Dragon's Lair Fans - Arcade Lifestyle

General Chat => Technical Area => Topic started by: retrocab on July 08, 2015, 08:14:47 PM

Title: roadblasters graphic issue
Post by: retrocab on July 08, 2015, 08:14:47 PM

]hi there

my roadblasters has an issue ,vertical stripes on the screen
ram rom test oke
game plays and has sound
any help is welcome
gr robert

(http://i881.photobucket.com/albums/ac17/arcade02/DSC09795_zpsuxfq1wyf.jpg)][URL=http://s881.photobucket.com/user/arcade02/media/DSC09795_zpsuxfq1wyf.jpg.html](http://i881.photobucket.com/albums/ac17/arcade02/DSC09795_zpsuxfq1wyf.jpg) (http://[URL=http://s881.photobucket.com/user/arcade02/media/DSC09795_zpsuxfq1wyf.jpg.html)[/url]

Title: Re: roadblasters graphic issue
Post by: ajhippel on July 08, 2015, 09:28:53 PM

try:
remove, clean the legs and insert back again the graphic eproms

Title: Re: roadblasters graphic issue
Post by: Etienne MacGyver on July 09, 2015, 12:04:56 AM

Are thos not retrace lines ?

I could be wrong ofcourse, but its worth a shot to turn the screen pot on the flyback a bit down.

Title: Re: roadblasters graphic issue
Post by: level42 on July 09, 2015, 12:12:10 AM

Nope.

Road Blasters is a horizontal game and retrace lines would show up horizontally.....not vertically like this.



For example:
(http://petes-emulation.com/ftp/acm/pics/tube_swap4_results_hmmm.JPG)

Title: Re: roadblasters graphic issue
Post by: anunaki on July 09, 2015, 11:46:41 AM

huh? I thought the working of a monitor is not based on the orientation of the game played on it?

Isn't it always drawing the lines bases on a vertical perspective?

Title: Re: roadblasters graphic issue
Post by: level42 on July 09, 2015, 12:19:59 PM

Indeed the working of a raster monitor/CRT TV is always the same: it draws lines horizontally line by line. When it reaches the end of a line the beam is "steered back" to the beginning position while the gun is turned "off" but it can't be turned off completely and when the brightness is too high you can actually see the retrace lines.

https://www.youtube.com/watch?v=dlT-seESkj0


Horizontal on a CRT always means the orientation with the widest distance, vertical the shortest, so....like it would be positioned in a normal TV.

If you turn the monitor or TV on it's side, it still keeps scanning the same way, that doesn't change of course :)

So...a vertical position monitor could show retrace lines vertically, but Road Blasters is a horizontal game and thus retrace lines would look (mostly) horizontal.

Title: Re: roadblasters graphic issue
Post by: anunaki on July 09, 2015, 12:43:13 PM

thx :)

Title: Re: roadblasters graphic issue
Post by: mikemcbike on July 09, 2015, 01:47:27 PM

IMHO it seems not to be only a sprite GFX EPROM issue, because the stripes are also visible on background graphics (road surface for example).

Title: Re: roadblasters graphic issue
Post by: retrocab on July 09, 2015, 07:43:40 PM

thnx for the tips
 but sadly nothing further ,stiil that weird stripes

Title: Re: roadblasters graphic issue
Post by: level42 on July 09, 2015, 09:12:45 PM

If you have a way to verify the graphics ROMs then do that. Use this website to confirm if they match:

http://romident.coinopflorida.com