Subversion Repositories rf6809

; ============================================================================
;        __
;   \\__/ o\    (C) 2013-2022  Robert Finch, Waterloo
;    \  __ /    All rights reserved.
;     \/_//     robfinch<remove>@opencores.org
;       ||
;  
;
; BSD 3-Clause License
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions are met:
;
; 1. Redistributions of source code must retain the above copyright notice, this
;    list of conditions and the following disclaimer.
;
; 2. Redistributions in binary form must reproduce the above copyright notice,
;    this list of conditions and the following disclaimer in the documentation
;    and/or other materials provided with the distribution.
;
; 3. Neither the name of the copyright holder nor the names of its
;    contributors may be used to endorse or promote products derived from
;    this software without specific prior written permission.
;
; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
; DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
; FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
; SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
; CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
; OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;                                                                          
; ============================================================================
;
CR      EQU     $0D             ;ASCII equates
LF      EQU     $0A
TAB     EQU     $09
CTRLC   EQU     $03
CTRLH   EQU     $08
CTRLI   EQU     $09
CTRLJ   EQU     $0A
CTRLK   EQU     $0B
CTRLM   EQU $0D
CTRLS   EQU     $13
CTRLT EQU $14
CTRLX   EQU     $18
XON             EQU     $11
XOFF    EQU     $13

FIRST_CORE      EQU     1
MAX_TASKNO      EQU 63
DRAM_BASE       EQU $10000000

ScreenLocation          EQU             $10
ColorCodeLocation       EQU             $14
ScreenLocation2         EQU             $18
BlkcpySrc                       EQU             $1C
BlkcpyDst                       EQU             $20
Strptr                          EQU             $24
PICptr                          EQU             $28
; Forth Area
; 0x30-0x60

RunningID                       EQU             $800000

; Task control blocks, room for 256 tasks
TCB_NxtRdy              EQU             $00     ; next task on ready / timeout list
TCB_PrvRdy              EQU             $04     ; previous task on ready / timeout list
TCB_NxtTCB              EQU             $08
TCB_Timeout             EQU             $0C
TCB_Priority    EQU             $10
TCB_MSGPTR_D1   EQU             $14
TCB_MSGPTR_D2   EQU             $18
TCB_hJCB                        EQU             $1C
TCB_Status              EQU             $1E
TCB_CursorRow   EQU             $20
TCB_CursorCol   EQU             $21
TCB_hWaitMbx    EQU             $22     ; handle of mailbox task is waiting at
TCB_mbq_next    EQU             $24     ; mailbox queue next
TCB_mbq_prev    EQU             $28     ; mailbox queue previous
TCB_iof_next    EQU             $2C
TCB_iof_prev    EQU             $30
TCB_SPSave              EQU             $34     ; TCB_SPSave area
TCB_mmu_map             EQU             $38

KeybdHead               EQU             $FFFFFC800
KeybdTail               EQU             $FFFFFC900
KeybdEcho               EQU             $FFFFFCA00
KeybdBad                EQU             $FFFFFCB00
KeybdAck                EQU             $FFFFFCC00
KeybdLocks              EQU             $FFFFFCD00
KeybdBuffer             EQU             $FFFFFC000      ; buffer is 16 chars

COREID  EQU             $FFFFFFFE0
MSCOUNT EQU             $FFFFFFFE4
LEDS            EQU             $FFFE60001
VIA                     EQU             $FFFE60000
VIA_PA          EQU             1
VIA_DDRA        EQU             3
VIA_ACR                 EQU             11
VIA_IFR                 EQU             13
VIA_IER                 EQU             14
VIA_T3LL                EQU             18
VIA_T3LH                EQU             19
VIA_T3CMPL      EQU             20
VIA_T3CMPH      EQU             21
TEXTSCR         EQU             $FFFE00000
TEXTREG         EQU             $FFFE0DF00
TEXT_COLS       EQU             0
TEXT_ROWS       EQU             1
TEXT_CURPOS     EQU             34
ACIA            EQU             $FFFE30100
ACIA_TX         EQU             0
ACIA_RX         EQU             0
ACIA_STAT       EQU             1
ACIA_CMD        EQU             2
ACIA_CTRL       EQU             3
ACIA_CTRL2      EQU             11
RTC                             EQU             $FFFE30500      ; I2C
RTCBuf          EQU             $7FC0

KEYBD           EQU             $FFFE30400
KEYBDCLR        EQU             $FFFE30402
PIC                     EQU             $FFFE3F000
SPRITE_CTRL             EQU             $FFFE10000
SPRITE_EN                       EQU             $3C0

OUTSEMA EQU     $EF0000
SEMAABS EQU     $1000
OSSEMA  EQU     $EF0010

BIOS_SCREENS    EQU     $17000000       ; $17000000 to $171FFFFF

; EhBASIC vars:
;
NmiBase         EQU             $FF0013
IrqBase         EQU             $FF0014

IOFocusNdx      EQU             $100

; These variables in global OS storage area

IOFocusList     EQU             $FF0000 ; to $FF000F
IOFocusID               EQU             $FF0010
IrqSource               EQU             $FF0011
IRQFlag                 EQU             $FF0012

; These variables use direct page access
CursorRow       EQU             $110
CursorCol       EQU             $111
CharColor       EQU             $112
ScreenColor     EQU             $113
CursorFlash     EQU             $114
KeyState1       EQU     $120
KeyState2       EQU     $121
KeyLED          EQU     $122
KeybdID         EQU     $124
KeybdBlock      EQU     $126
kbdHeadRcv      EQU     $127
kbdTailRcv      EQU     $128
kbdFifo                 EQU     $40                             ; in local RAM
kbdFifoAlias    EQU     $C00040 ; to $C0007F    ; alias for $40 to $7F
SerhZero                EQU     $130
SerHeadRcv      EQU     $131
SertZero                EQU     $132
SerTailRcv      EQU     $133
SerHeadXmit     EQU     $136
SerTailXmit     EQU     $138
SerRcvXon               EQU     $139
SerRcvXoff      EQU     $140
SerRcvBuf               EQU     $BFF000 ; 4kB serial recieve buffer

farflag EQU             $15F
asmbuf  EQU             $160    ; to $17F

QNdx0           EQU             $780
QNdx1           EQU             QNdx0+2
QNdx2           EQU             QNdx1+2
QNdx3           EQU             QNdx2+2
QNdx4           EQU             QNdx3+2
FreeTCB         EQU             QNdx4+2
TimeoutList     EQU             FreeTCB+2
FreeMbx         EQU             RunningTCB + 2
nMailbox        EQU             FreeMbx + 2
FreeMsg         EQU             nMailbox + 2
nMsgBlk         EQU             FreeMsg + 2


