, - .
. . , 1. - :
1. 
.
2.
3.
4. 2 3
5. , . .
. FF20 , , 21 , .
:
INBYT: MVI A,1;
STA 0FF20h;
WAIT: LDA 0FF20h;
ORA A;
JP WAIT;
LDA 0FF21h;
MVI 1, STA , . , , ORA A , JP (, S=0) . (S=1) . 15 .
: ( ), - :
INBYT: MVI A,1;
OUT 20h;
WAIT: IN 20h;
ORA A;
JP WAIT;
IN 21h;
3 .
, , , , . READY, DPORT. :
WRITE: PUSH PSW;
WAIT: IN READY;
ORA A;
JP WAIT;
POP PSW;
OUT DPORT;
. 8- READY 8 . . MASK, , , .
|
|
|
IN READY;
ANI MASK;
, .
- , . , .
, , . , , .
- . . , , .
. , ( ) , .
, . 25 /, 160 /, 1500 /, 10000 / . , .
, .
. , , .
() . , , .
580 . INT . , INTE H-. , . INT=1 ( INTE=1), RST, , .
|
|
|
, .. . , INT . .
: , .
, .
.
, . RS- . Q INT . PRINT RST7.
INT=1 INTE=1.
INTA# RST7 ( 111). RST7 0038h , . *. CHAR . . HL . , . . .
org 0038h;
; 0038h
PUSH PSW;
PUSH H;
LHLD CHAR; (H, L)
MOV A,M;
CPI '*';
JZ ENDT; ?
OUT PRINT; ,
INX H;
SHLD CHAR;
POP H;
POP PSW;
ENDT: EI;
RET;
***;
21 , 122 . 1.5 90 ( RST). EI, .. . RETURN.
