gfs@druxu.UUCP (SkinnerGF) (08/24/84)
Thanks to all who replied to my inquiry about 1200 baud single chip
modems. Here is a summary of all I heard and read. If you know
of any not on this list, please tell me.
Many speeds are included here for completeness.
manufacturer / speed / notes
chip number(s) specification
EXAR XR-2120 300 / 1200 / 2400 $40 for the set
XR-2123 Bell 212A or 201
XR-14412 CCITT V.22 or V.26
Micro Power Systems
MP-7223 same as XR-2123
MP7224 1200 CCITT V.23
Texas Instruments 300 / 1200
TMS99542 Bell 212A, Racal Vadic 3400
TMS99531 CCITT V.22
TMS99532
TMS99533
TCM3101 1200 Bell 202, V.23
National
MM74HC942 300 complete modem
MM74HC943 Bell 103 $25 - 28
TP3310,11 122 / 600
TP3320,21 Bell 202s, V.23
AMI 300 complete modem
S3530 Bell 103, V.21
S35212 1200
S35213 Bell 212A
Rockwell Intl.
R5312 1200
R5313 Bell 212, V.22
Motorola
MC145445 300 Bell 103,113 for use on noisy lines
MC6172 2400 / 1200
MC6173 Bell 201B/C, V.26
MC6862 2400 / 1200 Bell 201B/C, V.26
OKI Semi. 1200 $16 in large quan.
MSM3953AS CCITT V.21, V.23
Silicon Systems 1200
SSI 223 CCITT V.23
Signetics up to 2Mbits/sec 2 wire FSK
NE8050,1 FSK (similar to Ethernet)
REFERENCES:
Integrated Ckts Mag Jul/Aug 84 p11 A comparison of various chip sets
Electronic Design Dec 22, 83 p111 A look at standards
Electronic Products Jan 14, 84 p59 A guide to modem ICs
Electronic Design Aug 4, 83 p123 NE8050,1
Electronic Design Jun 14, 84 p261 TMS99532, etc...
Electronic Design Jan 12, 84 p325 MC6172,3
EDN Jun 9, 83 p75 Cermetek CH1760 212A modem hybrid module
and some small single board 212 modems
Electronics Jan ?, 83 TCM 3101
VERY good data is available from EXAR and from Micro Power Systems.
Note that the modem chips can easily be connected to a phone line
by using one of the new single chip telephone circuits. These
will allow DTMF signaling etc.. A pretty smart modem could be made.