Telnet has never worked properly on my physical HP3000. I never needed it so I never fixed it. I decided to to track down the problem this evening.
Fixing the telnet server was fairly easy – in 2001 someone altered the Telnet Security settings to Deny *.*.*.* so no one was going to get in. Which made sense when it was in production. Now, this system runs maybe 4 hours a year and has nothing of value on it, so telnet is acceptable!
Once I had the telnet service running I found that accessing it from a Linux shell worked just fine but for some reason echo was failing when I accessed it with puTTY.
The logical answer was to change Local Echo from Auto to Forced On. Except when you do that, passwords are echoed.
The correct answer is to set Local line Editing to Forced Off:
Now, each character is echoed back from the host so passwords are not shown:
: :hello manager.sys ENTER ACCOUNT (SYS) PASSWORD: ENTER USER (MANAGER) PASSWORD: HP3000 Release: C.65.00 User Version: C.65.00 FRI, DEC 18, 2020, 11:10 PM MPE/iX HP31900 C.25.06 Copyright Hewlett-Packard 1987. All rights reserved.