Aid in RS232 serial port communication C,C++, DOS

I need fix simple program that communicate by serial port RS232, the program writen in C and must work in DOS. the program must communicate with some equipment. The program must do two things - send string, and receive string, but do this properly, at 19200 boud rate, stable and without data loss. The programmer that will bid need knowledge and well understanding of meaning of registers of RS232 hardware, because sample program use them. Now the problem: I have sample program of RS232 communication writen in C++, but the program make problems. It communicate only with itself (on other machine), it don't send data to equipment, and to other program I wrote in VB using MS COMM control (actually send one time from 100 with data loss). I suppose that after it will communicate with vb program it also will send data to equipment, because vb program always worked well. On request I will send the source of C program and vb program. I need solution ASAP. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform DOS