I would like to say a big thankyou to kb2syd for hosting that ISO. It took a day to download but works fine. But buried in the files were two little programs that have proved absolutely marvellous. See the attached photo - this is a network setup of 4 CP/M boards. 3 of them have little LCD displays, and one has a keyboard plugged in. The aim here is to build a network. The boards with 4 serial ports can act as routers, and boards can accept input from an old school serial terminal, or a terminal program on a PC (or indeed, a local keyboard).
The first board decides it wants a directory listing from the second board. It can send the characters "D" "I" "R" <CR> with a suitable typematic delay (30ms or so) and the second board responds by printing out a listing. The only problem with that is that the length of that listing is unknown, and particularly with radio, it is much more reliable to send data as packets (eg using xmodem) with proper error checking and packet resend etc.
Enter the first little program on the Walnut Creek archive, which can do a DIR and save it to a file. Then send that file using xmodem.
The second useful program is an mbasic program to chain another .com program with a save to a $$$.sub file. It is only a few lines, but this opens up huge possibilities for programs to chain each other. Writing lots of little programs that are known to work is sometimes easier than one big program. You can even save a .sub file, then chain that, and the .sub file can end by running the original program again.
Both of these programs are proving invaluable in this network experiment. So thankyou again for that archive!
! Thank you for all your efforts...:happy3: