[net.unix-wizards] Microcom 2400 BPS modem

sid@linus.UUCP (Sid Stuart) (02/06/85)

Subject: Microcom modem
Newsgroups: net.dcom,net.unix-wizards

I just got a flyer from Glasgal Communications (talk to Jeff at 617-449-7470)
about a 300-1200-2400 Bits/Sec Autodial modem with error correction. It is
made by a company called Microcom. Price is about $900. The claim is
that this modem does completely error free transmissions over a dialup
line. I don't have the details, but I think the mechanism is to do
error checking and retransmission of garbled packets. Several other companies
(Concord Data and Micom) have similar equipment, but not in this
price range.($700 for an add on box, $1500 for modem with error correction,
these are approximate figures.)

	It all sounds a little too good to be true. Are there any experts out
there that can expound on this subject with more intellegence than I can?
Has anyone every dealt with Microcom? If this equipment works, we
could most likely junk the G protocol for uucp and do straight data
transfers. This would speed transfers up a tad and lower the overhead
on my overloaded computer. The following is an abridged list
of specs on the modem.

SX2400 features

	Full synchronous or asynchronous capability
	Fallback to 1200 or 300 bps
	100% error free communications between Microcom modems and
	MNP-supported 	devices
	Storage of 9 36 diget phone numbers
	Auto-dial/Auto-answer/auto-redial
	Half or full duplex
	tone or pulse dialing
	Configuration selectable via switches or menu
	Audio speaker with volume control
	Kitchen sink
	4k CMOS RAM with 30-day NiCad backup of phone numbers and menu settings

Specifications

	CCITT V.22 bis compatible at 2400 BPS
	V.22 A and V.22 B at 1200 BPS
	Bell 103 compatible at 110-300 BPS and 212A compatible at 1200 BPS

Line requirements
	
	Voiceband, 2 wire general switched telephone network

Protocol Features

	Microcom Networking Protocol (MNP) when communicating with other
	Microcom modems or MNP supported devices provides:
	error-free transmission between modems. Error detection by
	cyclic redundancy check (CRC-16), Byte oriented framing and
	transparency (asyncronous mode)

Interfaces

	EIA RS-232C, CCITT V.24/V.28 interfaces for local device
	up to 9600 bps, bi-directional
	XON/XOFF or hardware flow control
	Two rj11C connectors for telephone and telephone lines.

Note, all of the above information does not constitute an
endorsment of this product by myself or the MITRE Corp. and
is probably filled with mistakes dues to the clumsiness of my
tired little fingers.

	
				sid at linus

(imagine a cute message here)