njm@cel (10/23/90)
I'm in the market for a modem capable of the following speeds / modulation /
compression modes: v21, v22, v22bis, v32, v42, MNP 5. For space reasons I would
prefer to be able to fit the modem inside my PC-AT. Having looked through
various brochures, I like the look of the Dowty Mayze 96 PC.
(Now the million $ questions. ;-))
Has anyone had any experience, good or bad, of this modem?
Are there similar but better modems available?
Are there any very strong reasons for not getting an internal modem?
Thanks in advance,
Nick.
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Name: Nick Mann. E-Mail: nmann@cel.co.uk nmann@cel.uucp
V-Mail: +44 442 230000 ext 3537 ..!{mcvax,ukc,uunet}!cel!nmann
"Sorry to interrupt the festivities", said Hal, "but we have a problem."
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-ronald@robobar.co.uk (Ronald S H Khoo) (10/23/90)
In article <6758@suns401.cel.co.uk> njm@cel.uucp () writes: > I'm in the market for a modem capable of the following speeds / modulation / > compression modes: v21, v22, v22bis, v32, v42, MNP 5. Why MNP 5 ? Or more to the point, why don't you specify V.42bis ? Specifying MNP 5 rather than V.42bis is probably a mistake. Specifying both might be reasonable if you absolutely need compatibility, though. > Are there similar but better modems available? The one which comes to mind is the Hayes Ultra which *does* have V.42bis as well. > Are there any very strong reasons for not getting an internal modem? Yes. Many. They are a mistake. 1) it can be damn near impossible to debug difficult connexions without the blinkenlights 2) Their serial interface is builtin, so 2a) You are at the mercy of whatever serial chips, etc they use, and its compatibility with the software you're driving it with. 2b) It's a "dumb" serial interface, so you lose significant amounts of CPU power if you're driving it at the kind of speeds that V.42bis over V.32 can give you. 2c) It uses up a whole interrupt by itself which you will curse when you come to want to add more peripherals to the PC. 2b is probably only important if you are multitasking, and together with 2c, only a disadvantage if you ever exercise the option of getting an intelligent serial card, and I suppose that's normally only an option for multiuser PC applications. But 1) is VERY important. Don't underestimate it. -- ronald@robobar.co.uk +44 81 991 1142 (O) +44 71 229 7741 (H)
bob@MorningStar.Com (Bob Sutterfield) (10/23/90)
In article <1990Oct23.063532.21901@robobar.co.uk> ronald@robobar.co.uk (Ronald S H Khoo) writes: In article <6758@suns401.cel.co.uk> njm@cel.uucp () writes: Are there any very strong reasons for not getting an internal modem? Yes. Many. They are a mistake. Your list is a good one. But if a laptop/portable user doesn't want to lug around the extra box, cabling, and power supply brick, then the convenience of an internal modem may become a more important factor. For a machine that sits on a desk, get a good serial interface card and a separate modem. For a machine that hangs from a shoulder, an internal may make sense.
pete@Octopus.COM (Pete Holzmann) (10/24/90)
ronald@robobar.co.uk (Ronald S H Khoo) writes: >In article <6758@suns401.cel.co.uk> njm@cel.uucp () writes: >> Are there any very strong reasons for not getting an internal modem? > >Yes. Many. They are a mistake. >1) it can be damn near impossible to debug difficult connexions without > the blinkenlights But on a PC, there are freebie TSR programs available that simulate the lights! >2) Their serial interface is builtin, so > 2a) You are at the mercy of whatever serial chips, etc they use, > and its compatibility with the software you're driving it with. > 2b) [Restating the same thing] True! Although (2) below sometimes eliminates this problem. Seems to depend on how the modem hardware is set up. On the other hand, there are a few significant advantages to internal modems, in certain situations: (1) Cabling is rather easy [nice for novice users] (2) [On certain modems] No hassles about hardware handshaking. The modem *knows* whether or not your program has grabbed the data. If you have a high-speed modem with end-to-end flow control, this completely eliminates the need for a fancy serial chip. (3) [Most important of all, if it applies] There are no power supply hassles. Your PC's power takes care of the modem as well. The nicest thing about a laptop is that it has a built-in UPS! Add an internal modem and you have a PC that won't go off-line when the power goes out. You also won't be stuck when you travel overseas. Rather nice. Pete -- Peter Holzmann, Octopus Enterprises |(if you're a techie Christian & are 19611 La Mar Ct., Cupertino, CA 95014 |interested in helping w/ the Great UUCP: {hpda,pyramid}!octopus!pete |Commission, email dsa-contact@octopus) DSA office ans mach=408/996-7746;Work (SMI) voice=408/985-7400,FAX=408/985-0859