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1650spec.txt
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2009-10-10
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94 lines
" "
"======================================"
" Commodore 1650 AUTOMODEM Specs"
"======================================"
" "
"Pin ID ABV Description"
"--- ---- ---- ------------------------"
" "
" "
" A - GND Ground "
" B FL2 RXD Received Data "
" C PB0 RXD Received Data "
" D PB1 RTS Request To Send "
" E PB2 DTR Data Terminal Ready "
" F PB3 RI Ring Indicator "
" H PB4 DCD Data Carrier Detect "
" J PB5 HOOK Dial / Hang Up "
" K PB6 CTS Clear To Send "
" L PB7 DSR Data Set Ready "
" M PA2 TXD Transmitted Data "
" N - GND Ground "
" "
"Note: See PROGRAMMER'S REFERENCE GUIDE"
"pages 331-332, 355, 360-361 for"
"information on accessing pins from"
"BASIC or M/L. "
" "
"Pin Descriptions "
"---------------- "
" "
"RXD - RECEIVED DATA "
"- This is the received data and is a"
"modem output signal into the C64. It"
"comes on CB1 and PB0 which are tied"
"together in the modem. "
" "
"RI - RING INDICATOR "
"- This signal is a modem output signal"
"on PB3. It is normally high(+5v). When"
"the phone rings, it goes low with each"
"cycle of the ring frequency. So for"
"each ring, it will go low about 20"
"times. It is used for AUTO-ANSWER MODE"
"to know when the phone is ringing."
"When using this mode, it is best not"
"to allow the computer to answer until"
"about one and a half rings have gone"
"through. This would be about thirty"
"ring cycles. Rings occur at about one"
"second intervals and unless a count"
"thirty is established in two seconds,"
"it is possible to get transient noise"
"to trigger the ring circuit. "
" "
"DCD - CARRIER DETECT "
"- This is an output signal to the"
"modem on PB4. This signal goes low(0v)"
"250ms after a carrier has been"
"detected. A program should be set up"
"so that no information is transferred"
"unless this signal is present which"
"means use the squelch. "
" "
"HOOK - HOOK/DIAL SIGNAL - This is an"
"input signal to the modem on PB5. When"
"this signal goes low (0v), the phone"
"line goes OFF HOOK. This line should"
"go low to answer a call or to"
"originate a call. This line is also"
"used for pulse dialing. The ratio for"
"pulse dialing should be 39ms to 61ms"
"with 39ms being OFF HOOK. Between"
"digits, there should be a wait of"
"800ms. Remember ZERO is ten pulses. "
" "
"TXD - TRANSMIT DATA "
"- This is an input signal to the modem"
"on CB2. This is the data fom the C64"
"to be transmitted out on the phone"
"line. "
" "
"These specifications courtesy of: "
" "
"Gary Farmaner 628 Trafford Cr."
"Oakville, Ontario L6L 3T5 TEL (416)"
"827-8564 "
" "
"The programmer of PRO-TERM 64 V1.3 "
" "
"This file was made by Darrell Grainger"
"on February 24, 1985 from note by Gary"
"Farmaner, and formatted into a"
"bulletin by Geoffrey Welsh."