Which internal modem can I use?

[Uwe Kotyczka]

Hope this is not OT, if you know a better group let me know.

I want to use an old PII computer and wish to install a 56k
internal modem. So I bought a PCI modem at ebay for cheap
and plugged it in. It was no problem to find the correct driver.

However when starting dialing I am reported that the modem
will not work because it requires extended MMX instruction sets,
which is not supported by the CPU.
CPU is an AMD K5.

So I guess that those two hardware components will not work
together.

Now my question is: Are there any 56k modems (either PCI or ISA)
which will work with the AMD K5? Where to get information about
this? And, if so, where to get such a modem for cheap?

Any help appreciated. TIA, Uwe.

 

[Never anonymous Bud]

Trying to steal the thunder from Arnold, (e-mail address removed) (Uwe Kotyczka) on 20 Oct 2004 03:59:45 -0700 spoke:

Now my question is: Are there any 56k modems (either PCI or ISA)
which will work with the AMD K5? Where to get information about
this? And, if so, where to get such a modem for cheap?

Any ISA modem should work, or an external.

 

[Franc Zabkar]

Hope this is not OT, if you know a better group let me know.
comp.dcom.modems

I want to use an old PII computer and wish to install a 56k
internal modem. So I bought a PCI modem at ebay for cheap
and plugged it in. It was no problem to find the correct driver.

However when starting dialing I am reported that the modem
will not work because it requires extended MMX instruction sets,
which is not supported by the CPU.
CPU is an AMD K5.

So I guess that those two hardware components will not work
together.

Now my question is: Are there any 56k modems (either PCI or ISA)
which will work with the AMD K5? Where to get information about
this? And, if so, where to get such a modem for cheap?

Any help appreciated. TIA, Uwe.

Get yourself a "full hardware" or "controller based" ISA or PCI modem.
Avoid controllerless or "soft" modems. Having said that, PCI hardware
modems are rare. USR's 5610 and Multitech's ZPX are the only examples
that come to mind. OTOH, ISA modems are equally as good and are
plentiful. Best Data's current model 56SF92WB, Conexant ACF3 chipped,
controller based, ISA modem sells for around $20.


- Franc Zabkar

 

[Arno Wagner]

Hope this is not OT, if you know a better group let me know.

I want to use an old PII computer and wish to install a 56k
internal modem. So I bought a PCI modem at ebay for cheap
and plugged it in. It was no problem to find the correct driver.

However when starting dialing I am reported that the modem
will not work because it requires extended MMX instruction sets,
which is not supported by the CPU.
CPU is an AMD K5.

A "soft-modem" also Winmodem. This is crippled hardware that
cannot do a simple job. The cost savings is small. My personal
suspicion is that Microsoft pays/coerces companies to produce
this type of modem since they are mostly unusable with other
operating systems.

So I guess that those two hardware components will not work
together.

Now my question is: Are there any 56k modems (either PCI or ISA)
which will work with the AMD K5? Where to get information about
this? And, if so, where to get such a modem for cheap?

There are such modems. In fact that used to be the norm. ISA is
perfectly fine for such a modem. A good sign that you get a real modem
is if it runs under Linux. Best check with google what people say
about a specific model before buying.

Also an external (serial) modem can only be a real modem and
not one of the crippled MS-only products since there is not enough
bandwidth in the serial bus to do the signal proccessing in the PC.

Arno

 

[Tony Hill]

Hope this is not OT, if you know a better group let me know.

I want to use an old PII computer and wish to install a 56k
internal modem. So I bought a PCI modem at ebay for cheap
and plugged it in. It was no problem to find the correct driver.

However when starting dialing I am reported that the modem
will not work because it requires extended MMX instruction sets,
which is not supported by the CPU.
CPU is an AMD K5.

So I guess that those two hardware components will not work
together.

Now my question is: Are there any 56k modems (either PCI or ISA)
which will work with the AMD K5? Where to get information about
this? And, if so, where to get such a modem for cheap?

Find an old, second-hand ISA modem. It'll work fine. PCI modems
usually (almost always) offload most of the processing normally done
on the modem onto your main processor. For someone with a 3.0GHz P4,
that really doesn't make one lick of difference, however on your
system it would pretty much grind the computer to a halt.

