since most internal phone line modems are presented to the computer as a standard serial port there tends to be no need whatsoever to have direct bus access to a rom.

Yeah, I guess there's no x86 code to execute from the firmware, it's internal code... but then we got winmodems to fog things up, but I guess they just put it all in the drivers.

winmodems were mostly DSP-like hardware where the firmware got loaded by the drivers and the cpu of the mainboard had to do the rest of the processing.
most of them were bloody horrible devices.

Old serial modems sometimes have another interesting feature.
The "voice" models allow for playing back wave form samples.
This was intended for the use as an answering machine,
but maybe this could be useful for other things, too? 🙂

Yes, could be got on internals too though. My wife's PC when I met her had this not full length, but long ISA card with a soundcard and voice modem semi integrated, they still seemed to have separate sound chips though. There was only some clunky win95 software for it for answering machine services. I don't know if a lot of those implementations were proprietary or something, but there never seemed to be a consumer piece of software that tied all the functions together in a good way, you just seemed to have these halfass apps written by ppl who were used to shoving bits down serial connections and not a lot else. Also it seemed voice modem stuff never really carried over into good win98 support, and voice modems seemed to die out before 56k.

I had some odd convos on about half a dozen forums, bulletin boards and lists dedicated to linux telephony about a decade ago, thinking that there must be some way to use them in linux, they all went about like...
Me: So I have this voice modem with answer function so it works as an answering machine...
Them: no it can't
Me: really it does it's got built in sound features which...
Them: that only came out a couple of years ago on the XB2864whatever PBX
Me: I don't need a PBX I just want digital voicemail on...
Them: yeah so you need a PBX system
Me: Right, okayyyy, so if I put a bunch of voice modems into a linux box...
Them: No, a real PBX
Me: but the modem has voice and answering features I want to use on linux.
Them: No it doesn't.

Never looked much into it, though also pondered about if it was possible to use as voicemail/number logging.
Seems like there's a whole wiki page... https://en.wikipedia.org/wiki/Voice_modem_command_set
the number logging for ISDN was easy. for analog lines it seemed like my local operator didn't support it so that option went down the drain due to not supported... Wondering if it there even was a modem that supported it on analog lines. I think there was a way, though, yeah, hardly supported, I guess.
oh well.
off to read the wiki.

weedeewee wrote on 2021-07-08, 14:49:

winmodems were mostly DSP-like hardware where the firmware got loaded by the drivers and the cpu of the mainboard had to do the rest of the processing.
most of them were bloody horrible devices.

The earlier 'hardware' DSPs were potentially more interesting, things like IBM's mWave chip. That really did the processing on the card. However it was RAM (on card) + driver, not ROM based, so probably not useful for what OP has in mind.

dionb wrote on 2021-07-09, 19:26:

The earlier 'hardware' DSPs were potentially more interesting, things like IBM's mWave chip. That really did the processing on the card. However it was RAM (on card) + driver, not ROM based, so probably not useful for what OP has in mind.

indeed. 😀

I still have the USrobotics modem bought in the 90s in its box somewhere, it could work on its own to store voice and fax messages on flash memory while the computer was off.
It might have been possible to use it as an automatic answering machine offering multiple choices to the caller as well as listen to voice messages remotely...

lolo799 wrote on 2021-07-09, 19:47:

I still have the USrobotics modem bought in the 90s in its box somewhere, it could work on its own to store voice and fax messages on flash memory while the computer was off.
It might have been possible to use it as an automatic answering machine offering multiple choices to the caller as well as listen to voice messages remotely...

US Robotics Sportster Message, I think was the model you're referring to.

Something like that yes, Message Plus maybe, it was possible to upgrade the flashrom to support whatever happened between the two competing standards at the time.