND PLACE IN Z180 IL REGISTER
+;
+	IM	2			; SWITCH TO INT MODE 2
+;
+	; MASK ALL EXTERNAL INTERRUPTS FOR NOW
+	XOR	A			; INT0-2 DISABLED
+	OUT0	(Z180_ITC),A		; WRITE TO INT/TRAP CONTROL REGISTER
+;
+	; SETUP Z180 TIMER0 INTERRUPT VECTOR IN IVT
+	LD	HL,INT_TIMER
+	LD	(HBX_IVT + Z180_IVTIM0),HL
+
+	; SETUP PERIODIC TIMER INTERRUPT ON TIMER 0
+	LD	HL,(CB_CPUKHZ)		; 50HZ = 18432000 / 20 / 50 / X, SO X = CPU KHZ 
+	LD	B,0
+	LD	C,Z180_RLDR0L		; INITIALIZE TIMER 0 RELOAD REGISTER
+	OUT	(C),L
+	INC	C
+	OUT	(C),H
+	LD	C,Z180_TMDR0L		; INITIALIZE TIMER 0 DATA REGISTER
+	OUT	(C),L
+	INC	C
+	OUT	(C),H
+	LD	A,%00010001		; ENABLE TIMER0 INT AND DOWN COUNTING
+	OUT0	(Z180_TCR),A
+;	
+#ENDIF
+;
+#ENDIF
+
+	HB_EI				; END OF CRITICAL SECTION
+;
+; DISPLAY PLATFORM INFORMATION
+;
 	CALL	NEWLINE2
 	PRTX(STR_PLATFORM)
 	PRTS(" @ $")
@@ -788,13 +837,20 @@ INITSYS3:
 ;
 	CALL	PRTSUM			; PRINT UNIT/DEVICE SUMMARY TABLE
 ;
+;
+;
+;	CALL	TSTPT
+;	LD	HL,($FF00 + 2)
+;	CALL	JPHL
+;	CALL	TSTPT
+;
 ; CHAIN TO OS LOADER
 ;
 #IFDEF ROMBOOT
 	; PERFORM BANK CALL TO OS IMAGES BANK
 	LD	A,BID_OSIMG	; CHAIN TO OS IMAGES BANK
 	LD	HL,0		; ENTER AT ADDRESS 0
-	CALL	HB_BNKCALL	; GO THERE
+	CALL	HBX_BNKCALL	; GO THERE
 	HALT			; WE SHOULD NEVER COME BACK!
 #ELSE
 	; COPY OS IMAGE: BID_USR:<IMG START> --> BID_USR:0
@@ -804,12 +860,12 @@ INITSYS3:
 	LD	HL,HB_END
 	LD	DE,0
 	LD	BC,$8000
-	CALL	HB_BNKCPY
+	CALL	HBX_BNKCPY
 ;
 	; PERFORM BANK CALL TO OS IMAGES BANK
 	LD	A,BID_USR	; CHAIN TO OS IMAGES BANK
 	LD	HL,0		; ENTER AT ADDRESS 0
-	CALL	HB_BNKCALL	; GO THERE
+	CALL	HBX_BNKCALL	; GO THERE
 	HALT			; WE SHOULD NEVER COME BACK!
 
 
@@ -924,11 +980,11 @@ HB_DISPATCH:
 ;
 	; CHECK STACK INTEGRITY
 	PUSH	AF
-	LD	A,(HBX_STACK - HBX_STKSIZ + $08)
+	LD	A,(HB_STACK - HB_STKSIZ + $08)
 	CP	$FF
 	CALL	NZ,PANIC
 	LD	A,$FF
-	LD	(HBX_STACK - HBX_STKSIZ + $08),A
+	LD	(HB_STACK - HB_STKSIZ + $08),A
 	POP	AF
 	RET
 HB_DISPCALL:
@@ -1473,7 +1529,7 @@ SYS_BNKCPY:
 	;POP	AF
 	; *DEBUG* END
 