ISA modems, on the other hand, just can't work that way because the
ISA bus is complete and utter crap. As a result, if you get an ISA
modem it has to have the full processing capability built right on the
modem itself. Same goes for a serial-port external modem (I don't
know about USB modems, those beasts didn't exist the last time I used
a dial-up modem!)

 

[Franc Zabkar]

There are such modems. In fact that used to be the norm. ISA is
perfectly fine for such a modem. A good sign that you get a real modem
is if it runs under Linux. Best check with google what people say
about a specific model before buying.

Linux supports many "soft" and controllerless modems. A better
indicator of a hardware modem is whether it runs under DOS. A
definitive test is to check whether the modem has an
OTPROM/EPROM/EEPROM chip and an SRAM. The former holds the firmware
and usually has a part number such as 27xxxx or 28xxxx or 29xxxx. The
static RAM has a part number such as 61256 or 62256, and is sometimes
hidden underneath the EEPROM. Its function is to provide support for
error correction and data compression (and possibly other things).


- Franc Zabkar

 

[Franc Zabkar]

On 20 Oct 2004 03:59:45 -0700, (e-mail address removed) (Uwe Kotyczka)
wrote:

Find an old, second-hand ISA modem. It'll work fine. PCI modems
usually (almost always) offload most of the processing normally done
on the modem onto your main processor. For someone with a 3.0GHz P4,
that really doesn't make one lick of difference, however on your
system it would pretty much grind the computer to a halt.

A controllerless modem has minimal impact on the host CPU. OTOH, a
"soft" modem may load it down somewhat.

ISA modems, on the other hand, just can't work that way because the
ISA bus is complete and utter crap. As a result, if you get an ISA
modem it has to have the full processing capability built right on the
modem itself.

In the past I've been stung by two Rockwell/Conexant RPI modems
(2400bps and 14.4Kbps). These were hardware modems in the sense that
they looked like a standard COM port and worked fine in DOS.
Unfortunately they did not have a static RAM chip and therefore had to
rely on the host to perform error correction and data compression. I
don't know if 56K RPI (Rockwell Protocol Interface) modems ever
existed, though.

Same goes for a serial-port external modem (I don't
know about USB modems, those beasts didn't exist the last time I used
a dial-up modem!)

IME, most USB modems are controllerless. "Soft" USB modems also exist.


- Franc Zabkar

 

[Tony Hill]

A controllerless modem has minimal impact on the host CPU. OTOH, a
"soft" modem may load it down somewhat.

Remember this is a K5 we're talking about here, the fastest K5 ever
made only clocked to a bit over 100MHz and wasn't much faster (and
perhaps even slower for this sort of work) than a Pentium of the same
clock speed. Not exactly a high-end computer system. Even a
controllerless modem will probably make a dent in performance.
Besides which, last I looked, controllerless modems were a thing of
the past, they are all soft-modems these days.

In the past I've been stung by two Rockwell/Conexant RPI modems
(2400bps and 14.4Kbps). These were hardware modems in the sense that
they looked like a standard COM port and worked fine in DOS.
Unfortunately they did not have a static RAM chip and therefore had to
rely on the host to perform error correction and data compression. I
don't know if 56K RPI (Rockwell Protocol Interface) modems ever
existed, though.

To the best of my knowledge, no. I think the last of them were 28.8
modems. The whole idea of those RPI modems was that they used to
require two chips to make a modem, a microcontroller and a DSP-ish
type of chip. The RPI modems dropped the microcontroller part to save
cost, offloading that to software. By the time 28.8kbps modems
started becoming the norm it was becoming feasible to combine these
two chips into one so there was no longer any real price advantage in
those "controllerless" modems. Instead they went for the pure-soft
modems that offloaded both the microcontroller and DPS tasks onto
software.

 

[Franc Zabkar]

Remember this is a K5 we're talking about here, the fastest K5 ever
made only clocked to a bit over 100MHz and wasn't much faster (and
perhaps even slower for this sort of work) than a Pentium of the same
clock speed. Not exactly a high-end computer system. Even a
controllerless modem will probably make a dent in performance.

At worst, the performance penalty for controllerless modems is about
10%. Most of the CPU intensive work is done by the modem's own DSP, so
a K5 will probably handle it OK.

