On Fri, 19 Mar 2004 16:48:33 +0100, Meindert Sprang wrote:>> RS-232 ports were dropped from the PC specification in 2000 (and they >> started disappearing from Macs before that). Essentially, they're >> obsolete.That should be "obsolescent", to be more accurate.>Nonsense. ALL industrial PCs are still equiped with com ports. Because a >whole bunch of rock-solid industrial protocols run on RS-232.That may be true, but it doesn't mean they're in some way *required* to have them. I would assume the industrial PC makers are quite aware that many of their users particulary require RS-232 ports, so naturally include them. Have you actually read the "official" PC2000 specification? The document is still available on both Microsoft's and Intel's websites, last I looked. It clearly states that a Wintel "PC" is *not* required to have RS-232 ports - they're optional, unlike USB. Since Wintel have proclaimed they're not required, increasing numbers of mobo makers (often using Intel chipsets) are leaving them out, particularly in budget machines. Some research in the US around the turn found that less than 1% of all RS-232 ports on PCs had anything plugged into them. Given the obvious advantages of USB, the switch made sense for the average joe. (BTW, I think I'd be looking at differential signalling if I wanted rock solid performance, particularly in an industrial environment. RS-232 has cruddy noise immunity.)>> >For us embedded engineers who have developed uC products that communicate >> >with PCs through COM ports, this situation is getting scary. >> >> Why? We've all known about this for at least four years now - that's >> surely enough time to come up with an alternative strategy. > >Why? What exactly is wrong with a simple, cheap serial port?Apart from the ridiculous interrupt overhead in any modern OS, you mean? A 16-byte FIFO is just inadequate, especially if using the port at or near it's maximum speed. Another reason is the pressure on space within the standard ATX interface panel cutout. You can easily get 4 USB ports in the same space as a 9-pin "D", for example.>It's only the >fault of the current game-driven PC industry that serial ports become >obsolete on mainstream PC's. I don't see any real technical reason why >serial ports should disappear.There was no technical reason why they had to disappear from the Mac either. But why equip all PCs with an interface that very few people use? What's wrong with progress, anyhow? RS-232 is already well past retirement age. Let it die in peace, I say. USB is a vast improvement. -- Max
Demise of the COM port?
Started by ●March 18, 2004
Reply by ●March 19, 20042004-03-19
Reply by ●March 19, 20042004-03-19
Grant Edwards <grante@visi.com> wrote in news:405b1dc6$0$175$a1866201 @newsreader.visi.com:> On 2004-03-19, Meindert Sprang <mhsprang@NOcustomSPAMware.nl> wrote: >> "Max" <mtj2@btopenworld.com> wrote in message >> news:noul50hqvd6a3u58orkm4tokk4jbgssn8d@4ax.com... >>> >>> RS-232 ports were dropped from the PC specification in 2000 (and they >>> started disappearing from Macs before that). Essentially, they're >>> obsolete. >> >> Nonsense. ALL industrial PCs are still equiped with com ports. Becausea>> whole bunch of rock-solid industrial protocols run on RS-232. > > In addition to USB and Ethernet attached serial ports, there > are still plenty of PCI serial boards available. Who in their > right mind would by a slotless PC as an embedded systems > development host? > > Sheesh, you can by a 2GHz machine with half a gigabyte of RAM a > quarter terabyte of disk space and a graphics board that does > 3D shading in hardware for a grand total of $1000! And people > are whinging because they've got to spend $20 for a serial > port. > > Kids these days.... ;) >Actually, the most annoying problem I have is with the newer notebook computers. I like to use notebooks in test cells because they take up a lot less space on the bench. This is a great use for older notebooks that are fairly useless for anything else. I also travel with dev tools some of the time. I use an USB to serial cable I bought from Saelig that uses an FTDI chip. We use the FTDI chips in many of our products so this is convenient from a device driver point of view. As I said before, I think the upcoming problem will be with the Parallel Port since these are most always bit banged when used as programmer interfaces. Oh well..... -- Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- comp.dsp conference July 28 - Aug 1, 2004 details at http://www.danvillesignal.com/index.php?id=compdsp email: compdsp@danvillesignal.com Who says you can't teach an old dog a new DSP trick?
