The asm file was an older one the correct one is as below:

What I want to do is to display the data on the 5X7 LED matrix one column by one column, then when the fifth column is reached it goes back to the first one and this continues for a while to display one full character then after a delay the display is updated using the new value of the DPTR, to show the next character.

MOV DPTR,#DATA
PUSH DPH
PUSH DPL
SHOW MOV R3,#255
L2 MOV R4,#25
L1 MOV R5,#5
pop DPL
pop DPH
L3 CLR A
MOVC A,@A+DPTR
MOV P1,A
INC DPTR
NOP
NOP
NOP
MOV P1,#255
ACALL CLOCK
DJNZ R5,L3
ACALL RESET
DJNZ R4,L1
DJNZ R3,L2
ACALL DELAY1
AJMP SHOW

I think there is still something wrong,