CharOutVec      EQU             $800
CharInVec       EQU             $804
CmdPromptJI     EQU     $808
MonErrVec       EQU             $80C

; Register save area for monitor
mon_DSAVE       EQU             $900
mon_XSAVE       EQU             $902
mon_YSAVE       EQU             $904
mon_USAVE       EQU             $906
mon_SSAVE       EQU             $908
mon_PCSAVE      EQU             $90A
mon_DPRSAVE     EQU             $90E
mon_CCRSAVE     EQU             $90F

mon_numwka      EQU             $910
mon_r1          EQU             $920
mon_r2          EQU             $924

; The ORG directive must set an address a multiple of 4 in order for the Verilog
; output to work correctly.

        org             $FFD0AC
        nop
        nop
        nop
XBLANK
        ldb             #' '
        lbsr    OUTCH
        rts

        org             $FFD0D0
        nop
        nop
CRLF
CRLF1:
        ldb             #CR
        lbsr    OUTCH
        ldb             #LF
        lbsr    OUTCH
        rts

        org             $FFD0F0
        nop
        bra             CRLF1

        org             $FFD1DC
ONEKEY
        jmp             [CharInVec]

        org             $FFD2C0
        nop
LETTER
        lbsr    OUTCH
        rts

        org             $FFD2CC
        nop
        nop
HEX2
        lbsr    DispByteAsHex
        rts
HEX4
        lbsr    DispWordAsHex
        rts

        org             $FFD300
ClearScreenJmp
        lbra    ClearScreen
        org             $FFD308
HomeCursorJmp
        lbra    HomeCursor

        org             $FFD400

; Local RAM test routine
; Checkerboard testing.
; There is 70kB of local RAM
; Does not use any RAM including no stack

ramtest:
        ldy             #0
        lda             #1
        sta             LEDS
        ldd             #$AAA555
ramtest1:
        std             ,y++
        cmpy    #$8000
        blo             ramtest1
        ; now readback values and compare
        ldy             #0
ramtest3:
        ldd             ,y++
        cmpd    #$AAA555
        bne             ramerr
        cmpy    #$8000
        blo             ramtest3
        lda             #2
        sta             LEDS
        jmp             ,u
ramerr:
        lda             #$80
        sta             LEDS
        ldx             #TEXTSCR
        ldb             COREID
        abx
        lda             #'F'
        sta             ,x
        sync
        jmp             ,u

        org             $FFE000
        FDB Monitor
        FDB DumRts      ;       NEXTCMD
        FDB INCH
        FDB INCHE
        FDB INCHEK
        FDB OUTCH
        FDB PDATA
        FDB PCRLF
        FDB PSTRNG
        FDB DumRts                      ; LRA
        FDB DumRts
        FDB DumRts
        FDB DumRts
        FDB DumRts                      ; VINIZ
        FDB DisplayChar ;       VOUTCH
        FDB DumRts                      ; ACINIZ
        FDB DumRts                      ; AOUTCH

DumRts:
        rts

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------

start:
        lda             #$FFF                   ; all cores can do this
        sta             VIA+VIA_DDRA
        lda             #$55                    ; see if we can at least set LEDs
        sta             LEDS
        lda             #1                              ; prime OS semaphore
        sta             OSSEMA+$1000
        ldu             #st6                    ; U = return address
        jmp             ramtest         ; JMP dont JSR
st6:
        lds             #$6FFF          ; boot up stack area
        lda             COREID
        cmpa    #FIRST_CORE
;       beq             st8
;       sync                                            ; halt cores other than 2
st8:
;       bne             skip_init
;       bsr             romToRam
;       ldd             #st7 & $FFFF
;       tfr             d,x
;       jmp             ,x                              ; jump to the BIOS now in local RAM
st7:
        bsr             Delay3s         ; give some time for devices to reset
        lda             #$AA
        sta             LEDS
        lda             #FIRST_CORE
        sta             IOFocusID       ; core #2 has focus
        sta             RunningID
        ; Clear IO focus list
        ldx             #0
st9:
        clr             IOFocusList,x
        inx
        cmpx    #16
        blo             st9
        lda             #24
        sta             IOFocusList+FIRST_CORE

        lda             #$0CE
        sta             ScreenColor
        sta             CharColor
        bsr             ClearScreen
        ldd             #DisplayChar
        std             CharOutVec
        ldd             #SerialPeekCharDirect
        std             CharInVec
        ldb             #24                             ; request IO focus
        lbsr    OSCall
        ldb             COREID
        cmpb    #FIRST_CORE
        beq             init
        bra             skip_init
        bra             multi_sieve
st3:
        lda             #$FF
        sta             LEDS
        bra             st3

        ; initialize interrupt controller
        ; first, zero out all the vectors
init:
        lbsr    rtc_read        ; get clock values
        ldx             #kbdHeadRcv
        ldb             #32                             ; number of bytes to zero out
init1:
        clr             ,x+
        decb
        bne             init1
        lbsr    TimerInit
        lbsr    InitSerial
        ldx             #128
        lda             #1                      ; set irq(bit0), clear firq (bit1), disable int (bit 6), clear edge sense(bit 7)
        ldb             #FIRST_CORE                     ; serving core id
st1:
        clr             PIC,x                   ; cause code
        sta             PIC+1,x
        stb             PIC+2,x
        leax    4,x
        cmpx    #256
        blo             st1
;       lda             #4                              ; make the timer interrupt edge sensitive
;       sta             PIC+4                   ; reg #4 is the edge sensitivity setting
;       sta             PIC                             ; reg #0 is interrupt enable
        lda             #$81                    ; make irq edge sensitive
        sta             PIC+$FD
        lda             #31                             ; enable timer interrupt
;       sta             PIC+9
        ldb             #1
        stb             OUTSEMA+SEMAABS ; set semaphore to 1 available slot
skip_init:
        andcc   #$EF                    ; unmask irq
        lda             #56
        sta             TEXTREG+TEXT_COLS
        lda             #29
        sta             TEXTREG+TEXT_ROWS
        bsr             ClearScreen
        bsr             HomeCursor
        lda             #5
        sta             LEDS
        ldd             #msgStartup
        bsr             DisplayString
        ldx             #0
        ldd             #0
        lbsr    ShowSprites
        lbsr    KeybdInit
        ldd             KeybdID
        bsr             DispWordAsHex
        jmp             MonitorStart

msgStartup
        fcb             "rf6809 12-bit System Starting.",CR,LF,0

;------------------------------------------------------------------------------
; The checkpoint register must be cleared within 1 second or a NMI interrupt
; will occur. checkpoint should be called with a JSR so that the global ROM
; routine is called.
;
; Modifies:
;               none
;------------------------------------------------------------------------------

checkpoint:
        clr             $FFFFFFFE1      ; writing any value will do
        rts

