Newbie: HP-UX installation problem

I recently bought myself a HP Visualize c3750 specifically to try out HP-UX (which I have never really used), I got it with a CD set of HP-UX 11 that I boot the machine from to install.

I have no gfx adapter in the machine so I run an IBM InfoWindow II 3153 serial terminal attached to serial 1. Everything I expect to display is displayed via the terminal.

When I start up I use this guide: Installing HP-UX 11i

Everything seems fine until its time to choose terminal emulation. I started up in ibm3151 mode at first and after the initial choice of terminal I get (as you might expect) a lot of garbled text and then the installation fails when it can't determine screen size.

I configured the 3153 for VT 100 and Wyse 60 emulation but after booting and getting the "chose terminal emulation" during installation screen I can't input anything. It's very frustrating. If I switch back to ibm3151 I can input at this screen but alas that gives me garbage on the next screen before I can switch back to the correct emulation mode.

I booted the machine with a OpenBSD/hppa install ISO and that lets me chose VT 100 just fine and continue the install.

Any suggestions welcome, I'm stumped and I've googled this sideways without finding a solution.

Edit: Clarification - no matter what terminal emulation I set on the 3153 it works fine in the BIOS (forgive for not knowing the correct term for the BIOS of the machine) it's after booting HP-UX at the very first prompt that it just stops accepting input.

The correct term is <ISL>...

The subtility between an HP and IBM terminal resides on the cabling of the RS232, dont ask me how it is done...
I can only tell you that (long ago...) I remembered not having the choice and used an IBM console for an HP server, It worked after some struggling (even worked well) but the beginning of the solution was when I used the HP cable I found instead of the IBM...
So Im sure the connection to the pins differ at one point...
I am sure that the later consoles of IBM AND HP are by the same maker...

I got another nullmodem cable and tried the install with a Thinkpad T30 w/Windows and HyperTerminal as my terminal and that worked right away.

Thanks!

Unfortunately I have no time now..., but when I find some, I will try to look in my archives what modification had to be done to the cable (pin order...)... So I understand you have the original IBM cable is that so?

I have the original IBM cable for the terminal but a "generic" nullmodem cable for the Thinkpad and that last one worked right away. I don't know what the difference is but it got me through the install so I'm happy.