Pinouts for cabling between the 9 pin COM port on a PC computer to the 25 pin programming port on the 1771-DB are as follows. A 1784-CP10 cable will work otherwise connect pin 2 to 2, 3 to 3, and pin 5 to 7. Default COM rate is 1200 BAUD, No Parity, One Stop bit.
The 1771-DB series A or series B BASIC module is simply a BASIC programming language computer with a couple of serial ports on it. One of those ports must be designated as the programming port. To program the module, any dumb ASCII terminal or computer running some type of dumb terminal emulation software may be used. Such software includes WINDOWS TERM, WINDOWS HYPERTERMINAL, PROCOM, XTALK, etc.... Programs may be developed by physically connecting this terminal to the DB BASIC module and manually entering in the line numbers and program statements. Otherwise, the BASIC program may be edited and stored in an ASCII text file, if using dumb terminal software, and then downloaded to the DB BASIC module. As far as the DB BASIC module is concerned, doing this is no different than manually typing in the program but it thinks someone is typing "really fast".
A download from the ASCII text file to the DB BASIC module is accomplished by telling the dumb terminal software to "send from ASCII text file". In order to not overrun the program port input buffer, you must set up that terminal software to either wait for some time delay after each line (carriage return) is sent out, or wait for a response character (the ">" prompt) that the DB module replies back with after it receives a carriage return, before it sends the next line out. This allows the DB BASIC module to keep up with the stream of characters being sent to it so that none are lost. Recommend Hyperterminal line delay of 250 mS. The download to the DB will not work properly otherwise.
An upload from the DB BASIC module to an ASCII text file on the computer is accomplished by putting the dumb terminal software in a "capture to ASCII text file" mode and then telling the DB BASIC module to "LIST" it's program. The DB BASIC module merely lists or prints it's program out and the terminal saves it to it's hard drive in addition to displaying it on it's screen. After this is done, be sure to edit the ASCII text file to remove any non- program related commands that will be present at the beginning and end of what was saved.
