Commodore Plus 4 - Page 397

The Modem and Other RS232 Devices 38S
40 DATA931,940,948
50 DATA864,879,893,905
60 PRINTMMAKE SURE A-0 SWITCH IS ON 0"
70 INPUT"NUMBER TO DIAL";N$
80 IFLEN(N$)O7THEN70
90 POKE64784,(PEEK(64784)OR64)
100 PORI=1TO500:NEXT
110 POKE64784,(PEEK(64784)AND191)
120 FORI=1TO500:NEXT
130 FORI=lTO7:N=ASC(MID$(N$,I,l))-48
140 IFN<0ORN>9THEN200
150 IFN=0THENN=11
160 R=INT((N-1)/3):C=N-1-R*3
170 SOUNDl,NC(C),5:SOUND2,NR(R),5
180 FORT=1TO50:NEXTT,I
190 PRINT"DIAL COMPLETE":G0TO220
200 PRINT"INVALID NUMBER"
210 VOL0:POKE64784r(PEEK(64784)OR64):END
220 OPEN1,2,0,CHR$(22)+CHR$(5)
230 GET#1,A$:IFA$O""THENPRINTA$;
240 GETA$:IFA$=""THEN230
250 IFA$=CHR$(171)THEN280
260 PRINT#1,A$;
270 GOTO230
280 CLOSE1:GOTO210
Line-by-Line Explanation
10 Turn on volume for tone generation.
20 Read the frequencies for columns.
30 Read the frequencies for rows.
40-50 Data for frequencies.
60 Remind the user he or she is originating the communication.
70 Receive the number to dial.
80 Check for correct length of number.
90 Hang up the phone.
100 Wait.
110 Pick up the phone.
120 Wait.
130 I points to the digits. Get the value of a digit.
140 If not a valid digit, leave.
150 A zero is the eleventh button.