-	CALL	BNKCPY
+	CALL	HBX_BNKCPY
 	XOR	A
 	RET
 ;
@@ -1719,17 +1775,55 @@ CIO_IDLE:
 ; TIMER INTERRUPT
 ;
 HB_TIMINT:
+	; INCREMENT TICK COUNTER (32 BIT)
+	LD	HL,HB_TICKS		; POINT TO TICK COUNTER
+	INC	(HL)
+	JR	NZ,HB_TIMINT1
+	INC	HL
+	INC	(HL)
+	JR	NZ,HB_TIMINT1
+	INC	HL
+	INC	(HL)
+	JR	NZ,HB_TIMINT1
+	INC	HL
+	INC	(HL)
+;
+HB_TIMINT1:
+;
+#IF 0
+;
+	LD	HL,TEMPCNT
+	DEC	(HL)
+	JR	NZ,HB_TIMINT2
+	LD	(HL),250
+;	
+	LD	A,'*'
+	CALL	COUT
+	JR	HB_TIMINT2
+;
+TEMPCNT	.DB	250
+;
+#ENDIF
+;
+HB_TIMINT2:
+;
+#IF (INTTYPE == IT_Z180)
+	; ACK/RESET INTERRUPT
+	IN0	A,(Z180_TCR)
+	IN0	A,(Z180_TMDR0L)
+#ENDIF
+;	
 	RET
 ;
 ; BAD INTERRUPT HANDLER
 ;
 HB_BADINT:
+	CALL	NEWLINE2
+	PRTS("+++ BAD INT: $")
+	CALL	_REGDMP
+	CALL	CONTINUE
 	RET
 ;
-; WRAPPER FOR CALL TO HB_BNKCPY FOR USE BY INTERNAL HBIOS FUNCTIONS
-;
-BNKCPY	.EQU	HB_BNKCPY
-;
 ; ADD AN ENTRY TO THE UNIT TABLE AT ADDRESS IN HL
 ;   C: DEVICE TYPE ID
 ;   B: UNIT INDEX
@@ -2838,9 +2932,13 @@ 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
+HB_TICKS	.FILL	4,0		; 32 BIT TICK COUNTER
+;
+		.FILL	HB_STKSIZ,$FF	; 48 ENTRY STACK FOR HBIOS FUNCTION PROCESSING
+HB_STACK	.EQU	$		; TOP OF HBIOS STACK
+;
+		.FILL	HB_ISTKSIZ,$FF	; 32 ENTRY STACK FOR INTERRUPT PROCESSING
+HB_ISTACK	.EQU	$		; TOP OF INTERRUPT PROCESSING STACK
 ;
 STR_BANNER	.DB	"RetroBrew HBIOS v", BIOSVER, ", ", TIMESTAMP, "$"
 STR_PLATFORM	.DB	PLATFORM_NAME, "$"

Source/HBIOS/md.asm

@@ -190,7 +190,7 @@ MD_READ:
 	LD	A,B		; GET DESTINATION BANK
 	LD	(HB_DSTBNK),A	; SET IT
 	POP	BC
-	CALL	BNKCPY		; DO THE INTERBANK COPY
+	CALL	HBX_BNKCPY	; DO THE INTERBANK COPY
 	XOR	A
 	RET
 ;
@@ -222,7 +222,7 @@ MD_WRITE:
 	LD	A,B		; GET DESTINATION BANK
 	LD	(HB_DSTBNK),A	; SET IT
 	POP	BC
-	CALL	BNKCPY		; DO THE INTERBANK COPY
+	CALL	HBX_BNKCPY	; DO THE INTERBANK COPY
 	XOR	A
 	RET
 ;

Source/HBIOS/ppk.asm

@@ -76,7 +76,7 @@ PPK_INIT:
 	CALL	PRTHEXBYTE
 ;
 	; PRECOMPUTE TIMEOUT LOOP COUNT (CPU KHZ / 16)
-	LD	HL,(CPUKHZ)		; GET CPU SPEED IN KHZ
+	LD	HL,(CB_CPUKHZ)		; GET CPU SPEED IN KHZ
 	LD	B,4			; SHIFT 4 TIMES TO DIVIDE BY 16
 PPK_INIT1:
 	SRL	H			; RIGHT SHIFT

Source/HBIOS/romldr.asm

@@ -23,7 +23,7 @@ ZSYSIMG	.EQU	$5000
 #IF (PLATFORM == PLT_UNA)
 	JP	$FFFD			; INVOKE UBIOS FUNCTION
 #ELSE
-	JP	$FFF0			; INVOKE HBIOS FUNCTION
+	JP	HB_INVOKE		; INVOKE HBIOS FUNCTION
 #ENDIF
 	.FILL	(010H - $),0FFH		; RST 10
 	RET
@@ -47,8 +47,9 @@ ZSYSIMG	.EQU	$5000
 ;   LOADER
 ;==================================================================================================
 ;
-	DI			; NO INTERRUPTS
-	IM	1		; INTERRUPT MODE 1
+	;DI			; NO INTERRUPTS
+	;IM	1		; INTERRUPT MODE 1
+;
 	LD	SP,BL_STACK	; SETUP STACK
 ;
 ; COPY OURSELVES TO HI RAM FOR PHASE 2
@@ -74,6 +75,19 @@ PHASE2:
 	CALL	DELAY_INIT
 #ENDIF
 
