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- ;********************************************************
- ;* *
- ;* BSTAM INTERFACE CCS 7710A CARD IN APPLE CP/M SYSTEM *
- ;* *
- ;********************************************************
- ;
- ; Jan 10, 1981
- ;
- ; By Bill Bolton
- ; Software Tools
- ; P.O. Box 80
- ; Newport Beach
- ; NSW, 2106
- ; Australia
- ;
- ; TCY396
- ;
- ;
- ;VERSION 6850/4.5
- ;
- BEGIN ORG 103H
- INITIL JMP INITIU ;UART/USART INITIALATION ENTRY POINT
- INSPORT JMP INSPRU ;STATUS PORT READ ENTRY POINT
- ERRSET JMP ERRSTU ;UART/USART ERROR RESET ENTRY POINT
- INPORT JMP INPRTU ;READ DATA PORT ENTRY POINT
- OUTPORT JMP OUTPRU ;WRITE DATA PORT ENTRY POINT
- ;
- ;
- ;
- TPS EQU 0E0A0H ;STATUS PORT
- TP EQU TPS+1 ;DATA PORT
- ;
- ;
- INITIU:
- CALL SIGNON
- RESET:
- MVI A,17H ;RESET ACIA
- STA TPS
- MVI A,11H ;8 BITS, 2 STOP, 16X CLK, NO PAR
- STA TPS
- RET ;RETURN TO BSTAM
- ;
- ;
- ;
- ;
- INSPRU:
- PUSH B
- LDA TPS ;GET STATUS
- MOV C,A ;C <--- STATUS
- MVI B,1 ;PRESET 8251 TX READY
- ANI 1 ;6850 RX DATA?
- JZ CHKTXE ;NO
- MVI A,02H ;YES, SET 8251 RX DATA
- ORA B ;COMBINE WITH B
- MOV B,A
- CHKTXE: MOV A,C ;A <--- STATUS
- ANI 02H ;TX EMPTY?
- JZ CHKOVR ;NO
- MVI A,04H ;YES, SET 8251 TXE
- ORA B ;COMBINE WITH B
- MOV B,A
- CHKOVR: MOV A,C ;A <--- STATUS
- ANI 20H ;RX OVERRUN
- JZ ENDCHK ;NO
- MVI A,10H ;YES, SET 8251 OE
- ORA B ;COMBINE WITH B
- MOV B,A
- ENDCHK: MOV A,B ;A <--- 8251 LIKE STATUS
- POP B
- RET
- ;
- ERRSTU:
- CALL RESET ;RESET ACIA
- RET ;RETURN TO BSTAM
- ;
- ;
- INPRTU:
- LDA TP ;GET DATA FROM PORT
- RET ;RETURN TO BSTAM
- ;
- ;
- OUTPRU:
- STA TP ;SEND DATA TO REMOTE CPU
- RET ;RETURN TO BSTAM
- ;
- ;
- MESSGE: DB 0DH,0AH,0DH,0AH
- DB 'Version 4.5 - Software Tools',0DH,0AH
- DB 'For APPLE CP/M 2.2 with',0DH,0AH
- DB 'CCS 7710A (6850), no parity',0DH,0AH,'$'
- ;
- SIGNON: PUSH B
- PUSH D
- PUSH H
- LXI D,MESSGE
- MVI C,9
- CALL 5 ;ANOUNCE VERSION TO USER
- POP H
- POP D
- POP B
- RET
- ;
- END BEGIN
-