'==========================================================
'
' PicStic4 PicBASIC Pro Demo for saving strings [ending w/CR] into
' the EEPROM of PicStic4 and retrieving them at random
'
'==========================================================
'
Include "MODEDEFS.BAS"
B0  var byte     'SERIAL INPUT CHARACTER VARIABLE
B1  var byte     'EEPROM DATA VARIABLE [ODD OR EVEN]
B2  var byte     'ODD [MSB] EVEN [LSB] ADDRESS POINTER OF THE EEPROM DATA
B3  var byte     'SEARCH VARIABLE
B4  var W2.byte0 '[LSB W2] IS THE ADDRESS LOCATION POINTER INTO THE EEPROM [BYTE POINTER]
B5  var W2.byte1 '[MSB W2] IS THE ADDRESS LOCATION POINTER INTO THE EEPROM [BYTE POINTER]
B6  var W3.byte0 '[LSB W3] IS THE ADDRESS LOCATION POINTER [WORD POINTER]
B7  var W3.byte1 '[MSB W3] IS THE ADDRESS LOCATION POINTER [WORD POINTER]
B8  var byte     'TEMPORARY VARIABLE STORAGE FOR B4
B9  var byte     'TEMPORARY VARIABLE STORAGE FOR B5
B19 var byte     'COMMAND [FOR PASS]
B20 var byte     'LSB OF THE PARAMETER [FOR PASS]
B21 var byte     'MSB OF THE PARAMETER [FOR PASS]
W2  var word
W3  var word
 
SYMBOL  EE86 = 1983             '2048 - 64 - 1 = 1983 BYTES
START:  W3=0

START1: SEROUT 7,N9600,["1-Write EEPROM",13,10]
        SEROUT 7,N9600,["2-Read EEPROM",13,10]
        SERIN 6,N9600,B0
        if B0=49 then EWR
        if B0<>50 then START1

ERD:    SEROUT 7,N9600,["Print String #? [0-255]"]
        SERIN 6,N9600,#B0
        FOR B3=0 TO B0          

ERD1:   if W3>EE86 then ERD4    
        GOSUB RADRS
        if B3<>B0 then ERD2
        SEROUT 7,N9600,[B1]             'print if this is it

ERD2:   W3=W3+1
        if B1=10 then ERD3
        GOTO ERD1

ERD3:   NEXT B3
        GOTO START

ERD4:   SEROUT 7,N9600,[13,10,"END of EEPROM",13,10] : GOTO START

EWR:    SEROUT 7,N9600,["Enter characters",13,10]
        SEROUT 7,N9600,["CR ends string",13,10]
        SEROUT 7,N9600,["CR CR quits",13,10]
        B2=0

EWR1:   if W3>EE86 then ERD4
        SERIN 6,N9600,B0        
        if B0=13 and B2=0 then EWR3
        if B0=13 and B2<>0 then ERD4
        B2=0         

EWR2:   SEROUT 7,N9600,[#W3,32,B0,13,10]
        GOSUB WADRS
        W3=W3+1
        if W3>EE86 then ERD4
        if B0=13 then EWR4
        GOTO EWR1

EWR3:   B2=1 : GOTO EWR2 

EWR4:   B0=10 : goto EWR2

SADRS:  w2=w3/2
        B19=30 : B20=B4 : B21=B5 : REM  SET EEPROM ADDRESS
        call    PASS
        if B19=30 and B20=255 and B21=255 then SADRS1
        gosub ERR : goto SADRS

SADRS1: RETURN

RADRS:  GOSUB SADRS
        B19=32 : B20=0 : B21=0 : REM  READ EEPROM ADDRESS
        call    PASS
        if B19=32 then RADRS1
        gosub ERR : goto RADRS

RADRS1: W2=W3//2
        if W2=1 then RADRS3
        
RADRS2: B1=B20 : RETURN

RADRS3: B1=B21 : RETURN


WADRS:  GOSUB RADRS
        B8=B20 : B9=B21
        GOSUB SADRS
        W2=W3//2
        if W2=1 then WADRS2

WADRS1: B20=B0 : B21=B9 : GOTO WADRS3

WADRS2: B21=B0 : B20=B8

WADRS3: B19=31 : REM  WRITE EEPROM ADDRESS
        call    PASS
        if B19=31 and B20=255 and B21=255 then WADRS4
        gosub ERR : goto WADRS3

WADRS4: RETURN

ERR:    SEROUT 7,N9600,["Comm Error-",#B19,13,10] : RETURN