john13@garfield.UUCP (John Russell) (01/18/88)
A seemingly undocumented function of modem operation under Amigabasic is its automatic flow control -- a ^S from the other end can lock up a terminal or BBS program that's written in Basic, with no hope of recovery unless the other side sends a ^Q. This reminds me of the old PAR: <-> PRT: problems, the driver does _more_ than you want it to on certain occasions. This has only recently become a problem; a certain assh*le has decided to cause problems for a local BBS by calling in and doing this, and at 2400 baud which means not just anyone can "unlock" the system by calling in. What I would like to do is to set up a running C program that would be signalled by the Basic program, and would then print a string to the serial port. The flow control only takes effect if you write to the serial port from Basic. I have the C code for this pretty much done, aside from a few details that depend on input from the Basic program (eg what baud rate to open the serial device, is the address of the string static or passed for each write via a message). Does anyone have examples of a similar implementation, whereby a Basic program signals a task? I'm thinking in terms of how the various structures are defined, and the best way to encode data that the task might need. Since this would have to be called for every character to be echoed back it would need to be very efficient. Please send any replies dealing with the C aspect of this scheme to me (john13@garfield.uucp, ...utai!garfield!john13), and any information on an implementation of the Basic side to joseph@garfield. It's important that this be finished quickly since the board is currently not very safe from a deliberate attack via this method. John -- "Let's get those teabags outta here and replace them with some REAL Americans!" -- (Canadian) Paul Schaeffer has members of the British nobility physically ejected from the Late Night crowd