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HP-9836CU programming question - dramsey - 07-25-2016 04:06 PM

I just acquired a very clean and functional HP-9836CU. It has two 1M memory boards and boots perfectly into the BASIC 2.0 ROM board I have from my Franken-9826.

The boot messages identify the machine has having "Color Graphics", which is should, but simple test programs in BASIC elicit nothing: the screen never switches from text mode to graphics mode when GINIT executes. I can manually switch by pressing the "Graphics" key on the keyboard, but it always displays a blank screen until I press "Alpha" to switch back.

In other words, I can't display anything except green text.

The only thing that occurs to me is that my BASIC ROM is version 2.0, whereas the "BASIC Graphics Techniques" manual I have is version 2.1, but even if the syntax is wrong I should at least get some sort of error from the BASIC runtime, which I'm not.

Any ideas?

(Also, if anyone knows where I can find more manuals and disks for this machine, please let me know.)