bruce@uucp (Bruce Lilly) (03/20/91)
In article <1991Mar19.045702.2004@nntp-server.caltech.edu> andy@cs.caltech.edu (Andy Fyfe) writes: > >... Is hardware flow control simply turned on >and off with the CTSCD bit in the termio control flags? Does one need >to use the mystic program in /etc? What does the program actually do? No, no, and according to the output of running strings on /etc/hfc_ctl, it does an undocumented ioctl. CTSCD only works if HFC is already on. /etc/hfc_ctl can be used, but one could also call the ioctl. strings /etc/hfc_ctl: :::::::::::::: /etc/hfc_ctl :::::::::::::: %s: error %d opening %s Usage: %s [+|-]ttyport %s: error %d on TCHFCCTL ioctl @(#) adminbin:adminbin.sl 1.137 TCHFCCTL isn't in any of the header files (at least not the ones which came with the base 3.51 or development set), but it would appear to be something like: #define TCHFCCTL (TIOC | 15) in the style of termio.h. An arg of 0/1 turns HFC off/on. There appears to be a kernel variable "hfc_dev", which seems to be a type of bit mask for tty's with HFC turned on, but the mapping isn't entirely lucid (and it doesn't do one any good unless one's program is run as a user or group which can read /dev/kmem). There's also an "hfc_csq", but I've no idea what that does. Note that unlike SVR4, one cannot have both HFC and XON/XOFF (soft) flow control. If HFC is on, XON/XOFF is disabled, and there's no easy way to determine whether or not HFC is on or off (see above). (Regarding the plan to get source for the 3b1, if we're going to do it, let's do it right and get the latest, so that some problems (like the above) can be cleared up -- and having some BSD compatibility a la SVR wouldn't hurt either (the 4.2BSD networking stuff from Wollongong is buggier than a boatload of bananas).) > >Andy Fyfe andy@cs.caltech.edu -- Bruce Lilly blilly!balilly!bruce@sonyd1.Broadcast.Sony.COM
thad@public.BTR.COM (Thaddeus P. Floryan) (03/23/91)
In article <1991Mar20.033336.23302@blilly.UUCP> bruce@uucp (Bruce Lilly) writes: > [...] >TCHFCCTL isn't in any of the header files (at least not the ones which >came with the base 3.51 or development set), but it would appear to be >something like: > >#define TCHFCCTL (TIOC | 15) > >in the style of termio.h. Strange. That definition IS in /usr/include/sys/termio.h on my systems, and the date on termio.h coincides precisely with the date I installed the 3.51 Development Set (back in 1987). I have some other comments re: hardware flow control (later this weekend) and its efficacy on the 3B1. To prevent someone turning blue from holding their breath, I'll mention quickly that I'm *NOT* pleased with how HFC functions with the 3.51m kernel. Details later. Thad Floryan [ thad@btr.com (OR) {decwrl, mips, fernwood}!btr!thad ]
bruce@balilly (Bruce Lilly) (03/27/91)
In article <2177@public.BTR.COM> thad@public.BTR.COM (Thaddeus P. Floryan) writes: >In article <1991Mar20.033336.23302@blilly.UUCP> bruce@uucp (Bruce Lilly) writes: >> [...] >>TCHFCCTL isn't in any of the header files (at least not the ones which >>came with the base 3.51 or development set), but it would appear to be >>something like: >> >>#define TCHFCCTL (TIOC | 15) >> >>in the style of termio.h. > >Strange. That definition IS in /usr/include/sys/termio.h on my systems, >and the date on termio.h coincides precisely with the date I installed >the 3.51 Development Set (back in 1987). Yep. It seems the previous owner of the machine which I do most of my software development on had an old version (1.3) of sys/termio.h -- 1.4 has it defined. Sigh -- I could have saved a lot of time with adb if the previous owner had kept the machine up-to-date. -- Bruce Lilly blilly!balilly!bruce@sonyd1.Broadcast.Sony.COM