[sdiy] Who apart from me things the whole MIDI board needs replacing ?

Brian Willoughby brianw at audiobanshee.com
Mon Jan 24 22:12:05 CET 2022


I think that POTS (Plain Old Telephone System) fits the description that I poorly expressed.

Both the electrical and communications aspects of telephone are still backwards compatible, although there are only about 20 POTS symbols, and fewer if you go back to pulse dialing. There may be some technical issues that I'm not aware of. My family had an antique wall-mounted telephone with a fixed microphone and a hand-held ear piece, but someone with knowledge of the telephone system had to modify the electronics so that it would interface with the phone system - this was in the early eighties. I wish I understood the details of what was changed with that set to make it compatible, because I was under the impression that everything was backwards compatible (until, perhaps, the late nineties when digital became the norm).

I don't think that IP counts, but mostly because I didn't describe things clearly enough. The data protocol of IP is certainly the same, but I don't think that the electrical interfaces are still compatible. In other words, I don't think that you could revive an original Xerox Alto IP interface and plug it directly into a modern network without some sort of adapter that would receive the packets over an older electrical interface and retransmit them over a modern electrical interface. MIDI doesn't have this same situation.

My point about the uniqueness of MIDI is that absolutely nothing needs to be adapted to plug the physical current loop of a 1983 synthesizer with modern MIDI gear (unless it's USB-MIDI only without a 5-pin DIN connector). The signals sent and received by the vintage gear are exactly what the modern gear is also dealing with, without any intermediate translation going on. This, plus the fact that ground loops are avoided while the gear is connected, is fairly impressive given the way that *everything* else changes every year or two, requiring replacement.

Brian


On Jan 24, 2022, at 04:50, Matthew Skala wrote:
> On Mon, 24 Jan 2022, jslee wrote:
>> IP — the published, documented IP version 4 protocol that we still use today — predates MIDI slightly. The guts have remained the same and, as far as I’m aware, compatible. Though various options and extensions have been added, and since ~1996 we’ve also had IPv6.
>> Ethernet was also commercially available in 1980, though not an IEEE standard until slightly later
>> 
>> Still, that certainly leaves MIDI in some rare and distinguished company.
> 
> If we're playing this game, the basic electrical standard for landline
> telephone service dates from the 1870s.  Pulse dialling is from the 1890s
> and I think many networks can still accept the pulse dialling signals of
> that era, even if the numbering schemes have changed and DTMF introduced
> in the 1960s is now preferred.  I still use a DTMF phone plugged into a
> cable modem; the cable modem does not do a good job of following the
> standard (insufficient ring voltage - I had to build a booster) but my
> phone, manufactured in the 2010s, would've worked on at least a 1970s-era
> North American network, and except for dialling might have worked on at
> least some 1890s-era networks.  Of course, part of the secret to that is
> just the wide tolerances - both the phones and networks are designed to
> accept a lot of variation in the things they connect to.
> 
> I think there are also some very longstanding standards in electrical
> power (voltages both in the home and for transmission lines; AC
> frequencies; phase arrangment; plug designs); but a little poking through
> Wikipedia suggests that those things have not remained unchanged or
> backward compatible quite as long as the telephone, with their current
> forms in North America mostly appearing in the early 20th Century. They're
> still in flux in some other places.
> 
> -- 
> Matthew Skala
> North Coast Synthesis Ltd.




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