| |
Dano
Registered: Jul 2004
Posts: 234 |
Any not allowed chars for directory (art)/directory listing?
Maybe i was too blind, but i could not find a resource of allowed or not allowed chars with directory listings.
I am currently working a some better screen fader. For that i would need some free chars in the rom font (copied to ram), that i could overwrite with own content. Or are all (petscii) chars allowed? |
|
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
not sure what the question is... chars that can occur when listing a directory? then the answer is: any that can occur in a basic program. that pretty much means: all |
| |
Dano
Registered: Jul 2004
Posts: 234 |
Yes that was the question.
Yet weren't there some chars which cause a special behaviour? I guess some used in the dirart compo for changing colors or altering the output could be sort of misused?
Is there any reference on those special chars and what they produce? |
| |
Ninja
Registered: Jan 2002
Posts: 411 |
You mean something like this?
http://unusedino.de/ec64/technical/aay/c64/chrstabu.htm |
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
thing is, with some trickery (eg inserting shifted space into the filename)you can make control chars - like revers on - which then allows to admit all (not sure, but that would be my guess) the chars that cant be used in normal filenames. the real question is what exactly you want to do, what kind of "not quite exactly like BASIC LIST output" is acceptable, and how you want to deal with control chars that you cant display as control chars (think CLRSCR) |
| |
Dano
Registered: Jul 2004
Posts: 234 |
it's not about altering a directory listing but clearing the screen nicely without the chars on the screen changing their content.
i made it work with pure petscii but i will give it a go with some dithered chars. let's see what will look nicer. :)
just need some 8 chars usually not used/displayed on screen before running a demo. |
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
that sounds like flawed thinking. obviously when you are doing a "fade from BASIC screen" effect *any* char can be there, regardless what kind of chars are allowed in a directory listing. |
| |
Tao
Registered: Aug 2002
Posts: 115 |
If you're making a full disk demo you can just make the dirart yourself, and thus avoid the issue of having to worry about finding a subset--you just decide on a subset of your own :P |
| |
Compyx
Registered: Jan 2005
Posts: 631 |
Quoting danoclearing the screen nicely without the chars on the screen changing their content
That would be quite a trick. If only... |
| |
ChristopherJam
Registered: Aug 2004
Posts: 1409 |
Quote: that sounds like flawed thinking. obviously when you are doing a "fade from BASIC screen" effect *any* char can be there, regardless what kind of chars are allowed in a directory listing.
Clearly the thing to do is to analyse the screen at runtime, counting the number of occurrences of each char and using the eight that appear least often :D
Alternately, replace any commas onscreen with full stops, and any semicolons with colons, same for reverses of both - that gives you four free. Then there are the two spare spaces at 96 and 224, thats two more. Oh, and turn zeros into capital Os. Done :D |
| |
soci
Registered: Sep 2003
Posts: 480 |
Use this replacement table for uppercase:
67 -> 64
93 -> 66
96 -> 32
106 -> 103
116 -> 101
195 -> 192
221 -> 194
224 -> 160
234 -> 231
244 -> 229
And this for lower case:
96 -> 32
106 -> 103
116 -> 101
222 -> 102
224 -> 160
230 -> 94
234 -> 231
244 -> 229
Therefore you can always get at least 8 chars to play with without changing the displayed content. |
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
now thats interesting... are those the few cases that were "fixed" from the original thin pet/vic charset? |
| |
soci
Registered: Sep 2003
Posts: 480 |
Yes, these are the result of the widening "fixup". The original only had the shift space as duplicate. |
| |
Dano
Registered: Jul 2004
Posts: 234 |
soci, that helps alot! |