;------------------------------------------------------------------------------
; Copy the system ROM to local RAM
; Running the code from local RAM is probably an order of magnitude faster
; then running from the global ROM. It also reduces the network traffic to
; run from local RAM.
;
; Modifies:
;               d,x,y
;------------------------------------------------------------------------------

romToRam:
        ldx             #$FFC000
        ldy             #$00C000
romToRam1:
        ldd             ,x++
        std             ,y++
        cmpx    #0
        bne             romToRam1
        rts

;------------------------------------------------------------------------------
; Multi-core sieve program.
;------------------------------------------------------------------------------

; First fill screen chars with 'P' indicating prime positions
; Each core is responsible for the Nth position where N is the
; core number minus two.
;
multi_sieve:
        lda             #'P'                                    ; indicate prime
        ldb             COREID                          ; find out which core we are
        subb    #FIRST_CORE
        ldx             #0                                              ; start at first char of screen
        abx
multi_sieve3:
        sta             TEXTSCR,x                       ; store 'P'
        leax    8,x                                             ; advance to next position
        cmpx    #4095
        blo             multi_sieve3
        jsr             checkpoint
        addb    #2                                              ; start sieve at 2 (core id)
        lda             #'N'                                    ; flag position value of 'N' for non-prime
multi_sieve2:
        ldx             #0
        abx                                                                     ; skip the first position - might be prime
multi_sieve1:
        abx                                                                     ; increment
        sta             TEXTSCR,x
        cmpx    #4095
        blo             multi_sieve1
        jsr             checkpoint
        addb    #8                                              ; number of cores working on it
        cmpb    #4080
        blo             multi_sieve2
multi_sieve4:                                   ; hang machine
        sync
        lbra    Monitor

;------------------------------------------------------------------------------
; Single core sieve.
;------------------------------------------------------------------------------

sieve:
        lda             #'P'                                    ; indicate prime
        ldx             #0                                              ; start at first char of screen
sieve3:
        sta             TEXTSCR,x                       ; store 'P'
        inx                                                                     ; advance to next position
        cmpx    #4095
        blo             sieve3
        ldb             #2                                              ; start sieve at 2
        lda             #'N'                                    ; flag position value of 'N' for non-prime
sieve2:
        ldx             #0
        abx                                                                     ; skip the first position - might be prime
sieve1:
        abx                                                                     ; increment
        sta             TEXTSCR,x
        cmpx    #4095
        blo             multi_sieve1
        incb                                                            ; number of cores working on it
        cmpb    #4080
        blo             sieve2
sieve4:                                                         ; hang machine
        rts

;------------------------------------------------------------------------------
; Three second delay for user convenience and to allow some devices time to
; reset.
;------------------------------------------------------------------------------

Delay3s:
        ldd             #9000000
dly3s1:
        cmpb    #$FF
        bne             dly3s2
dly3s2:
        sta             LEDS
        subd    #1
        bne             dly3s1
        rts

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------
ShiftLeft5:
        aslb
        rola
        aslb
        rola
        aslb
        rola
        aslb
        rola
        aslb
        rola
        rts

;------------------------------------------------------------------------------
; Parameters:
;               b = core id of core to copy
;------------------------------------------------------------------------------
;
CopyVirtualScreenToScreen:
        pshs    d,x,y,u
        ; Compute virtual screen location for core passed in accb.
        tfr             b,a
        asla
        asla
        asla
        asla
        ora             #$C00
        clrb
        tfr             d,x
        pshs    d
        ldy             #TEXTSCR
        ldu             #56*29/2
cv2s1:
        ldd             ,x++
        std             ,y++
        leau    -1,u
        cmpu    #0
        bne             cv2s1
        ; reset the cursor position in the text controller
        puls    x
        ldb             CursorRow,x
        lda             #56
        mul
        tfr             d,y
        ldb             CursorCol,x
        tfr             y,x
        abx
        stx             TEXTREG+TEXT_CURPOS
        puls    d,x,y,u,pc

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------
;
CopyScreenToVirtualScreen:
        pshs    d,x,y,u
        bsr             GetScreenLocation
        tfr             d,y
        ldx             #TEXTSCR
        ldu             #56*29/2
cs2v1:
        ldd             ,x++
        std             ,y++
        leau    -1,u
        cmpu    #0
        bne             cs2v1
        puls    d,x,y,u,pc

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------
        fcb             "TEXTSCR "
        fcw             TextOpen
        fcw             TextClose
        fcw             TextRead
        fcw             TextWrite
        fcw             TextSeek

TextOpen:
        rts
TextClose:
        rts
TextRead:
        rts
TextWrite:
        rts
TextSeek:
        rts

;------------------------------------------------------------------------------
; Clear the screen and the screen color memory
; We clear the screen to give a visual indication that the system
; is working at all.
;
; Modifies:
;               none
;------------------------------------------------------------------------------

ClearScreen:
        pshs    d,x,y,u
        ldx             #56*29
        tfr             x,u
        bsr             GetScreenLocation
        tfr             d,y
        ldb             #' '                            ; space char
cs1:
        stb             ,y+                                     ; set text to space
        leax    -1,x                            ; decrement x
        bne             cs1
        ldb             COREID                  ; update colors only if we have focus
        cmpb    IOFocusID
        bra             cs3
        ldy             #TEXTSCR+$2000
;       lda             CharColor
        lda             #$0CE
        tfr             u,x                                     ; get back count
cs2:
        sta             ,y+
        dex                                                             ; decrement x
        bne             cs2
cs3:
        puls    d,x,y,u,pc

;------------------------------------------------------------------------------
; Scroll text on the screen upwards
;
; Modifies:
;               none
;------------------------------------------------------------------------------

ScrollUp:
        pshs    d,x,y,u
        ldy             #(56*29-1)/2    ; y = num chars/2 to move
        bsr             GetScreenLocation
        tfr             d,x
        tfr             d,u
        leax    56,x                    ; x = index to source row
scrup1:
        ldd             ,x++                    ; move 2 characters
        std             ,u++
        dey
        bne             scrup1
        lda             #29
        bsr             BlankLine
        puls    d,x,y,u,pc

;------------------------------------------------------------------------------
; Blank out a line on the display
;
; Modifies:
;               none
; Parameters:
;       acca = line number to blank
;------------------------------------------------------------------------------

