crash@jc3b21.UUCP (Frank J. Edwards) (02/12/89)
Maybe some of you people have had experience with this and can tell me the answer: I open the serial.device (using code similar to the example in the ROM Kernel: Lib and Dev manual) for 7WIRE handshaking. I send one line's worth of data to my plotter and I get an error 13 (Ser_NoDSR). The DTR output on my plotter is run directly to the DSR pin, but I have seen this signal drop low from the plotter when it's 256 character buffer has filled up. Possibility: the plotters buffer fills up and DTR drops low; the Amiga hasn't filled it's second buffer yet, but when it does it sees that the DTR (DSR on it's end) is low and so generates the error. The flaw in this theory: I'm only writing about 18 characters before getting the error!! I am at my wits end with this thing -- anyone have any ideas? And don't suggest using xON/xOFF -- the *plotter* doesn't support it (what can I say; its an old Apple plotter [ugh!]). Thanks for any help. Frank "Crash" Edwards "Damn it, Jim, I'm a doctor, not a moon shuttle conductor!"
jms@antares.UUCP (Joe Smith) (02/15/89)
My experience with hardware handshaking is to make sure that the computer
always sees DSR and CD always high, and that CTS (Clear To Send) is used
by the device to do flow control. Have you tried creating a cable that
connects your plotter's DTR to the Amiga's CTS with the Amiga's DSR high?
--
Joe Smith (408)922-6220 | jms@antares.Tymnet.COM or jms@opus.Tymnet.COM
McDonnell Douglas FSCO | UUCP: ...!{ames,pyramid}!oliveb!tymix!antares!jms
PO Box 49019, MS-D21 | PDP-10:JMS@F74.Tymnet.COM CA license plate:"POPJ P,"
San Jose, CA 95161-9019 | narrator.device: "I didn't say that, my Amiga did!"bryce@cbmvax.UUCP (Bryce Nesbitt) (02/18/89)
In article <570@jc3b21.UUCP> crash@jc3b21.UUCP (Frank J. Edwards) writes: | |...I send one line's worth of data to my plotter and I get an error 13 |(Ser_NoDSR). Surprise! If DSR is ever low, the serial device gives that error. |The DTR output on my plotter is run directly to the DSR pin, but I have |seen this signal drop low from the plotter when it's 256 character buffer |has filled up. Connect DTR from the printer to CTS. leave the Amiga's DSR input alone. Apple uses the bizare concept of "DTR" handshake; by connecting to CTS you will be emulating "real" CTS/RTS handshake. |(what can I say; its an old Apple plotter [ugh!]). -- |\_/| . ACK!, NAK!, EOT!, SOH! {O o} . Bryce Nesbitt (") BIX: bnesbitt U USENET: cbmvax!bryce@uunet.uu.NET -or- rutgers!cbmvax!bryce Disclaimer: I'm not an official, and this is not an official opinion.