Re: serial performance
Trifle Menot <[email protected]>
| Newsgroups | org.kernel.vger.linux-msdos |
|---|---|
| Message-ID | <[email protected]> |
On Sat, 13 Mar 2010 07:39:00 +0000, Paul Crawford <[email protected]> wrote: >Trifle Menot wrote: >> With that setting, PCBoard now sees a 16550 when using /dev/ttyS0, and >> my remote output looks fast, like 57600 should. So poking the necessary >> bits into the dosemu virtual UART fixed things up. >Can you elaborate on which bits you poked to achieve this? >We have also had some performance issues with the virtual UART and >anything that makes it more like real-time would be appreciated. I'm not sure, but probably UART FCR0=1. I got the idea from reading PCBoard's help text for the "Force 16550A Usage" setting: > Some multi-tasking environments, such as OS/2 or Windows, use device > drivers to virtualize the comm port. In the process of doing so, they > may hide the 16550A UART, making it appear to be a 16450 UART when > accessed by a DOS application. > Setting the answer to 'Y' tells PCBoard to operate AS IF it had > detected a 16550A chip. From a quick read of the dosemu source, it seems that the virutal UART defaults to 16450 mode, until you put it into 16550 mode, presumably by poking FCR0=1 into the (virtual) UART. If the app cannot do that on its own, maybe a small C program that does it, prior to launching the app, would achieve the same result. -- Web mail, POP3, and SMTP http://www.beewyz.com/freeaccounts.php