80-Bus News

  

November–December 1984, Volume 3, Issue 6











Page 36 of 55











OO6F 006c 0037 0034 0034 0034 8000 8000 8000 8000 8002 8002 8002 8002 8004 8005 8007 8008 8009 800C 800D 800F 8011 8013 8014 8017 8018 801A 801D 8021 8022 8023 8025 8027 8028 802A 802B 802C 80 2F 8030 8032 8033

j NAA RRAR RRA KA AK KARE RAK RARER RAR ARR EIKRRK RRR 3% cuTs8000 * 3% A program to provide output from the * ys Sinclair Spectrum in NAS-SYS tape * 5% format at 1200 Baud. * 3% M D Hendry * 3% edited 10th Oct 1984 * [FRI IOI TOR IOI ICR FOR FR III ROR ROR TR IR IO TORR IIR HK Re

s;Delay loop values for tone generation

;practical values/calculated values DELI EQU 111 3110.64 DEL2 EQU 108 3108.03 DEL3 EQU 55 354.55 DEL4 EQU 52 351.94

ORG 8000H LOAD E¶

ARGI DS 2 ;POKE start address here ARG2 DS 2 ;POKE end address + 1 here

;Execute here

DI ;stemporarily stop keyboard interrupt

LD BOO PLO PUSH BC SCP ;set flag for high bit CALL SndBitc POP BC DINZ PLO ;send 256 high bits LD BO j;set up counter LD LO j;set up output register PLI PUSH BC CALL BytOut POP BC DJINZ PLL LD HL (ARGI) j;adapted from NAS-SYS PLIA LD DE (ARG2) EX DE AL SCF SBC HL DE JR C Finish EX DE HL LD BO PL2 PUSH BC SCF CALL SndBit POP BC DINZ PL2 XOR A LD BOS

soutput 256 nulls

CD7380 = PL3 3EFF

10F9

AF

BA

2002

43

04

58 PL4 7D

CD7380

7C

CD7380

7B

CD7380

TA

CD7380

7c

7E PL5

TE

cD7380

23

10F6

060B

79

CD7380 PL6 AF

LOFA

18AC

FB Finish

co

ES B0Call

cs 6F cd7c80 cl El i)

AF BytOut

cD9080

0608

c5 BOL CB3D

CALL BOCall LD A OFFH DJINZ PL3 XOR A

CP D

JR NZ PL4 LD BE

INC B

LD E B

LDA L CALL BOCall LD A H CALL 80Call LDA E CALL BOCall LD A D CALL BOCal1

CALL BOCall INC HL

DINZ PL5

LD B OBH LDA C CALL BOCalL XOR A

DINZ PL6

JR PLIA

EI srestore keyboard interrupt RET sand return to BASIC

PUSH HL ;preserve registers PUSH BC

LDLA

CALL Byt Out

POP BC ;recover registers POP HL

RET

;Output a byte from the L register

XOR A sset up for a start bit CALL SndBit

LD B 8

PUSH, BC

SRL L ssend 8 bits of data

36

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This is an OCR’d version of the scanned page and likely contains recognition errors.











Page 36 of 55