+#IF (PLATFORM != PLT_UNA)
+	; PREP THE USER BANK (SETUP DEFAULT PAGE ZERO)
+	LD	B,BF_SYSSETCPY	; HBIOS FUNC: SETUP BANK COPY
+	LD	D,BID_USR	; D = DEST BANK = USER BANK
+	LD	E,BID_BIOS	; E = SRC BANK = BIOS BANK
+	LD	HL,256		; HL = COPY LEN = 1 PAGE = 256 BYTES
+	RST	08		; DO IT
+	LD	B,BF_SYSBNKCPY	; HBIOS FUNC: PERFORM BANK COPY
+	LD	HL,0		; COPY FROM BIOS ADDRESS 0
+	LD	DE,0		; TO USER ADDRESS 0
+	RST	08		; DO IT
+#ENDIF
+
 	; RUN THE BOOT LOADER MENU
 	JP	DOBOOTMENU
 ;
@@ -190,11 +204,13 @@ DB_INVALID:
 ;
 GOMON:
 	CALL	LDMON
-	JP	MON_SERIAL
+	LD	HL,MON_SERIAL		; JUMP TO MONITOR, SERIAL ENTRY
+	JR	EXECUSR
 ;
 GOMONDSKY:
 	CALL	LDMON
-	JP	MON_DSKY
+	LD	HL,MON_DSKY
+	JR	EXECUSR
 ;
 LDMON:
 	LD	DE,STR_BOOTMON
@@ -219,9 +235,6 @@ GOCPM2:
 	LD	BC,$01FC		; UNA FUNC: SET BOOTSTRAP HISTORY
 	RST	08			; CALL UNA
 #ELSE
-	;LD	B,BF_SYSHCBPUTW		; HB FUNC: PUT HCB WORD
-	;LD	C,HCB_BOOTVOL		; BOOT VOLUME (UNIT, SLICE)
-	;LD	DE,$0100
 	LD	B,BF_SYSSET		; HB FUNC: SET HBIOS PARAMETER
 	LD	C,BF_SYSSET_BOOTINFO	; HB SUBFUNC: SET BOOT INFO
 	LD	A,(HB_CURBNK)		; GET CURRENT BANK ID FROM PROXY DATA
@@ -229,7 +242,8 @@ GOCPM2:
 	LD	DE,$0100		; BOOT VOLUME (UNIT, SLICE)
 	RST	08
 #ENDIF
-	JP	CPM_ENT
+	LD	HL,CPM_ENT		; CPM ENTRY VECTOR
+	JR	EXECUSR
 ;
 GOZSYS:
 	LD	DE,STR_BOOTZSYS
@@ -237,6 +251,15 @@ GOZSYS:
 	LD	HL,ZSYSIMG
 	JR	GOCPM2
 ;
+EXECUSR:
+#IF (PLATFORM == PLT_UNA)
+	JP	(HL)
+#ELSE
+	LD	A,BID_USR		; WITH USER BANK ACTIVE
+	CALL	HB_BNKCALL		; GO THERE
+	CALL	PANIC			; WE ARE NOT SUPPOSED TO RETURN
+#ENDIF
+;
 GOLIST:
 	LD	DE,STR_LIST
 	CALL	WRITESTR
@@ -352,7 +375,8 @@ BOOTDISK:
 	; JUMP TO COLD BOOT ENTRY
 	CALL	NEWLINE			; FORMATTING
 	LD	HL,(BB_CPMENT)		; GET THE ENTRY POINT
-	JP	(HL)			; ... AND GO
+	;JP	(HL)			; ... AND GO
+	JP	EXECUSR			; ... AND GO
 ;
 ; PRINT LIST OF ALL DRIVES UNDER UNA
 ;
@@ -882,6 +906,11 @@ CIN:
 ;
 CST:
 	; SAVE INCOMING REGISTERS (AF IS OUTPUT)
+	CALL	DLY64
+	CALL	DLY64
+	CALL	DLY64
+	CALL	DLY64
+	CALL	DLY64
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
@@ -889,6 +918,8 @@ CST:
 	; GET CONSOLE INPUT STATUS VIA HBIOS
 	LD	C,CIODEV_CONSOLE	; CONSOLE UNIT TO C
 	LD	B,BF_CIOIST		; HBIOS FUNC: INPUT STATUS
+	;XOR	A			; *DEBUG*
+	;INC	A			; *DEBUG*
 	RST	08			; HBIOS RETURNS STATUS IN A
 ;
 	; RESTORE REGISTERS (AF IS OUTPUT)

