mark@aoa.UUCP (Mark Reynolds) (02/26/86)
<> I am trying to find out some information on the zs ( serial ) driver on the Sun 2. What I want to do is very simple: I would like to use a tty port as an I/O port to a device that obeys hardware flow control. The device would be the DCE ( modem ) and the Sun's tty port would be the DTE ( terminal ). If some combination of CTS DSR and CD were made logically false the DTE ( the Sun ) would shut up and cease to send; if some combination of DTR and RTS were made false the DCE would shut up and cease to send. From the Sun's point of view these telling the DCE to shut up would be conditioned on the zs silo being full and/or inability of the software to eat characters as fast as they are coming in. The goal is that the device is uncontrollably shipping completely arbitrary bytes at 9600 baud ( but never more than 8K ). I want to prevent any lost bytes. I am sure this has been discussed before. I do not have source, nor do I have a hardware manual for the zs. What I think I have learned so far from poking around in various places is: 1) There are an extremely large number of ioctls that may or may not apply to ttys in <sys/ioctl.h>. Some do obvious and verifiable things ( TIOCCDTR and TIOCSDTR for example ), others are obscure. Most do not seem to be documented in any documentation I have. 2) Poking around the zs includes in /sys/sundev would seem to indicate that the zs device has a mode in which it uses hardware flow control ( ZSWR3_AUTO_CD_CTS bit ); 3) Looking at the terminal line during both inbound and outbound transfers shows that only TxD, RxD, and DTR are active. My question is, can a tty device be put in a mode which uses hardware flow control? If so, how? If not, what other alternatives are available? Please help; this is quite important. To qualify my question, let me say I am a Sun novice. I have been around UNIX for quite a while, and I THINK I understand the RS232 so-called standard. Please feel free to flame my ignorance and/or stupidity. Thank you in advance. Please mail responses to me. I will summarize if interest warrants. Mark Reynolds @ ( Adaptive Optics Associates ) { wjh12 | mit-vax } ! biomed ! aoa ! mark { decvax | linus | ima | ihnp4 } ! bbncca ! aoa ! mark