11-27-2018, 12:03 AM
Have you tried a different telnet program? I have tried plenty of different PC telnet programs and some work and some drop characters like you have shown without flow control enabled. I thought you were using an 8 bit machine. 
My Apple II+ w/SCC, Apple IIc (actually a Laser 128), and my Apple IIGS all require flow control. The Laser and IIGS use DTR/DSR as flow control with their special cable. The SCC uses RTS/CTS. Without flow control, I get dropped characters at 9600 baud with all 3 machines.
My Apple II+ w/SCC, Apple IIc (actually a Laser 128), and my Apple IIGS all require flow control. The Laser and IIGS use DTR/DSR as flow control with their special cable. The SCC uses RTS/CTS. Without flow control, I get dropped characters at 9600 baud with all 3 machines.