CCS64 Forum

A forum to discuss issues about CCS64!
It is currently Tue Oct 24, 2017 7:48 am

All times are UTC + 2 hours




Post new topic Reply to topic  [ 8 posts ] 
Author Message
PostPosted: Thu Jan 22, 2004 11:12 am 
Offline

Joined: Thu Jan 22, 2004 10:24 am
Posts: 17
I posted this some time ago at the Lemon forum, but I figured it would not be out of place here:

I transfered some of my mathematical BASIC programs from floppy to the PC to use in emulators, but I noticed that some don't work as they should with CCS64.

I isolated a line that CCS64 did not like. Let's say that the { symbol represents the symbol you get if you type SHIFT with the move-cursor-right key on the C64 within quotes (which should give the effect of moving one space to the left with the INPUT and PRINT commands). For some reason, if I have a line such as INPUT"!{{";N in a program, when any number is entered for the input, the message ?REDO FROM START appears. The program is stuck like this -- any attempt to enter a number gives that message.

VICE has no such problem. Is this a bug with CCS64 or what?

By the way, the reason I have such an input line is to put the ! symbol at the left of the screen and have the user enter a number that appears right next to the ! symbol. I read there's a way to get rid of the ? that shows with INPUT lines, so I know I could just program it differently, but what I am curious about here is why CCS64 handles my INPUT line differently than my real C64 and VICE.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Jan 23, 2004 9:18 am 
Offline
Site Co-Admin

Joined: Wed Aug 20, 2003 2:46 pm
Posts: 786
Location: East Yorkshire, England
Try another version of BASIC.ROM first. I'll keep an eye on this.

_________________
Kind regards,

Stuart Toomer.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Jan 23, 2004 9:52 pm 
Offline

Joined: Thu Jan 22, 2004 10:24 am
Posts: 17
OK, I tried VICE's basic file, renamed it basic.rom and put it into CCS64's folder. The effect is still there.

Next I replaced the kernal.rom file with VICE's. That fixed it -- the effect disappeared.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Jan 24, 2004 2:01 am 
Offline

Joined: Sat Jan 03, 2004 11:42 pm
Posts: 12
nicknicknickandnick wrote:
Next I replaced the kernal.rom file with VICE's. That fixed it -- the effect disappeared.

Another rev.2 kernal bug, then. Vice uses a rev.3 and many games/demos in CCS work correctly only with this.
What happens in vice if you put the CCS kernal? same bug?

_________________
-=[]=--- iAN CooG ---=[]=-


Top
 Profile  
 
 Post subject:
PostPosted: Sat Jan 24, 2004 11:43 am 
Offline

Joined: Thu Jan 22, 2004 10:24 am
Posts: 17
Yes -- I tried VICE with the CCS kernal, and that caused VICE to show the effect too.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Jan 24, 2004 11:55 pm 
Offline

Joined: Mon Sep 15, 2003 7:14 am
Posts: 66
This sounds to me like a line-linking problem related to cursoring off the left side of the screen. That would be a C64 Kernal bug rather than an emulation bug. Obviously, switching to a newer ROM revision fixes it.

However, if there's any chance that you may distribute your program, you will probably want more compatibility. One possible workaround would be to put a space before the exclamation point, which would cause the prompt to look like "?!". The question mark can easily be hidden, though, with some fiddling with the horizontal scrolling register. However, other print statements would need to be changed, too, since the leftmost column of the screen is hidden. I'm not even sure that this will get around the problem!

More practical, although more complex, is to have a subroutine that uses GET to handle input. This is what I'd recommend, as it gives you full control over the prompt, what input to handle, and even the cursor if you really want to impress people.

I should probably get a copy of all the different ROM revisions so I can test them with the game I'm working on. It sounds to me like CCS64 has R2, Vice comes with R3... Do I hear R1 anywhere?

_________________
Image


Top
 Profile  
 
 Post subject:
PostPosted: Mon Jan 26, 2004 12:04 am 
Offline

Joined: Thu Jan 22, 2004 10:24 am
Posts: 17
Thanks for the answers. I found a really simple thing I could do to be rid of the question mark with an INPUT statement: POKE 19,1 then the INPUT statement, then POKE 19,0 to restore the default.


Top
 Profile  
 
 Post subject:
PostPosted: Tue Jan 27, 2004 4:01 pm 
Offline
Site Co-Admin

Joined: Wed Aug 20, 2003 2:46 pm
Posts: 786
Location: East Yorkshire, England
Yes, CCS64 comes with Revision 2 of the ROMs, and as we know, some bugs are fixed in the Revision 3 ROMs; so it's preferable to use the more up-to-date revisions.

Some versions of the 1541 ROM also fix/introduce other bugs, but that's more of a nightmare...

_________________
Kind regards,

Stuart Toomer.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC + 2 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group