Something that puzzles me.

[Moggy]

Bit of a strange one and not important in the grand scheme of things so just seeking some kind of explanation rather than worrying about a solution.

Over the years I have made and posted quite a few UDG conversions with no problems.

One I have tried to do for my own use but with abject failure is UDG chess, either the various 16k ones or the splendid 1k FIDE versions and yes I know about the hi-res version which for some reason I can never get to work, but really I want to design my own figures.

My problem, which manifests itself on all chess programs, is that whilst the UDGs show when the board sets up they instantly revert back to normal CHRS after the first move.
It seems that something is resetting the I register back to a default value thus showing the original characters.


Any thoughts?

[dr beep]

Which UDG-mode do you use?

I coded UDG for my Shogun with Chroma-interface.
viewtopic.php?f=4&t=4895

[mrtinb]

Maybe the chess programs shift to FAST mode when the computer thinks his next move, and then back to SLOW mode when waiting for user input. Maybe the change between FAST and SLOW resets the UDG setting.

Just a thought. I don't know if it's the answer.

[kmurta]

Changes between FAST/SLOW don't alter the I register.

I did a simple test on EightyOne with Psion Chess and ZX Chess and both kept the UDG characters, so I believe the problem is not in the programs. I just loaded an alternative UDG font and manually changed the I register (Click on the figure to see the animation):

So I would need to take a look at how you are doing this to see if I can figure out what might be going on.

[Moggy]

Thanks for the replies everyone.

I use my own UDG's designed with Andy Rea's UDG designer and run in 128 mode as I use the second set of UDGs.
I use the UDG4ZXpand board along with the ZXpand.

@Kmurta.

Kelly this is on real kit not Eighty One and as we know Eighty One doesn't always behave like the real thing so it's only real Zeddy I'm interested in and take emulator results with a pinch of salt.

My method which has worked on over 20 conversions is to first load and run a small loader program which loads the UDGs, sets them up, then the main program then off we go and as I say this works perfectly well for everything except Chess.

[kmurta]

I understand, I tested with the emulator just to make sure if the program was changing the I register, which was not confirmed. As far as I know, EO perfectly emulates the behavior of reg. I, so I infer that the problem you are experiencing is not caused directly by these chess programs.

[Moggy]

Hi Kelly.

I think I'm having some success with Super chess. I converted just one line of pawns as a test which held but turned all other characters black. I have discovered that you have to convert every character representing the pieces to it's UDG format to complete the board and any you leave untouched will produce a black square and not remain as its original character.

I will do the full conversion and report back. The new 1k FIDE versions won't convert but the original 1K chess by David Horner will convert.

Thanks again everyone who answered my question.

[Moggy]

Yes finally got it to work but it makes a mess of the menu (obviously) and the board labeling plus to honest the UDGs look a bit rubbish so yes got it to work, crossed it off my to do list now on to the next thing.