Hello All,

I have been able to get a machine code print routine to work.
The code that will print two lines to the LCD screen follows.

Fred Martin had requested I send the code to the HandyBoard list.

Note that No interrupts have been set up.  

The Print screen routine is copied to Zero page with each 
new character printed, (to account for interrupts etc trashing zero 
page as well).

I had a few problems getting the display to work, and had to 
obtain a manual for the display.
Some problems I discovered:

1.  You need to Turn Display On first, (with an $0C code).

2.  The display in One line is so dark, the words can not be seen.
     The display thus needs to be operated in two line display.

3.  The screen buffer is bigger than the display.  Hence you need to
     write multiple characters to the end of line one, to get to line 
     two.


__________________________________________


* HC11 - Equates
*
PORTA        EQU        $00                        ; Port A data register
PORTB        EQU        $04                        ; Port B data register
PORTC        EQU        $03                        ; Port C latched data register
PORTD   EQU        $08                        ; Port D data register
PORTE        EQU        $0A                        ; Port E data register
DDRC        EQU        $07                        ; Data Direction register for port C
HPRIO        EQU        $3C                        ; Highest Priority Interrupt and misc.
*
* Display Equates
*
LCDtmpA
        EQU        $0009
LCDrout
        EQU        $0010
*
        ORG        $BFFE
        FDB        $8000         ;org to the reset vector
*
*  Start of Prog
*
        ORG        $8000        
        LDS        #$E000
*
*  Do Print to screen
*
        JSR        CPYprt
        LDAA        #$00                        
        LDAB        #$0C                        ; Display On /  Cursor Off / Flash Off
        JSR        LCDrout
*
        JSR        CPYprt
        LDAA        #$00                        
        LDAB        #$38                        ; Two Display
        JSR        LCDrout
*
        JSR        CPYprt
        LDAA        #$00                        
        LDAB        #$03                        ; Home and Clear Display
        JSR        LCDrout
*
        LDX        #Line1                        ; Tell to Print Line 1
        STX        SCRend
PL1        JSR        CPYprt
        LDAA        #$02                        
        LDX        SCRend
        LDAB        $00,X
        INX
        STX        SCRend
        JSR        LCDrout
        LDX        SCRend
        CPX        #Line2
        BNE        PL1
*
        LDAA        #24                        ; Move to Next Line
NewL        STAA        SCRend
        JSR        CPYprt
        LDAA        #$02                        
        LDAB        #40
        JSR        LCDrout
        LDAA        SCRend
        DECA
        BNE        NewL
*
        LDX        #Line2                        ; Tell to Print Line 2
        STX        SCRend
PL2        JSR        CPYprt
        LDAA        #$02                        
        LDX        SCRend
        LDAB        $00,X
        INX
        STX        SCRend
        JSR        LCDrout
        LDX        SCRend
        CPX        #Lend
        BNE        Pl2
*
AGAIN        LDAA        #$FA
        STAA        $7000
*
        LDX        #$8000                ; Delay for count
LOP1        DEX
        BNE        LOP1
*
        LDAA        #$F5
        STAA        $7000
*
        LDX        #$8000                ; Delay for count
LOP2        DEX
        BNE        LOP2
*
        JMP        AGAIN
*
Line1        FCC        'Print Line 1 !!!'
Line2        FCC        'This is Line 2 !'
Lend        FCB        $00
*
*
*  Copy print routine to Zero Page
*
CPYprt        LDX        #SCRbeg
        LDY        #LCDrout
LCDloop
        LDAA        0,X
        STAA        0,Y
        INX
        INY
        CPX        #SCRend
        BNE        LCDloop
        RTS
*
*   Print Routine:  A - Command, B - Data
*     Copied to Zero Page memory and Run there
*
SCRbeg        SEI                                ; disable interrupts
        LDX        #$1000
        BCLR        HPRIO,X %00100000        ; put into single chip mode
        BCLR        PORTA,X %00010000        ; turn off LCD E line
        STAA        LCDtmpA                        ; Temp A store
        CLR        DDRC,X                        ; make port C input
LCDBsy        LDAA        #1
        STAA        PORTB,X                        ; read operation from LCD (AKF-added ',X')
        BSET        PORTA,X %00010000        ; frob LCD on
        LDAA        PORTC,X                        ; get status
        BCLR        PORTA,X %00010000        ; frob LCD off
        ANDA        #$80                        ; bit 7 is busy flag
        BNE        LCDBsy
        LDAA        #$FF
        STAA        DDRC,X                        ; make port C output
        LDAA        LCDtmpA                        ; Temp A store
        STAA        PORTB,X                        ; high byte is control
        STAB        PORTC,X                        ; low byte is data
        BSET        PORTA,X %00010000
        BCLR        PORTA,X %00010000        ; frob LCD
        BSET        HPRIO,X %00100000        ; put into expanded chip mode
        CLI                                ; enable interrupts
        RTS                                ; return to monitor command loop
SCRend        RMB        2

 Charles Hacker
 School of Engineering
 Griffith University - Gold Coast
 PMB 50 Gold Coast Mail Centre
 Southport Queensland 9726
 Australia.
 Email - C.Hacker@eas.gu.edu.au
 Ph. (07) 55948 670
 Fax.(07) 55948 065