BlankLine:
        pshs    d,x
        pshs    a
        bsr             GetScreenLocation
        tfr             d,x
        puls    a
        ldb             #56             ; b = # chars to blank out from video controller
        mul                                     ; d = screen index (row# * #cols)
        leax    d,x
        lda             #' '
        ldb             #56             ; b = # chars to blank out from video controller
blnkln1:
        sta             ,x+
        decb
        bne             blnkln1
        puls    d,x,pc

;------------------------------------------------------------------------------
; Get the location of the screen memory. The location
; depends on whether or not the task has the output focus.
;
; Modifies:
;               d
; Retuns:
;               d = screen location
;------------------------------------------------------------------------------

GetScreenLocation:
        lda             COREID                  ; which core are we?
        cmpa    IOFocusID               ; do we have the IO focus
        bne             gsl1                            ; no, go pick virtual screen address
        ldd             #TEXTSCR                ; yes, we update the real screen
        rts
gsl1:
        ldd             #$7800
        rts

;------------------------------------------------------------------------------
; HomeCursor
; Set the cursor location to the top left of the screen.
;
; Modifies:
;               none
;------------------------------------------------------------------------------

HomeCursor:
        pshs    d,x
        clr             CursorRow
        clr             CursorCol
        ldb             COREID
        cmpb    IOFocusID
        bne             hc1
        clra
        sta             TEXTREG+TEXT_CURPOS
hc1:
        puls    d,x,pc

;------------------------------------------------------------------------------
; Update the cursor position in the text controller based on the
;  CursorRow,CursorCol.
;
; Modifies:
;               none
;------------------------------------------------------------------------------
;
UpdateCursorPos:
        pshs    d,x
        ldb             COREID                          ; update cursor position in text controller
        cmpb    IOFocusID                       ; only for the task with the output focus
        bne             ucp1                                    
        lda             CursorRow
        anda    #$3F                                    ; limit of 63 rows
        ldb             TEXTREG+TEXT_COLS
        mul
        tfr             d,x
        ldb             CursorCol
        abx
        stx             TEXTREG+TEXT_CURPOS
ucp1:
        puls    d,x,pc

;------------------------------------------------------------------------------
; Calculate screen memory location from CursorRow,CursorCol.
; Also refreshes the cursor location.
;
; Modifies:
;               d
; Returns:
;       d = screen location
;------------------------------------------------------------------------------
;
CalcScreenLoc:
        pshs    x
        lda             CursorRow
        ldb             #56
        mul
        tfr             d,x
        ldb             CursorCol
        abx
        ldb             COREID                          ; update cursor position in text controller
        cmpb    IOFocusID                       ; only for the task with the output focus
        bne             csl1                                    
        stx             TEXTREG+TEXT_CURPOS
csl1:
        bsr             GetScreenLocation
        leax    d,x
        tfr             x,d
        puls    x,pc

;------------------------------------------------------------------------------
; Display a character on the screen.
; If the task doesn't have the I/O focus then the character is written to
; the virtual screen.
;
; Modifies:
;               none
; Parameters:
;       accb = char to display
;------------------------------------------------------------------------------
;
DisplayChar:
        lbsr    SerialPutChar
        pshs    d,x
        cmpb    #CR                                     ; carriage return ?
        bne             dccr
        clr             CursorCol               ; just set cursor column to zero on a CR
        bsr             UpdateCursorPos
dcx14:
        lbra            dcx4
dccr:
        cmpb    #$91                            ; cursor right ?
        bne             dcx6
        lda             CursorCol
        cmpa    #56
        bhs             dcx7
        inca
        sta             CursorCol
dcx7:
        bsr             UpdateCursorPos
        puls    d,x,pc
dcx6:
        cmpb    #$90                            ; cursor up ?
        bne             dcx8            
        lda             CursorRow
        beq             dcx7
        deca
        sta             CursorRow
        bra             dcx7
dcx8:
        cmpb    #$93                            ; cursor left ?
        bne             dcx9
        lda             CursorCol
        beq             dcx7
        deca
        sta             CursorCol
        bra             dcx7
dcx9:
        cmpb    #$92                            ; cursor down ?
        bne             dcx10
        lda             CursorRow
        cmpa    #29
        beq             dcx7
        inca
        sta             CursorRow
        bra             dcx7
dcx10:
        cmpb    #$94                            ; cursor home ?
        bne             dcx11
        lda             CursorCol
        beq             dcx12
        clr             CursorCol
        bra             dcx7
dcx12:
        clr             CursorRow
        bra             dcx7
dcx11:
        cmpb    #$99                            ; delete ?
        bne             dcx13
        bsr             CalcScreenLoc
        tfr             d,x
        lda             CursorCol               ; acc = cursor column
        bra             dcx5
dcx13
        cmpb    #CTRLH                  ; backspace ?
        bne             dcx3
        lda             CursorCol
        beq             dcx4
        deca
        sta             CursorCol
        bsr             CalcScreenLoc
        tfr             d,x
        lda             CursorCol
dcx5:
        ldb             1,x
        stb             ,x++
        inca
        cmpa    #56
        blo             dcx5
        ldb             #' '
        dex
        stb             ,x
        bra             dcx4
dcx3:
        cmpb    #LF                             ; linefeed ?
        beq             dclf
        pshs    b
        bsr     CalcScreenLoc
        tfr             d,x
        puls    b
        stb             ,x
        ; ToDo character color
;       lda             CharColor
;       sta             $2000,x
        bsr             IncCursorPos
        bra             dcx4
dclf:
        bsr             IncCursorRow
dcx4:
        puls    d,x,pc

;------------------------------------------------------------------------------
; Increment the cursor position, scroll the screen if needed.
;
; Modifies:
;               none
;------------------------------------------------------------------------------

IncCursorPos:
        pshs    d,x
        lda             CursorCol
        inca
        sta             CursorCol
        cmpa    #56
        blo             icc1
        clr             CursorCol               ; column = 0
        bra             icr1
IncCursorRow:
        pshs    d,x
icr1:
        lda             CursorRow
        inca
        sta             CursorRow
        cmpa    #29
        blo             icc1
        deca                                                    ; backup the cursor row, we are scrolling up
        sta             CursorRow
        bsr             ScrollUp
icc1:
        bsr             UpdateCursorPos
icc2:
        puls    d,x,pc  

;------------------------------------------------------------------------------
; Display a string on the screen.
;
; Modifies:
;               none
; Parameters:
;               d = pointer to string
;------------------------------------------------------------------------------
;
DisplayString:
        pshs    d,x
        tfr             d,x
dspj2:                                          ; lock semaphore for access
        lda             OUTSEMA+1
        beq             dspj2
dspj1B:
        ldb             ,x+                             ; move string char into acc
        beq             dsretB          ; is it end of string ?
        lbsr    OUTCH                   ; display character
        bra             dspj1B
dsretB:
        clr             OUTSEMA+1       ; unlock semaphore
        puls    d,x,pc