Besides which, last I looked, controllerless modems were a thing of
the past, they are all soft-modems these days.

Not true. With respect, it's clear you do not understand what a
controllerless modem is. Here is my take on the subject.

There are three types of internal modem, "soft", controllerless, and
"hard" (controller based). Softmodems have a DAA (telephone line
interface), controllerless modems have a DAA and DSP (digital signal
processor), and "hard" modems have a DAA, DSP, and controller.

Among other things, a modem's controller handles AT command parsing,
UART emulation, data compression and error correction. These functions
do not impact significantly on the host CPU. OTOH, the functions of a
DSP are highly CPU intensive, so a softmodem (which emulates the DSP
in software) may impact noticeably on CPU performance.

Examples of softmodem chipsets are PCtel HSP, Motorola SM56,
Smartlink, and Conexant HSF. Controllerless examples include Conexant
HCF, Intel HaM, Lucent Win Modem, and USR Winmodem.

Note that the term "Winmodem" is a USR trademark and refers to
their line of controllerless modems.

To the best of my knowledge, no. I think the last of them were 28.8
modems. The whole idea of those RPI modems was that they used to
require two chips to make a modem, a microcontroller and a DSP-ish
type of chip. The RPI modems dropped the microcontroller part to save
cost, offloading that to software.

Not true. Take it from me, I've had *two* of these modems. Firstly
there is nothing "DSP-ish" about the datapump chip - it is a real DSP.
Secondly, the microcontroller is still present in RPI modems. As I
stated previously, an RPI modem differs from a non-RPI modem in only
one chip, a static RAM. The modem is still controller based.

By the time 28.8kbps modems
started becoming the norm it was becoming feasible to combine these
two chips into one so there was no longer any real price advantage in
those "controllerless" modems. Instead they went for the pure-soft
modems that offloaded both the microcontroller and DPS tasks onto
software.

See above.


- Franc Zabkar

 

[Franc Zabkar]

ISA modems, on the other hand, just can't work that way because the
ISA bus is complete and utter crap. As a result, if you get an ISA
modem it has to have the full processing capability built right on the
modem itself.

Motorola SM56 ISA/PCI softmodem:
http://www.modem-help.co.uk/chips/motsm56.html

This is the Win95 driver for a Motorola SM56 ISA Data/Fax softmodem:
http://www.motorola.com/softmodem/public_download/Legacy/ISA-BUILD671.exe

PCtel ISA softmodem:
http://www.modem-help.co.uk/chips/pct388.html

USR ISA controllerless:
http://www.modem-help.co.uk/chips/usrwin.html

Ess ISA PnP controllerless:
http://www.modem-help.co.uk/chips/ess2890.html

Conexant HCF ISA/PCI/USB Controllerless:
http://www.modem-help.co.uk/chips/conhcf.html

Lucent/Agere Apollo/Luna ISA Controllerless:
http://www.modem-help.co.uk/chips/lucmar.html


- Franc Zabkar

 

[Uwe Kotyczka]

Thanks all!

I think I will try to get a ISA hard modem at eBay.
As I read this should work then.

 

[JURB6006]

First of all, your PC was not a P2 if it has a K5 in it. It must be a socket 5
or 7.

I'm kinda with you on the old PC thing. Soon I'll replace it but right now I'm
running a socket 7, I have DSL through a netcard, don't even have USB. Back
when I used dialup a hardware modem would make quite a difference.

There's a guy on eBay (if he's still there) selling these commercial ISA
hardmodems for about $7 each. These are very good modems and they support voice
and FAX, but they were in some type of equipment other than a PC and the
holddown brackets have been removed. You also need to setup a COM 3 port to use
them. They require no drivers. These are definitely commercial grade and don't
even have that lil speaker to make noise as it dials and connects. I was gettig
very good download speeds with it. In fact I bought about 10 of them and sold
them to anyone I knew with an ISA slot. I just bent up a slot cover to hold it
down.

The guy said he had thousands of them so he's probably still around. I was
considering buying a bunch of them and having the brackets made, but with
technology being how it is, it wouldn't have been a good move. There simply is
not that much of a market for anything ISA anymore.

JURB