Reply by ●March 19, 20042004-03-19
Meindert Sprang <mhsprang@NOcustomSPAMware.nl> says...>What exactly is wrong with a simple, cheap serial port?The new PCs don't have them. I started using 10/100BaseT ethernet instead of serial on all my industrial robotics designs and USB instead of serial on my consumer designs years ago. -- Guy Macon, Electronics Engineer & Project Manager for hire. Remember Doc Brown from the _Back to the Future_ movies? Do you have an "impossible" engineering project that only someone like Doc Brown can solve? My resume is at http://www.guymacon.com/
Reply by ●March 19, 20042004-03-19
Max <mtj2@btopenworld.com> says...>What's wrong with progress, anyhow? RS-232 is already well past >retirement age. Let it die in peace, I say. USB is a vast improvement.Next thing you will be telling me that I should be using this newfangled "World Wide Web" rather than good old fashoined Gopher Servers... -- Guy Macon, Electronics Engineer & Project Manager for hire. Remember Doc Brown from the _Back to the Future_ movies? Do you have an "impossible" engineering project that only someone like Doc Brown can solve? My resume is at http://www.guymacon.com/
Reply by ●March 19, 20042004-03-19
On 2004-03-19, Meindert Sprang <mhsprang@NOcustomSPAMware.nl> wrote:> Why? What exactly is wrong with a simple, cheap serial port?What's wrong is they're not simple, and they're not cheap. Plugging RS-232 stuff together has never been simple: I've been using RS-232 stuff for 20 years, and I have collected big drawer of cables and adapters -- and I _still_ never have the right combination of connector-size, connector-gender, and DTE/DCE. And then there's the whole bit/baud/parity/flow mismatch circus. As far as cheap: DB-9 (and especially DB-25) connectors are expensive both in parts cost and board-space. When you consider the fact that virtually nobody _uses_ them, it would be a foolish decision (from both a financial and engineering view) to include them in new designs. Not that I don't want/need serial ports on my computers (I do), but I'm able to differentiate between what _I_ want and what would be a good decision overall. -- Grant Edwards grante Yow! - if it GLISTENS, at gobble it!! visi.com
Reply by ●March 19, 20042004-03-19
USB offers auto device detection and driver installation, Hot swapping (which admittidly you can do with RS232, but end users are typically told not to), Higher data rates, Easier to use connector (no thumb screws) Less bulky connector comparted to DB-25 and DB-9's that they replace Forgetting how well these features ACTUALLY work, vs. how well they were INTENDED to work, USB is significantly better for the typical dumb PC end user. What exactly to PC games have to do with the demise of the COM port? -J> Why? What exactly is wrong with a simple, cheap serial port? It's only the > fault of the current game-driven PC industry that serial ports become > obsolete on mainstream PC's. I don't see any real technical reason why > serial ports should disappear. > > Meindert
Reply by ●March 19, 20042004-03-19
On 2004-03-19, Mood <U_JMood@umassd.edu> wrote:> What exactly to PC games have to do with the demise of the COM port?PC games and MS Office/IE/OE are the reasons people buy PCs. None of them requires COM ports. Nobody wants to pay for stuff they don't need. The percentage of people like me who want need RS-232 async ports is, as they used say in pysics class, "sufficiently close to 0". -- Grant Edwards grante Yow! .. I want a COLOR at T.V. and a VIBRATING BED!!! visi.com
Reply by ●March 19, 20042004-03-19
"Meindert Sprang" <mhsprang@NOcustomSPAMware.nl> wrote in message news:<405b16d6$1@news.nb.nu>...> "Max" <mtj2@btopenworld.com> wrote in message > news:noul50hqvd6a3u58orkm4tokk4jbgssn8d@4ax.com... > > > > RS-232 ports were dropped from the PC specification in 2000 (and they > > started disappearing from Macs before that). Essentially, they're > > obsolete. > > Nonsense. ALL industrial PCs are still equiped with com ports. Because a > whole bunch of rock-solid industrial protocols run on RS-232. > > > >For us embedded engineers who have developed uC products that communicate > > >with PCs through COM ports, this situation is getting scary. > > > > Why? We've all known about this for at least four years now - that's > > surely enough time to come up with an alternative strategy. > > Why? What exactly is wrong with a simple, cheap serial port? It's only the > fault of the current game-driven PC industry that serial ports become > obsolete on mainstream PC's. I don't see any real technical reason why > serial ports should disappear.That's just silly. Serial ports are going away on mainstream desktops because the vast majority of users never connect anything to them anymore. Even if they only cost a couple of bucks to add, why? For the convenience for the few percent (and I'd bet that percentage is in the middle single digits, and heading south fast) of users who have a serial device to attach to their PC? Just what do you think "mainstream" users might actually attach to a serial port? I'll give you Linux users wanting an external modem (although USB support on Linux is a lot better these days). And of those few users, the vast majority's needs are perfectly satisfied with a $20 USB->RS232 adapter, or a similarly priced PCI card? ISA slots are gone from standard desktops too, floppies are not long for this world, neither are parallel ports, and you can't bit-bang I/O ports without a device driver on current desktop OS's either. Deal with it. If you want to use mainstream hardware, you're going to be stuck using hardware that the mainstream wants to buy and use. And maybe there's a product in here someplace: A more intelligent USB->serial adapter without the excessive buffering delays of the "conventional" products.
Reply by ●March 19, 20042004-03-19
Max <mtj2@btopenworld.com> writes:> Some research in the US around the turn found that less than 1% of all > RS-232 ports on PCs had anything plugged into them. Given the obvious > advantages of USB, the switch made sense for the average joe.I think there's also an assumption that the typical user has upgraded to a late model OS that supports USB. If they left the serial and parallel ports alone, how else could they force the user to abandon NT?> >Why? What exactly is wrong with a simple, cheap serial port? > > Apart from the ridiculous interrupt overhead in any modern OS, you > mean?USB doesn't rank very high in software efficiency when you're using low speed devices like keyboards and mice.> There was no technical reason why they had to disappear from the Mac > either. But why equip all PCs with an interface that very few people > use?The problem with the "but very few people need them" argument is that it moves the PC away from a general purpose one-size-fits-all machine into a specialized machine. Ie, the PC was used a lot in engineering, much more than Macs, precisely because it could be adapted to a wide variety of uses. -- Darin Johnson Gravity is a harsh mistress -- The Tick
Reply by ●March 19, 20042004-03-19
Grant Edwards <grante@visi.com> writes:> As far as cheap: DB-9 (and especially DB-25) connectors are > expensive both in parts cost and board-space.The product I used always just had two or three pins rather than full connectors. Dirt cheap. The software was cheap too since driving a serial console from minimally sized boot and diagnostic code is simple Doing an ethernet console was much more expensive. -- Darin Johnson "Look here. There's a crop circle in my ficus!" -- The Tick