DisplayStringCRLF:
        pshs    d
        bsr             DisplayString
        ldb             #CR
        lbsr    OUTCH
        ldb             #LF
        lbsr    OUTCH
        puls    d,pc
        
;
; PRINT CR, LF, STRING
;
PSTRNG
        BSR             PCRLF
        BRA             PDATA
PCRLF
        PSHS    X
        LDX             #CRLFST
        BSR             PDATA
        PULS    X
        RTS

PRINT
        JSR             OUTCH
PDATA
        LDB             ,X+
        CMPB    #$04
        BNE             PRINT
        RTS

CRLFST
        fcb     CR,LF,4

DispDWordAsHex:
        bsr             DispWordAsHex
        exg             d,x
        bsr             DispWordAsHex
        exg             d,x
        rts

DispWordAsHex:
        exg             a,b
        bsr             DispByteAsHex
        exg             a,b
        bsr             DispByteAsHex
        rts

DispByteAsHex:
  pshs  b
        lsrb
        lsrb
        lsrb
        lsrb
        lsrb
        lsrb
        lsrb
        lsrb
        bsr             DispNyb
        puls    b
        pshs    b
        lsrb
        lsrb
        lsrb
        lsrb
        bsr             DispNyb
        puls    b

DispNyb
        pshs    b
        andb    #$0F
        cmpb    #10
        blo             DispNyb1
        addb    #'A'-10
        lbsr    OUTCH
        puls    b,pc
DispNyb1
        addb    #'0'
        lbsr    OUTCH
        puls    b,pc

;==============================================================================
; Timer
;==============================================================================

OPT INCLUDE "d:\cores2022\rf6809\software\boot\timer.asm"
OPT INCLUDE "d:\cores2022\rf6809\software\boot\i2c.asm"
OPT INCLUDE "d:\cores2022\rf6809\software\boot\rtc_driver.asm"

;==============================================================================
; Keyboard I/O
;==============================================================================

OPT INCLUDE "d:\cores2022\rf6809\software\boot\scancodes.asm"
OPT INCLUDE "d:\cores2022\rf6809\software\boot\keyboard.asm"

        fcb             "KEYBOARD"
        fcw             KeybdOpen
        fcw             KeybdClose
        fcw             KeybdRead
        fcw             KeybdWrite
        fcw             KeybdSeek

; Keyboard Open:
; Initialize the keyboard buffer head and tail indexes
;
KeybdOpen:
        rts

; Keyboard Close:
; Nothing to do except maybe clear the keyboard buffer
;
KeybdClose:
        rts
;
KeybdRead:
        rts
;
KeybdWrite:
        rts

KeybdSeek:
        rts

;==============================================================================
; Serial I/O
;==============================================================================

OPT INCLUDE "d:\cores2022\rf6809\software\boot\serial.asm"

;------------------------------------------------------------------------------
; Check if there is a keyboard character available. If so return true (<0)
; otherwise return false (0) in accb.
;------------------------------------------------------------------------------
;
KeybdCheckForKeyDirect:
        bra             DBGCheckForKey

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------
INCH:
        pshs    b
INCH2:
        ldb             COREID
        cmpb    IOFocusID       ; if we do not have focus, block
        bne             INCH2                   
;       ldb             #$800                   ; block if no key available, get scancode directly
;       bra             GetKey
;       jsr             [CharInVec]     ; vector is being overwritten somehow
        lbsr    SerialPeekCharDirect
        tsta
        bmi             INCH1                   ; block if no key available
        leas    1,s                             ; get rid of blocking status
        rts
INCH1:
        puls    b                                       ; check blocking status
        tstb
        bmi     INCH                    ; if blocking, loop
        ldd             #-1                             ; return -1 if no char available
        rts

INCHE:
        bsr             INCH
        bra             INCHEK3

INCHEK:
        bsr             INCH
        tst             KeybdEcho
        beq             INCHEK1
INCHEK3:
        cmpa    #CR
        bne             INCHEK2
        lbsr            CRLF
        bra             INCHEK1
INCHEK2:
        lbsr    DisplayChar
INCHEK1:
        rts

OUTCH:
        jmp             [CharOutVec]

;------------------------------------------------------------------------------
; r1 0=echo off, non-zero = echo on
;------------------------------------------------------------------------------
;
SetKeyboardEcho:
        stb             KeybdEcho
        rts


;------------------------------------------------------------------------------
; Parameters:
;               x,d     bitmap of sprites to enable
;------------------------------------------------------------------------------

ShowSprites:
        stx             SPRITE_CTRL+SPRITE_EN
        std             SPRITE_CTRL+SPRITE_EN+2
        rts

;==============================================================================
; Femtiki Operating System.
;==============================================================================

OSCallTbl:
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             0
        fcw             ReleaseIOFocus
        fcw             0
        fcw             RequestIOFocus

OSCall:
        ; wait for availability
osc1:
        tst             OSSEMA+1
        beq             osc1
        aslb
        ldx             #OSCallTbl
        abx
        tst             ,x
        beq             oscx
        jmp             [,x]
oscx:
        clr             OSSEMA+1
        rts

RequestIOFocus:
        ldb             COREID
        ldx             #IOFocusList
        abx
        sta             ,x
        tst             IOFocusID
        lbne    oscx
        stb             IOFocusID
        lbra    oscx

ReleaseIOFocus:
        ldb             COREID
        ldx             #IOFocusList
        abx
        clr             ,x                                              ; clear the request indicator
        lbsr    CopyScreenToVirtualScreen
        cmpb    IOFocusID                       ; are we the one with the focus?
        lbne    oscx
        ; We had the focus, so now a new core needs the focus.
        ; Search the focus list for a requestor. If no requester
        ; is found, give focus to core #1.
        lda             #15
riof2:
        incb
        andb    #15
        abx
        tst             ,x
        bne             riof1
        deca
        bne             riof2
        ; If no focus is requested by anyone, give to core #1
        ldb             #1
        lda             #24
        sta             ,x
riof1:
        stb             IOFocusID
        lbsr    CopyVirtualScreenToScreen
        lbra    oscx
                
        
;==============================================================================
; Disassembler
;==============================================================================

OPT     include "d:\cores2022\rf6809\software\boot\disassem.asm"
        
;==============================================================================
; System Monitor
;==============================================================================

CmdPrompt:
        lbsr    CRLF
        ldb             #'$'
        lbsr    OUTCH
        lbra    OUTCH

msgF09Starting:
        fcb             "Femtiki F09 Multi-core OS Starting",CR,LF,0

