I've got a vt420 hooked up to the Altair 8800C I've been building and most of the time it works great. Running it at 19200 baud.
The problem is that sometimes it gets into a stuck cycle where it won't type anything and I have to go into setup and choose "CLEAR COMM" so make it able to type again. It seems to be related to certain characters sent to it because it happens at the same time. If I try to boot CP/M 3.0 for example, it will beep and then nothing until I do clear comm. Or if I load a floppy exercise tool, sometimes it displays garbage characters and the same thing. It is not in hold mode because there is a light on the screen to show that. I've tried Ctrl-S/Q to make sure it isn't receiving a character like that ,but that also doesn't recover it. Just clear comm. I tried looking through the manual, but couldn't find what it is.
The problem is that sometimes it gets into a stuck cycle where it won't type anything and I have to go into setup and choose "CLEAR COMM" so make it able to type again. It seems to be related to certain characters sent to it because it happens at the same time. If I try to boot CP/M 3.0 for example, it will beep and then nothing until I do clear comm. Or if I load a floppy exercise tool, sometimes it displays garbage characters and the same thing. It is not in hold mode because there is a light on the screen to show that. I've tried Ctrl-S/Q to make sure it isn't receiving a character like that ,but that also doesn't recover it. Just clear comm. I tried looking through the manual, but couldn't find what it is.