NC200 bug in calculation for <ESC> R

[sijnstra]

Hi,
I've ported my infocom interpreter Vezza to run on NC200 under CPMish (Thanks to my requestor/tester! I don't have hardware and can't run it myself and couldn't work out how to run it on an emulator).

One of the features of the terminal I need to use is the Delete Line code, i.e. R.

It seems to be almost entirely a text line out - the line deleted starts 6 pixel rows too high (If I'm counting right that there's 7 rows per character). To get it to work properly, I've following the sequence of: Position cursor using =, move the cursor down a full text row with , then delete the row with R.

This means that I'm out by 1 pixel row after the adjustment. The result still looks strange as it leaves behind a row of "pixel dirt", so I'm hoping this can be tracked down and patched. With that I can release the customized interpreter package for the NC200.

Thanks,
Shawn

[davidgiven]

That sounds very much like a bug in the terminal emulator. That's entirely plausible, that code is terrible. The code's here if you're interested:

cpmish/arch/nc200/supervisor/tty.inc

Line 411 in 7f37cae

call tty_calculate_screen_address_of_next_line

Unfortunately I don't have a functioning NC200 any more, so unless I can make it work on an emulator there's not much I can do. Which one are you using, and what problems were you having?

[sijnstra]

Thank you! I've taken a look and I don't know enough about the internals to understand how the calculations might be out, although at first glance I can see how tightly packed in the code is, and can see what appear to be inconsistencies with how clear to EOS, Insert and delete lines use the routine tty_calculate_screen_address_of_next_line.
For the emulator, I'm using nc100em version 1.2 windows fork (haven't found a windows version of 1.3 which may work better).
I bring it up in nc200 mode (using -2 at the comment line), have the cpmish disk image present, hit INS-R and it attempts to boot but fails by eventually returning back to the main menu with the icons. A number of floppy related messages are thrown to the console as it tries, but ultimately it doesn't boot.