Log inRegister an accountBrowse CSDbHelp & documentationFacts & StatisticsThe forumsAvailable RSS-feeds on CSDbSupport CSDb Commodore 64 Scene Database
 Welcome to our latest new user Vaz ! (Registered 2018-02-19) You are not logged in 
CSDb User Forums


Forums > C64 Coding > Screen on or screen off... this is the question!
2018-01-14 14:56
Flavioweb

Registered: Nov 2011
Posts: 347
Screen on or screen off... this is the question!

I have this code
.C:c000  78          SEI
.C:c001  A9 80       LDA #$80
.C:c003  CD 12 D0    CMP $D012
.C:c006  D0 FB       BNE $C003
.C:c008  A9 00       LDA #$00
.C:c00a  8D 11 D0    STA $D011
.C:c00d  2C 11 D0    BIT $D011
.C:c010  10 FB       BPL $C00D
.C:c012  A9 80       LDA #$80
.C:c014  CD 12 D0    CMP $D012
.C:c017  D0 FB       BNE $C014
.C:c019  A9 1B       LDA #$1B
.C:c01b  8D 11 D0    STA $D011
.C:c01e  60          RTS

Using Vice, if i set a break point at $C019, i would expect to have the screen turned off here... but is not so.
I have only a black "fld" line in the middle of the screen

Is it a correct behavior?
2018-01-14 18:27
Fresh

Registered: Jan 2005
Posts: 82
Here it's working fine in both X64 and X64SC (Version 3.1).
If you're using VICE on Windows you may have to trigger a redraw (ie cover the emulator window with another app and then remove it).
Don't know if this apply to other OSes.
2018-01-14 19:46
Flavioweb

Registered: Nov 2011
Posts: 347
I'm using x64sc 3.1 r34148 (GTK+) compiled from sources on openSUSE Tumbleweed...

Better double check my codes on RH.
2018-01-15 18:41
Han

Registered: Apr 2017
Posts: 8
Are you trying to disable the screen only partially? Unfortunately that's not possible.
2018-01-15 19:01
JackAsser

Registered: Jun 2002
Posts: 1270
Quote: Are you trying to disable the screen only partially? Unfortunately that's not possible.

It most definetly is by doing a reverse side border opening. But it requires cycle precise timing per raster line closed, i.e. totally useless.
2018-01-15 21:07
Flavioweb

Registered: Nov 2011
Posts: 347
Quote: Are you trying to disable the screen only partially? Unfortunately that's not possible.

No... I'm just testing when the video is turned off.
Since, as written in Vic Article, DEN bit is checked somewhere in raster line $30, i'm expecting that clearing it at line $80 and then wait for line $80 again, in next frame, screen should be off.
But i can't see this in Vice.
In the "next frame" i can just see some DMA artifacts... but screen still ON (since, at least, at the end of second frame).
So i'm thinking if this "frame" is part of the normal behavior of the VIC or it happen just in (my) Vice.
2018-01-15 21:52
Han

Registered: Apr 2017
Posts: 8
Oh, now I see what you are doing. And Fresh is right: you have to force a redraw. When I grab the emulator window and move it, the upper half of the screen is suddenly disabled.
RefreshSubscribe to this thread:

You need to be logged in to post in the forum.

Search the forum:
Search   for   in  
All times are CET.
Search CSDb
Advanced
Users Online
Acidchild/Padua
Dymo/G★P
Sith
Nutfreak/Freedom Sys..
Zardax/Artline Designs
Marvin/DPS
algorithm
Guests online: 51
Top Demos
1 Uncensored  (9.7)
2 Edge of Disgrace  (9.7)
3 Coma Light 13  (9.6)
4 The Shores of Reflec..  (9.6)
5 Comaland 100%  (9.6)
6 Lunatico  (9.6)
7 Incoherent Nightmare  (9.5)
8 Wonderland XII  (9.5)
9 Comaland  (9.5)
10 Wonderland XIII  (9.5)
Top onefile Demos
1 Pandemoniac Part 2 o..  (9.5)
2 Daah, Those Acid Pil..  (9.5)
3 Dawnfall V1.1  (9.5)
4 Synthesis  (9.5)
5 Treu Love [reu]  (9.5)
6 Merry Xmas 2017  (9.5)
7 FMX Music Demo  (9.4)
8 Dawnfall  (9.4)
9 Tribute to Bob Wakelin  (9.3)
10 Hardware Accelerated..  (9.3)
Top Groups
1 Oxyron  (9.4)
2 Booze Design  (9.4)
3 Censor Design  (9.3)
4 Crest  (9.3)
5 Finnish Gold  (9.3)
Top Mega Swappers
1 Aslive  (9.3)
2 R.C.S.  (9.3)
3 Dishy  (9.2)
4 Calypso  (9.2)
5 Nightshade  (9.1)

Home - Disclaimer
Copyright © No Name 2001-2018
Page generated in: 0.304 sec.