brw@jim.odr.oz.au (Brian Wallis) (01/22/88)
A possible bug in the tty driver for Ultrix (V2.0) to do with flow control using TANDEM and CBREAK. This only occurs when reading from the device using `read(fd,&buf,1);'. I know I know, I should really read more than one character at a time. What happens in this case is that the tty driver buffer fills up to the upper limit and a ^S is sent to the sending device. When a read(fd,&buf,1) is done, the driver sends a ^Q, even though the buffer is still almost full. The sending device will start sending again and immediatly get another ^S but it will succeed in sending 2-4 characters with a net gain of 1-3 characters. When this has happened a few times, the input buffer will really overflow and characters will be lost. Is this really a bug, or have I missed something? -- Brian Wallis (brw@jim.odr.oz) (03) 562-0100 Fax: (03) 562-0616, Telex: Jacobs Radio (Bayswater) 152093 ^ What What What What What! Only 5 whats, that's not very bright!