PDQComm contains both high- and low-level communications routines that let you go far beyond what is possible using BASIC's native OPEN "COM" command alone. PDQComm was originally written for use with our P.D.Q. replacement link library, because the P.D.Q. OPEN statement doesn't support a Com port argument. Therefore, these tools are necessary to add communications when using P.D.Q. However, PDQComm is also ideal for use with regular BASIC programs, to avoid the need for ON ERROR and to add advanced features not available using BASIC commands alone. Many programmers prefer to avoid ON ERROR when possible, because of the code size and speed penalties that ON ERROR imposes.

PDQComm offers many enhancements not available in BASIC such as 16550 FIFO support, non-standard protocols, and XModem CRC, YModem, and ASCII file transfers. Other important enhancements include a unique LINE INPUT replacement that accepts a time-out value, functions to read and set the hardware lines, the ability to communicate at speeds up to 115k BPS, and much more. The timed input routine is particularly valuable because it prevents your PC from hanging if the remote terminal never sends a CHR$(13) to end the current line. PDQComm also lets you change the baud rate and other Com port parameters, even while the port is open. All of the PDQComm routines are designed to emulate the syntax of the BASIC routines they replace, to make them easier to learn and use. For example, to determine how many characters have been received and still wait to be read, you'd use the ComLoc function, as opposed to BASIC's LOC. Although PDQComm supports ports 1 through 4, only two ports may be open at one time, unless you have hardware specifically designed to operate all four ports at once.

Also included are routines that emulate ANSI, DEC VT52 and VT100, Data General D215, and generic terminals. The ANSI emulation provides all the color and cursor control abilities of ANSI.SYS, without having to waste memory loading that driver. The emulation routines can operate within a windowed area, and you can even have multiple windows active at one time. You control how the emulation routines print, specifying either direct writing to video memory for maximum speed, or through the BIOS for compatibility with other programs.

All the PDQComm routines are very small and thus add very little to the size of your .EXE files - the core routines needed for a complete terminal program add less than 2500 bytes! Compare that to the 12k compiled BASIC adds when you use OPEN "COM." Many useful examples are included, and the PDQComm documentation contains extensive tutorial information, including a complete overview of communications in general. Additional tutorials explain modems, serial cables, port parameters, and UARTs. All the important standard Hayes commands are described in detail, and each emulation also includes a table of control codes that are recognized.

The Full Moon Philosophy

As with all our products, full source code is provided at no additional cost, so you can see how the routines were designed and even modify them if you want. We genuinely want you to understand how our libraries work and be able to learn from them. All of our products are reasonably priced and include free technical assistance, but they are licensed for use by only one person using one computer at a time. Royalty payments are not required when our routines are incorporated into your compiled applications. However, you may not distribute our source, object, or library files. If your customers need to rebuild your program, they will need their own copy of our product(s).

The Bottom Line

PDQComm costs $129 and works with QuickBASIC 4.x, PDS 7.x, and VB/DOS. Add $8 for UPS ground shipping to US addresses only (no P.O. boxes); Connecticut residents must add 6.0% sales tax or show proof of tax-exempt status when ordering. Please email or call for overnight and foreign shipping costs. We accept only prepaid orders accompanied by a check.

Download Demo: PDQCOMM.ZIP (21k)