Source/HBIOS/simrtc.asm

@@ -71,7 +71,7 @@ SIMRTC_GETTIM:
 	LD	HL,SIMRTC_BUF		; SOURCE ADR
 	POP	DE			; DEST ADR
 	LD	BC,SIMRTC_BUFSIZ	; LENGTH
-	CALL	BNKCPY			; COPY THE CLOCK DATA
+	CALL	HBX_BNKCPY		; COPY THE CLOCK DATA
 ;
 	LD	DE,60			; DELAY 60 * 16US = ~1MS
 	CALL	VDELAY			; SLOW DOWN SIMH FOR CLOCK TICKING TEST
@@ -101,7 +101,7 @@ SIMRTC_SETTIM:
 	LD	(HB_DSTBNK),A		; SET IT
 	LD	DE,SIMRTC_BUF		; DEST ADR
 	LD	BC,SIMRTC_BUFSIZ	; LENGTH
-	CALL	BNKCPY			; COPY THE CLOCK DATA
+	CALL	HBX_BNKCPY		; COPY THE CLOCK DATA
 ;
 	LD	HL,SIMRTC_BUF		; POINT TO TEMP BUF
 	LD	A,SIMRTC_CLKWRITE	; WRITE CLOCK COMMAND

Source/HBIOS/std.asm

@@ -121,7 +121,7 @@ SER_PARSPACE	.EQU	7 << 3
 SER_STOP1	.EQU	0 << 2
 SER_STOP2	.EQU	1 << 2
 ;
-; SEREIAL BAUD RATES ENCODED AS V = 75 * 2^X * 3^Y
+; SERIAL BAUD RATES ENCODED AS V = 75 * 2^X * 3^Y
 ; AND STORED AS 5 BITS: YXXXX
 ;
 SER_BAUD300	.EQU	$02 << 8
@@ -154,6 +154,13 @@ SER_115200_8N1	.EQU	SER_BAUD115200 | SER_DATA8 | SER_PARNONE | SER_STOP1
 SER_230400_8N1	.EQU	SER_BAUD230400 | SER_DATA8 | SER_PARNONE | SER_STOP1
 SER_460800_8N1	.EQU	SER_BAUD460800 | SER_DATA8 | SER_PARNONE | SER_STOP1
 ;
+; INTERRUPT TYPE OPTIONS
+;
+IT_NONE		.EQU	0
+IT_SIMH		.EQU	1
+IT_Z180		.EQU	2
+IT_CTC		.EQU	3
+;
 #INCLUDE "build.inc"			; INCLUDE USER CONFIG, ADD VARIANT, TIMESTAMP, & ROMSIZE
 ;
 #IF ((PLATFORM == PLT_N8) | (PLATFORM == PLT_MK4))

Source/HBIOS/ver.inc

@@ -2,4 +2,4 @@
 #DEFINE	RMN	8
 #DEFINE	RUP	0
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"2.8.0-pre.5"
+#DEFINE BIOSVER	"2.8.0-pre.6"

Source/HBIOS/z180.inc

@@ -65,3 +65,13 @@ Z180_CBAR	.EQU	Z180_BASE + $3A	; MMU COMMON/BANK AREA REGISTER
 ;
 Z180_OMCR	.EQU	Z180_BASE + $3E	; OPERATION MODE CONTROL
 Z180_ICR	.EQU	$3F		; I/O CONTROL REGISTER (NOT RELOCATED!!!)
+;
+Z180_IVINT1	.EQU	0
+Z180_IVINT2	.EQU	2
+Z180_IVTIM0	.EQU	4
+Z180_IVTIM1	.EQU	6
+Z180_IVDMA0	.EQU	8
+Z180_IVDMA1	.EQU	10
+Z180_IVCSIO	.EQU	12
+Z180_IVSER0	.EQU	14
+Z180_IVSER1	.EQU	16