ang@Su-Dsn (12/18/82)
I'd currently contemplating on buying a modem and would appreciate user feedback on the above. I'm not sure about the exact model number except that it supports Bell 103, Bell 212A as well as Vadic protocol. Also, in view of the recent dicussion on Hayes's smartmodem, how do they compare (in terms od intelligence and price, for eg.) ? Thanks in advance, -Peng
hsplab (12/19/82)
I am currently working with a Racal-Vadic Triple modem (model number 3451). The unit directly connects to the telephone line through a modular plug, performs auto answer, but does not support the autodial features found on the Hayes unit. Since I have not had any experience with the Hayes 1200 modem and only minimal experience with the Hayes 300 modem, I can only make comments about my experience with the RV 3451. The unit was purchased almost 6 months ago and has run reliably here. Unfortunately it took almost 3 months after I ordered the unit to get delivery. I understand that delivery is a little better now. RV offers about a 20% discount to educational institutions (I can't remember the exact figure, but its close.). To initiate a dialup the user must set one switch for either 300 or 1200 baud (the unit selects either the Bell or Vadic protocol automatically) and dial a telephone number. After the computer answers, a second switch must be flipped from manual to data mode. I tried leaving the unit in data mode and the modem apparently detects dial pulses and tries to answer inspite of the lack of a carrier. For all those who have used the Hayes unit, this sounds like a lot of human interaction. The unit has only had trouble hanging on to a carrier once in the entire time I have used the unit (I still can't figure out what happened). This is remarkable since I use the modem almost every day. The unit comes in two parts: 1) a very large transformer/power supply unit measuring about the size of two cigarette packages and 2) a modem unit about twice the size of the Hayes 300 unit. Internally, the unit is controlled by an 8039H processor and the circuitry is on two boards. There is an incredible amount of analog and digital logic in this unit: I can count at least 83 integrated circuits. A row of eight lights on the control panel monitors the line/terminal status including carrier detect. Internally there are hundreds of Berg jumpers and dip switches to select options. I have not had the heart to change any of these, although the manual seems to be rather complete in describing their functions. Incidentally, the unit rather adversely wipes out my television and the only way to turn off the unit is to disconnect it from the power line (rather inconvenient). Otherwise, I have been extremely pleased with the unit. David Chou, University of NC, Chapel Hill ....ucbvac!decvax!duke!tucc!hsplab
dholakia@umn-cs.UUCP (06/06/83)
#R:tucc:-311300:umn-cs:6900005:000:385 umn-cs!dholakia Jan 21 20:21:00 1983 Racal-Vadic makes a pulsed auto-dialer version of the Va3451. It is possible to get the older models of the 3451 retro-fitted with the auto-dialer (for $160). I have been told (although I haven't seen one) that the 3451 now comes with another switch setting on the VO/DA switch - MA for Manual Answer. The auto-dialer version of the 3451 is normally $80 more than the 3451 without.