gfs@druxu.UUCP (06/29/84)
..... please mail me if you know who makes one. I saw an article on one recently. thanks in advance gary
hull@hao.UUCP (07/10/84)
This taken from the Motorola Microprocessors Data Manual (DL-120)
MC6862 MOS (N-CHANNEL, SILICON GATE) 2400 bps MODULATOR
2400 bps DIGITAL MODULATOR
The MC6882 is a MOS subsystem designed to be integrated into a wide range of
equipment utilizing serial data communication. The modulator provides the
necessary modulation and control functions to implement a serial data communi-
cations link over a voice grade channel, utilizing differential phase shift
keying (DKSP) at bit rates of 1200 or 2400 bps. Phase options are provided
for both the U.S. and international markets. The MC6882 can be implemented
into a wide range of data handling systems, including stand-alone modems,
data storage devices, remote data communications terminals, and I/O inter-
faces for counters. N-channel silicon-gate technology permits the MC6882 to
operate using a single voltage supply and be fully TTL compatible. The modu-
lator is compatible with the M6800 microcomputer family, and provides medium-
speed data communications capability.
* Clear-to-Send Options
* 511-bit CCITT Test Pattern
* Terminal Interfaces are TTL compatible
* Compatible Functions for 201B/C Data Sets
* 1200/2400 bps Operation
* Answer-Back Tone
Comes in 24 Pin 0.6" width package.
But a single DIP does not a modem make. The 1200 baud quad-phase di-bit
protocol used by modern modems requires fancy active filters for use on
telco's lines, what with the carbonated frogpond water they use to fill the
empty spaces.
Howard Hull
{ucbvax!hplabs | allegra!nbires | decvax!stcvax | harpo!seismo | ihnp4!stcvax}
!hao!hullhull@hao.UUCP (07/10/84)
Part 2 -the other half (I realize that this does not constitute a SINGLE CHIP
modem, but it's close) the demodulator is the Motorola MC6173, another 24 pin
0.6 inch wide DIP. The pair together now have similar part numbers, so:
MC6172 Modulator (formerly MC6862).
MC6173 Demodulator.
The MC6173 is a MOS subsystem designed to be integrated into a wide range of
equipment utilizing serial data communication.
The demodulator provides the necssary demodulation and control functions to
implement a serial data communications link over a voice grade channel,
utilizing differential phase shift keying (DPSK) at bit rates of 1200 or
2400 bps. Phase options are provided for both the U.S. and international
markets. The MC6173 can be implemented into a wide range of data handling
systems, including stand-alone modems, data storage devices, remote data
communication terminals and I/O interfaces for counters.
N-Channel silicon gate technology permits the MC6173 to operate using a
single voltage supply and be fully TTL compatible. The demodulator is
compatible with the M6800 microcomputer family, and provides medium-speed
data communications capability.
* Compatible with MC6172 Modulator
* 511-Bit CCITT V.52 Test Pattern
* Terminal interfaces are TTL Compatible
* Compatible functions for 201B/C and V.26 Data Sets
* CCITT and U.S. Phase Options
* 1200/2400 bps Operation
Ok. TTL compatibility is not RS232 compatibility, so in addition to the
active filters I mentioned in the last submission, you'll have to throw in
some RS232 14-pin line-driver receiver IC's (MC1488,MC1489). (If you want
RS422 you'll need 9836 9837 8-pin IC's.) But the real baddie is that 201B/C
(Half-Duplex) is not 212A (Full Duplex), so END GAME. Next, a look through
the IC MASTER for modem chips. [I expect a "net attack" from the tech types
on the content of this last paragraph.]
Howard Hull
{ucbvax!hplabs | allegra!nbires | decvax!stcvax | harpo!seismo | ihnp4!stcvax}
!hao!hullhull@hao.UUCP (07/11/84)
A search of the 1984 IC MASTER revealed only two DIPS (in addition to the
Motorola MC6172 and MC6173 + host of interface and active filter DIPs
mentioned in previous replies). EXAR makes a four-DIP 1200 baud Bell 212A
modulator/demodulator set:
EXAR Integrated Systems, Inc.