MonitorStart:
        ldd             #msgF09Starting
        lbsr    DisplayString
        ldd             #HelpMsg
        lbsr    DisplayString
        ldd             #CmdPrompt
        std             CmdPromptJI
        ldd             #DisplayErr
        std             MonErrVec
        ldd             #$63FF                  ; default app stack
        std             mon_SSAVE
Monitor:
        leas    $6FFF                           ; reset stack pointer
        clrb                                                    ; turn off keyboard echo
        lbsr    SetKeyboardEcho
        ; Reset IO vectors
        ldd             #SerialPeekCharDirect
        std             CharInVec
        ldd             #DisplayChar
        std             CharOutVec
        ldd             #CmdPrompt
        std             CmdPromptJI
;       jsr             RequestIOFocus
PromptLn:
        jsr             [CmdPromptJI]

; Get characters until a CR is keyed
        
Prompt3:
        ldd             #-1                                     ; block until key present
        lbsr    INCH
        cmpb    #CR
        beq             Prompt1
        lbsr    OUTCH
        bra             Prompt3

; Process the screen line that the CR was keyed on
;
Prompt1:
        ldd             #$5050
        std             LEDS
;       ldb             RunningID
;       cmpb    #61
;       bhi             Prompt3
        ldd             #$5151
        std             LEDS
        clr             CursorCol                       ; go back to the start of the line
        lbsr    CalcScreenLoc   ; calc screen memory location
        tfr             d,y
        ldd             #$5252
        std             LEDS
skipDollar:
        bsr             MonGetNonSpace
        cmpb    #'$'
        beq             skipDollar              ; skip over '$' prompt character
        lda             #$5353
        std             LEDS

; Dispatch based on command character
;
Prompt2:
        cmpb    #'<'
        bne             PromptHelp
        bsr             MonGetch
        cmpb    #'>'
        bne             Monitor
        bsr             MonGetch
        cmpb    #'s'
        bne             Prompt2a
        ldd             #SerialPeekCharDirect
        std             CharInVec
        ldd             #SerialPutChar
        std             CharOutVec
        bra             Monitor
Prompt2a:
        cmpb    #'c'
        bne             Monitor
        ldd             #GetKey
        std             CharInVec
        ldd             #DisplayChar
        std             CharOutVec
        bra             Monitor
PromptHelp:
        cmpb    #'?'                    ; $? - display help
        bne             PromptC
        ldd             #HelpMsg
        lbsr    DisplayString
        bra             Monitor
PromptC:
        cmpb    #'C'
        bne             PromptD
        lbsr    ClearScreen
        lbsr    HomeCursor
        bra             Monitor
PromptD:
        cmpb    #'D'
        bne             PromptColon
        bsr             MonGetch
        cmpb    #'R'
        bne             DumpMemory
        bra             DumpRegs
PromptColon:
        cmpb    #':'
        bne             PromptF
        lbra    EditMemory
PromptF:
        cmpb    #'F'
        bne             PromptJ
        bsr             MonGetch
        cmpb    #'I'
        bne             PromptFL
        bsr             MonGetch
        cmpb    #'G'
        bne             Monitor
        jmp             $FE0000
PromptFL:
        cmpb    #'L'
        bne             Monitor
        lbra    DumpIOFocusList
PromptJ:
        cmpb    #'J'
        lbeq    jump_to_code
PromptR:
        cmpb    #'R'
        bne             Prompt_s
        ldu             #Monitor
        lbra    ramtest
Prompt_s:
        cmpb    #'s'
        bne             PromptT
        lbsr    SerialOutputTest
        bra             Monitor
PromptT:
        cmpb    #'T'
        bne             PromptU
        bsr             MonGetch
        cmpb    #'I'
        bne             Monitor
        bsr             MonGetch
        cmpb    #'R'
        bne             Monitor
        lbsr    rtc_read
        bra             Monitor
PromptU:
        cmpb    #'U'
        bne             Monitor
        lbra    disassem

MonGetch:
        ldb             ,y
        iny
        rts

MonGetNonSpace:
        bsr             MonGetCh
        cmpb    #' '
        beq             MonGetNonSpace
        rts

;------------------------------------------------------------------------------
; Ignore blanks in the input
; Y = text pointer
; D destroyed
;------------------------------------------------------------------------------
;
ignBlanks:
ignBlanks1:
        bsr             MonGetch
        cmpb    #' '
        beq             ignBlanks1
        dey
        rts

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------
GetTwoParams:
        bsr             ignBlanks
        bsr             GetHexNumber    ; get start address of dump
        ldd             mon_numwka
        std             mon_r1
        ldd             mon_numwka+2
        std             mon_r1+2
        bsr             ignBlanks
        bsr             GetHexNumber    ; get end address of dump
        ldd             mon_numwka
        std             mon_r2
        ldd             mon_numwka+2
        std             mon_r2+2
        rts

;------------------------------------------------------------------------------
; Get a range, the end must be greater or equal to the start.
;------------------------------------------------------------------------------
GetRange:
        bsr             GetTwoParams
        ldd             mon_r2+2
        subd    mon_r1+2
        ldd             mon_r2
        sbcb    mon_r1+1
        sbca    mon_r1
        lbcc    grng1
        jsr             [MonErrVec]
        lbra    Monitor
grng1:
        rts

shl_numwka:
        asl             mon_numwka+3
        rol             mon_numwka+2
        rol             mon_numwka+1
        rol             mon_numwka
        rts

;------------------------------------------------------------------------------
; Get a hexidecimal number. Maximum of twelve digits.
;
; Modifies:
;       Y = text pointer (updated)
;       D = number of digits
;       mon_numwka contains number
;------------------------------------------------------------------------------
;
GetHexNumber:
        clrd
        std             mon_numwka      ; zero out work area
        std             mon_numwka+2
        pshs    x
        ldx             #0                                      ; max 12 eight digits
gthxn2:
        bsr             MonGetch
        bsr             AsciiToHexNybble
        cmpb    #-1
        beq             gthxn1
        bsr             shl_numwka
        bsr             shl_numwka
        bsr             shl_numwka
        bsr             shl_numwka
        andb    #$0f
        orb             mon_numwka+3
        stb             mon_numwka+3
        inx
        cmpx    #12
        blo             gthxn2
gthxn1:
        tfr             x,d
        puls    x,pc

;GetDecNumber:
;       phx
;       push    r4
;       push    r5
;       ldx             #0
;       ld              r4,#10
;       ld              r5,#10
;gtdcn2:
;       jsr             MonGetch
;       jsr             AsciiToDecNybble
;       cmp             #-1
;       beq             gtdcn1
;       mul             r2,r2,r5
;       add             r2,r1
;       dec             r4
;       bne             gtdcn2
;gtdcn1:
;       txa
;       pop             r5
;       pop             r4
;       plx
;       rts

