Sharp MZ-700 Series Owner's Manual page 96

2.8.5 Preparing machine language programs
A m a c h i n e language p r o g r a m w h i c h fills t h e e n t i r e display screen w i t h t h e c h a r a c t e r s s u p p o r t e d b y t h e
M Z - 7 0 0 is p r e s e n t e d in t h i s s e c t i o n as an e x a m p l e .
T h e f o l l o w i n g B A S I C p r o g r a m l o a d s s u c h a m a c h i n e p r o g r a m i n t o m e m o r y a n d calls it.
10 L I M I T $ B F F F
2 0 GOSUB 5 0
3 0 USRC$C0003
4 0 END
5 0 FOR I = 4 9 1 5 2 TO 4 9 1 8 !
6 0 READ M
7 0 POKE I , M
8 0 NEXT I
9 0 RETURN
Limits the BASIC area to $BFFF.
•Calls the machine language program.
DATA 1 9 7 : R E M PUSH BC
1 10 DATA 2 1 3 : REM PUSH DE
1 2 0 DATA 2 2 9 :REI1 PUSH HL
1 3 0 DATA 2 2 , 0 : R E M LO D , 0
1 4 0 DATA 3 3 , 0 , 2 0 8 :REf1 LD H L , D 0 0 0 H
1 5 0 DATA 1 , 2 3 2 , 3 • REM LD B C ,
1
0 0 0
1 6 0 DATA 2 4 3 : R E M DJ
1 7 0 DATA 21 1 , 2 2 7 : R E M OUT C E 3 H T A
1 8 0 DATA 1 1 4 ^ REM S T 0 : L D
C H L 3 , D
:
1 9 0 DATA 3 5 :REM INC HL !
2 0 0 DATA 2 0 :REM INC D
2 1 0
DATA 11 : R E n DEC BC
2 2 0 DATA 120 : REM LD A , B
2 3 0 DATA 177 :REM
OR C
2 4 0 DATA 1 9 4 , 1 4 , 1 9 2 • REM JP N 2 , S T O
2 5 0 DATA 2 1 1 , 2 2 5 : REM
OUT C E 1 H ] , A
2 6 0 DATA 2 5 1 : R E M
E I
2 7 0
DATA 2 2 5 :REt1 POP HL
2 8 0 DATA 2 0 9 • R E M POP DE
2 9 0 DATA
193 :REM POP BC
3 0 0 DATA 2 0 1 : R E M
RET
Reads data for the machine language program from DATA
statements and writes it into the machine language area.
Beginning of data for the machine language program.
Switches the memory block to video RAM. (See page
155).
Sets a display code to video RAM.
Switches the memory block to RAM. (See page 127.)
Returns to the BASIC program.
If t h e m a c h i n e language p r o g r a m h a s b e e n g e n e r a t e d w i t h t h e m o n i t o r a n d saved o n c a s s e t t e t a p e u n d e r
t h e file n a m e D I S P L A Y C O D E , use t h e f o l l o w i n g p r o g r a m t o call t h e m a c h i n e language p r o g r a m .
1 1 0 L I M I T S B F F F
1 1 0 L O A D " D I S P L A Y C O D E "
1 2 0 U S R C S C 0 0 0 )
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