| ??? 02/19/07 18:10 Read: times |
#133261 - COM9 Limitation Demystified Responding to: ???'s previous message |
Erik said:
I am a member of the cleaning ladies trade union so I do not do windows. Well, I don't like to do Windows either, but I'm not a member of the union, so sometimes I have to. I looked into this a little further and found out what's going on. Andy said:
I beleive that it has nothing to do with serial-to-USB devices or drivers. Correct. Andy said:
As I understand it, it is completely down to lazy application developers who couldn't be bothered to work out how to properly list available ports - so they just give you an arbitrary list of 1-9. Almost, but not quite. The real problem is that a certain Windows API call, CreateFile(), magically recognizes filenames "COM1" through "COM9" as serial ports, but requires that you use a screwball syntax for COM10 and above. Here's the authoritative link: http://support.microsoft.com/?id=115831 I think we wouldn't see the COM9 limitation in so many apps if the Microsoft docs were a little clearer. As it is, you sort of have to hunt for this particular bit of information. -- Russ |
| Topic | Author | Date |
| cp2102 and multiple COM ports | 01/01/70 00:00 | |
| Depends on many things | 01/01/70 00:00 | |
| assuming USB spec is obeyed | 01/01/70 00:00 | |
| Assuming CP2102 works at 480mbps! | 01/01/70 00:00 | |
| Right, but... | 01/01/70 00:00 | |
| 921600 Baud | 01/01/70 00:00 | |
| 115.2 kbps per USB port... | 01/01/70 00:00 | |
| I do not know for sure | 01/01/70 00:00 | |
| USBExpress v Virtual COM | 01/01/70 00:00 | |
| Mindless unwarranted arbitrary restrictions | 01/01/70 00:00 | |
| COM9 Limitation | 01/01/70 00:00 | |
| what I referred to by "cheap method" was | 01/01/70 00:00 | |
| End of wrong stick? | 01/01/70 00:00 | |
| Nothing to do with serial-to-USB | 01/01/70 00:00 | |
| not the list | 01/01/70 00:00 | |
| COM9 Limitation Demystified | 01/01/70 00:00 | |
| quite | 01/01/70 00:00 | |
| Lazy? | 01/01/70 00:00 | |
Thanks guys | 01/01/70 00:00 |