;------------------------------------------------------------------------------
; Convert ASCII character in the range '0' to '9', 'a' to 'f' or 'A' to 'F'
; to a hex nybble.
;------------------------------------------------------------------------------
;
AsciiToHexNybble:
        cmpb    #'0'
        blo             gthx3
        cmpb    #'9'
        bhi             gthx5
        subb    #'0'
        rts
gthx5:
        cmpb    #'A'
        blo             gthx3
        cmpb    #'F'
        bhi             gthx6
        subb    #'A'
        addb    #10
        rts
gthx6:
        cmpb    #'a'
        blo             gthx3
        cmpb    #'z'
        bhi             gthx3
        subb    #'a'
        addb    #10
        rts
gthx3:
        ldb             #-1             ; not a hex number
        rts

AsciiToDecNybble:
        cmpb    #'0'
        bcc             gtdc3
        cmpb    #'9'+1
        bcs             gtdc3
        subb    #'0'
        rts
gtdc3:
        ldb             #-1
        rts

DisplayErr:
        ldd             #msgErr
        lbsr    DisplayString
        jmp             Monitor

DisplayStringDX
        std             Strptr
        stx             Strptr+2
        jsr             DisplayString
        rts

msgErr:
        fcb     "**Err",CR,LF,0

HelpMsg:
        fcb             "? = Display help",CR,LF
        fcb     "CLS = clear screen",CR,LF
;       db      "S = Boot from SD Card",CR,LF
        fcb     ": = Edit memory bytes",CR,LF
;       db      "L = Load sector",CR,LF
;       db      "W = Write sector",CR,LF
        fcb "DR = Dump registers",CR,LF
        fcb     "D = Dump memory",CR,LF
;       db      "F = Fill memory",CR,LF
        fcb "FL = Dump I/O Focus List",CR,LF
        fcb "FIG = start FIG Forth",CR,LF
;       db      "KILL n = kill task #n",CR,LF
;       db      "B = start tiny basic",CR,LF
;       db      "b = start EhBasic 6502",CR,LF
        fcb     "J = Jump to code",CR,LF
        fcb "RAM = test RAM",CR,LF
;       db      "R[n] = Set register value",CR,LF
;       db      "r = random lines - test bitmap",CR,LF
;       db      "e = ethernet test",CR,LF
        fcb     "s = serial output test",CR,LF
;       db      "T = Dump task list",CR,LF
;       db      "TO = Dump timeout list",CR,LF
        fcb     "TI = display date/time",CR,LF
;       db      "TEMP = display temperature",CR,LF
        fcb     "U = unassemble",CR,LF
;       db      "P = Piano",CR,LF,0
        fcb             0

msgRegHeadings
        fcb     CR,LF,"  D/AB     X      Y      U      S       PC    DP  CCR",CR,LF,0

nHEX4:
        jsr             HEX4
        rts

nXBLANK:
        ldb             #' '
        lbra    OUTCH

;------------------------------------------------------------------------------
; Dump Memory
;
; Usage:
;       $D FFFC12 FFFC20
;
; Dump formatted to look like:
;               :FFFC12 012 012 012 012 555 666 777 888
;
;------------------------------------------------------------------------------

DumpMemory:
        bsr             GetRange
        ldy             #0
        ldy             mon_r1+2
dmpm2:
        lbsr    CRLF
        ldb             #':'
        lbsr    OUTCH
        tfr             y,d
        ;addd   mon_r1+2                                        ; output the address
        lbsr    DispWordAsHex
        ldb             #' '
        lbsr    OUTCH
        ldx             #8                                                              ; number of bytes to display
dmpm1:
;       ldb             far [mon_r1+1],y
        ;ldb            [mon_r1+2],y
        ldb             ,y
        iny
        lbsr    DispByteAsHex                   ; display byte
        ldb             #' '                                                    ; followed by a space
        lbsr    OUTCH
        clrb
        clra
        lbsr    INCH
        cmpb    #CTRLC
        beq             dmpm3
        dex
        bne             dmpm1
        ; Now output ascii
        ldb             #' '
        lbsr    OUTCH
        ldx             #8                                                              ; 8 chars to output
        leay    -8,y                                                    ; backup pointer
dmpm5:
;       ldb             far [mon_r1+1],y        ; get the char
;       ldb             [mon_r1+2],y                    ; get the char
        ldb             ,y
        cmpb    #$20                                                    ; is it a control char?
        bhs             dmpm4
        ldb             #'.'
dmpm4:
        lbsr    OUTCH
        iny
        dex
        bne             dmpm5
        cmpy    mon_r2+2
        blo             dmpm2
dmpm3:
        lbsr    CRLF
        lbra    Monitor

;------------------------------------------------------------------------------
; Edit Memory
;
; Usage:
;       $$:FFFC12 8 "Hello World!" 0
;
; Dump formatted to look like:
;               :FFFC12 012 012 012 012 555 666 777 888
;
;------------------------------------------------------------------------------

EditMemory:
        ldu             #8                                              ; set max byte count
        lbsr    GetHexNumber    ; get the start address
        ldx             mon_numwka+2
EditMem2:
        lbsr    ignBlanks                       ; skip over blanks
        lbsr    GetHexNumber    ; get the byte value
        tstb                                                            ; check for valid value
        bmi             EditMem1                        ; if invalid, quit
        ldb             mon_numwka+3    ; get value
        stb             ,x+                                             ; update memory at address
        leau    -1,u                                    ; decremeent byte count
        cmpu    #0
        bne             EditMem2                        ; go back for annother byte
EditMem1:
        lbsr    MonGetch                        ; see if a string is being entered
        cmpb    #'"'
        bne             EditMem3                        ; no string, we're done
        ldu             #40                                             ; string must be less than 40 chars
EditMem4:
        lbsr    MonGetch                        ; look for close quote
        cmpb    #'"'
        bne             EditMem6                        ; end of string?
        ldu             #8                                              ; reset the byte count
        bra             EditMem2
EditMem6:                       
        stb             ,x+                                             ; store the character in memory
        leau    -1,u                                    ; decrement byte count
        cmpu    #0
        bhi             EditMem4                        ; max 40 chars
EditMem3:
        lbra    Monitor
        

;------------------------------------------------------------------------------
; Dump Registers
;
;       Usage:
;               $DR
;------------------------------------------------------------------------------

