Messages in this thread |  | | | Date | Wed, 2 Aug 2000 12:56:34 -0700 | | From | David Lawyer <> | | Subject | Re: [patch] DTR/DSR hardware handshake support for 2.0/2.2/2.4 |
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> Martin Schenk wrote: > > DTR/DSR is a very often used handshake for serial printers, at least > > in the POS field. A lot of supermarket cash registers are in fact PCs > > with special hardware, which for some unclear reason typically knows > > only about DTR/DSR handshaking (even if it is from other vendors: > > SNI or EPSON does not make a difference: only DTR/DSR).
Text-terminals have been using DTR/DSR flow control for decades and it's pretty much standard for them. POS terminals would be expected to use the same flow control.
On Wed, Aug 02, 2000 at 11:47:28AM -0400, Frank da Cruz wrote: > Yes, I'll second this. [Putting the DTR/DSR patch in the driver] I I'll vote for it too. > get requests for DTR/DSR (and DTR/CD) hardware flow control in > Kermit all the time for this kind of reason. The equipment involved > is not "legacy" (my least favorite word -- in common parlance it > means "not Microsoft") at all, just weird. > > There are standard APIs in SVR4 for all sorts of hardware flow control, > specified in <termiox.h> (or <sys/termiox.h>): > > ioctl(fd,command,arg) > struct termiox * arg; > > The termiox struct contains a member: > > unsigned short x_hflag; /* hardware flow control modes */ > > Which can be set to various combinations of: > > #define RTSXOFF 0000001 /* Enable RTS hwfc on input */ > #define CTSXON 0000002 /* Enable CTS hwfc on output */ > #define DTRXOFF 0000004 /* Enable DTR hwfc on input */ > #define CDXON 0000010 /* Enable CD hwfc on output */ > #define ISXOFF 0000020 /* Enable RTS hwfc on input */
Where is "DSR hwfc on output"? This is a serious omission since I think it's more important than CD hwfc.
David Lawyer
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