Commodore 128 Alive!

Commodore 128 => 128 programmers => VDC Programming => Topic started by: Blacklord on June 12, 2006, 10:21 AM

Title: 40 colum display on an 80 colum screen
Post by: Blacklord on June 12, 2006, 10:21 AM
Note - first time program is run, it switches the VDC to 40 column mode, if run a 2nd time it switches VDC back to 80 columns

10 READX$,O$:L=LEN(O$)-1
20 FOR J=1toL STEP2
30 O=DEC(MID$(O$,J,2)):X=DEC(MID$(X$,J,2))
40 SYS 52689,,X:RREG A
50 A=XOR(A,O):SYS52684,A,X
60 NEXTJ
70 DATA"00010216191B)","417853F11028)"
Title: 40 colum display on an 80 colum screen
Post by: OzOne on June 13, 2006, 04:41 AM
Quote from: adminNote - first time program is run, it switches the VDC to 40 column mode, if run a 2nd time it switches VDC back to 80 columns

10 READX$,O$:L=LEN(O$)-1
20 FOR J=1toL STEP2
30 O=DEC(MID$(O$,J,2)):X=DEC(MID$(X$,J,2))
40 SYS 52689,,X:RREG A
50 A=XOR(A,O):SYS52684,A,X
60 NEXTJ
70 DATA"00010216191B)","417853F11028)"
But don't try this in Vice! Works fine on my real 128, but the screen screws up big time in Vice (Windows version anyway) and won't restore without a reset.

Ozzy
Title: 40 colum display on an 80 colum screen
Post by: xlar54 on June 13, 2006, 01:30 PM
Maybe we should toss this over to the vice team so they can work on improving the emulation.  Does anyone know if VICE will handle 50 rows?  Desterm will swtich to 50 rows on the 80 column screen.

Wonder what ever happened to Desmond.  The guy was a good programmer.
Title: Re: 40 colum display on an 80 colum screen
Post by: airship on September 10, 2008, 06:02 AM
Over two years later, this is still broken in VICE.
Title: Re: 40 colum display on an 80 colum screen
Post by: Andrew Wiskow on September 11, 2008, 10:19 AM
Quote from: airship on September 10, 2008, 06:02 AM
Over two years later, this is still broken in VICE.

Has there been an update to VICE128 in the past two years?
Title: Re: 40 colum display on an 80 colum screen
Post by: hydrophilic on September 11, 2008, 03:31 PM
Besides 2MHz support (about 2 years ago now!), there have been a few tweeks in the VDC.  The underline and flash attributes now work for example.   If I had the time, I'd work on variable screen size and interlacing...
Title: Re: 40 colum display on an 80 colum screen
Post by: xlar54 on September 30, 2008, 03:30 PM
Without sounding presumptious that he would help them, it would be nice if these folks would talk with BDD regarding any remaining VDC issues.  I think we all can agree on his knowledge of the subject.  And VICE would be all the better for it.
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