DumpRegs:
        ldd             #msgRegHeadings
        lbsr    DisplayString
        bsr             nXBLANK
        ldd             mon_DSAVE
        bsr             nHEX4
        bsr             nXBLANK
        ldd             mon_XSAVE
        bsr             nHEX4
        bsr             nXBLANK
        ldd             mon_YSAVE
        bsr             nHEX4
        bsr             nXBLANK
        ldd             mon_USAVE
        bsr             nHEX4
        bsr             nXBLANK
        ldd             mon_SSAVE
        bsr             nHEX4
        bsr             nXBLANK
        ldb             mon_PCSAVE+1
        lbsr    DispByteAsHex   
        ldd             mon_PCSAVE+2
        bsr             nHEX4
        bsr             nXBLANK
        ldd             mon_DPRSAVE
        jsr             HEX2
        bsr             nXBLANK
        lda             mon_CCRSAVE
        lbsr    HEX2
        bsr             nXBLANK
        lbra    Monitor

;------------------------------------------------------------------------------
; Jump to code
;
; Registers are loaded with values from the monitor register save area before
; the code is jumped to.
;
; J <address>
;------------------------------------------------------------------------------

jump_to_code:
        bsr             GetHexNumber
        sei
        lds             mon_SSAVE
        ldd             #<jtc_exit              ; setup stack for RTS back to monitor
        pshs    d
        ldb             #>jtc_exit
        pshs    b
        ldd             mon_numwka+2    ; get the address parameter
        pshs    d
        ldb             mon_numwka+1
        pshs    b
        ldd             mon_USAVE
        pshs    d
        ldd             mon_YSAVE
        pshs    d
        ldd             mon_XSAVE
        pshs    d
        lda             mon_DPRSave
        pshs    a
        ldd             mon_DSAVE
        pshs    d
        lda             mon_CCRSAVE
        pshs    a
        puls    far ccr,d,dpr,x,y,u,pc
jtc_exit:
        sts             >mon_SSAVE              ; need to use extended addressing, no direct page setting
        leas    $6FFF                                   ; reset stack to system area, dont modify flags register!
        pshs    ccr                                             ; now the stack can be used
        pshs    a                                                       ; save acca register so we can use it
        tfr             dpr,a                                   ; a = outgoing dpr value
        sta             >mon_DPRSAVE    ; force extended addressing mode usage here dpr is not set
        clra                                                            ; dpg register must be set to zero before values are 
        tfr             a,dpr                                   ; saved in the monitor register save area.
        puls    a                                                       ; get back acca
        std             mon_DSAVE                       ; save regsters, can use direct addressing now
        stx             mon_XSAVE
        sty             mon_YSAVE
        stu             mon_USAVE
        puls    a                                                       ; get back ccr
        sta             mon_CCRSAVE             ; and save it too
        ; Reset vectors in case they got toasted.
        ldd             #SerialPeekCharDirect
        std             CharInVec
        ldd             #DisplayChar
        std             CharOutVec
        ldd             DisplayErr
        std             MonErrVec
        ; todo set according to coreid
        lbra    DumpRegs                        ; now go do a register dump

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------

DumpIOFocusList:
        ldx             #0
dfl2:
        ldb             IOFocusList,x
        cmpb    #24
        bne             dfl1
        tfr             x,d
        lbsr    DispByteAsHex
        ldb             #' '
        lbsr    OUTCH
dfl1:
        inx
        cmpx    #16
        blo             dfl2
        lbsr    CRLF
        lbra    Monitor
        

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------
swi3_rout:
        sei
        puls    a
        sta             mon_CCRSAVE
        puls    D,DPR,X,Y,U
        std             mon_DSAVE
        stx             mon_XSAVE
        sty             mon_YSAVE
        stu             mon_USAVE
        tfr             dpr,a
        sta             mon_DPRSAVE
        puls    a
        sta             mon_PCSAVE
        puls    D
        std             mon_PCSAVE+1
        sts             mon_SSAVE
        lds             #$3FFF
        cli
        jmp             DumpRegs
swi3_exit:
        sei
        lds             mon_SSAVE
        ldd             mon_PCSAVE+1
        pshs    d
        lda             mon_PCSAVE
        pshs    a
        ldu             mon_USAVE
        ldy             mon_YSAVE
        ldx             mon_XSAVE
        pshs    x,y,u
        lda             mon_DPRSAVE
        pshs    a
        ldd             mon_DSAVE
        pshs    d
        lda             mon_CCRSAVE
        pshs    a
        tfr             a,ccr
        cli
        rti

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------
firq_rout:
        rti

irq_rout:
;       lbsr    SerialIRQ       ; check for recieved character
;       lbsr    TimerIRQ

        ; Reset the edge sense circuit in the PIC
        lda             #31                                                     ; Timer is IRQ #31
        sta             IrqSource               ; stuff a byte indicating the IRQ source for PEEK()
        sta             PIC+16                                  ; register 16 is edge sense reset reg   
        lda             VIA+VIA_IFR
        bpl             notTimerIRQ2
        bita    #$800
        beq             notTimerIRQ2
        clr             VIA+VIA_T3LL
        clr             VIA+VIA_T3LH
        inc             $E00037                                 ; update timer IRQ screen flag
notTimerIRQ2:

        lda             IrqBase                 ; get the IRQ flag byte
        lsra
        ora             IrqBase
        anda    #$E0
        sta             IrqBase

;       inc             TEXTSCR+54              ; update IRQ live indicator on screen
        
        ; flash the cursor
        ; only bother to flash the cursor for the task with the IO focus.
;       lda             COREID
;       cmpa    IOFocusID
;       bne             tr1a
;       lda             CursorFlash             ; test if we want a flashing cursor
;       beq             tr1a
;       lbsr    CalcScreenLoc   ; compute cursor location in memory
;       tfr             d,y
;       lda             $2000,y                 ; get color code $2000 higher in memory
;       ldb             IRQFlag                 ; get counter
;       lsrb
;       lsra
;       lsra
;       lsra
;       lsra
;       lsrb
;       rola
;       lsrb
;       rola
;       lsrb
;       rola
;       lsrb
;       rola
;       sta             $E00000,y               ; store the color code back to memory
tr1a:
        rti

;------------------------------------------------------------------------------
;------------------------------------------------------------------------------
nmi_rout:
        ldb             COREID
        lda             #'I'
        ldx             #TEXTSCR+40
        sta             b,x
rti_insn:
        rti

; Special Register Area
        org             $FFFFE0

; Interrupt vector table

        org             $FFFFF0
        fcw             rti_insn                ; reserved
        fcw             swi3_rout               ; SWI3
        fcw             rti_insn                ; SWI2
        fcw             firq_rout               ; FIRQ
        fcw             irq_rout                ; IRQ
        fcw             start                           ; SWI
        fcw             nmi_rout                ; NMI
        fcw             start                           ; RST