750 Palomar Avenue, Sunnyvale, CA 94088 Tel. 408-732-7970
XR-2120 PSK Filter
22-pin DIP, uses separately de-coupled transmit, receive, and digital power.
*On-board Crystal Oscillator with Buffered Output
*Internal Anti-Aliasing Filters
*Complete On-Board Output Active Filters
*Digitally Programmable Transmit and Receive Gains
*MODE Input Internally Switches Filters
for Answer/Originate
*Single or Split Supply Operation
*Center Frequencies Movable with Input Clock
*High Impedance Inputs(100kOhm minimum)
*Low Supply Current
*1% Center Frequency Accuracy
*Separate CLK IN and CLK OUT Pins
XR-2121 Bell 212A Modulator (1200 baud DPSK or 300 baud FSK)
18-pin DIP, requires +5v and -5v power supplies.
*Bell Standard 212A Compatible
*6-Bit Synthesized Sine Wave Output
*Internal Scrambler
*Enable/Disable Input
*1200Hz Transmit Clock Output
*Crystal Controlled with Buffered Clock Output
*External Clock Input
*CMOS/TTL Compatible Inputs
XR-2122 Bell 212A Demodulator (1200 baud DPSK or 300 baud FSK)
22-pin DIP, requires +5v and -5v power supplies.
*Bell Standard 212A Compatible
*Automatic Speed Selection in Answer Mode
*36 dB (-9 to -45 dBm) Dynamic Range Input
*On-board Descrambler
*Carrier Detect Output
*Crystal Controlled Operation
*CMOS/TTL Compatible Inputs and Outputs
XR-2125 Sync/Async Converter
14-pin DIP, single +5v supply.
*Bell Standard 212A Compatible
*Enable/Disable Inputs
*Crystal Controlled Operation
*CMOS/TTL Compatible Inputs
*9 or 10 Bit Selection
Ok. I did not find a "single DIP 1200 baud modem". When someone does make one,
it will probably have a package like the 64-pin Motorola 68000. Anybody know
(since he apparently didn't remember) what DIP gary referred to in his posting?
Howard Hull HAO/NCAR
{ihnp4!stcvax | decvax!stcvax | seismo} !hao!hullrbc@houxu.UUCP (R.CONNAGHAN) (07/13/84)
Ah! the question really is or should be: Does anyone know of single-chip 1200 Baud Bell 212A Modem, Full duplex of course. "201A: One tin can and a string..." -- Robert Connaghan Microprocessor Group AT&T Bell Labs - Holmdel, N.J. houxu!rbc
ken@turtlevax.UUCP (Ken Turkowski) (07/13/84)
Texas Instruments has just released (2 months ago) information on the
TMS9542 (TMS99533), "a 1200 BPS, single-chip, phase-shift-keyed modem
compatible with the Bell 212A, CCITT V.22, and Racal-Vadic 3400
specifications. All of the options, alternatives, and modes of
operation supported by these modems are included."
Features:
Bell 212A compatible
CCITT V.22 compatible
Racal-Vadic 3400 compatible
Originate/Answer modes
Simplex, half duplex, and full duplex capabilities
Sychronous/Asynchronous modes
Variable character length (8-11bits) in asynchronous mode
Analog loop back test mode
On-chip diagnostic and self-test mode
TTL-compatible digital serial interface
Switched-capacitor with N-channel double-poly silicon-gate MOS technology
28-pin dual in-line (DIP) package
These are preliminary specs (11/30/83) and cannot be guaranteed by
anybody, especially myself. Why, even TI isn't quite sure what to call
it (99532, 99533, 9542).
--
Ken Turkowski @ CADLINC, Palo Alto, CA
UUCP: {amd,decwrl,dual,flairvax,nsc}!turtlevax!ken