Commodore 64 glitch

fun with poke 53272,x

Category:

Film & Animation

Tags:

• Commodore
• 64
• glitch

[mar777i]

@phodd according to fairlight's vic documentation, it's a RES bit which resets the 6566 version of the vic-2. however, the way I read the document it did not have any effect on the 6567/6569 which the document is focused at. myself I own a pal 128d and an old breadbox which both did not break on beneath code. I'm sceptical against these "killerpoke of death" roumors.

[phodd]

@mar777i That program's technically dangerous; It can set bit 5 of 53270 and the chip documentation says not to do that. (Although it's not made clear why).

[mar777i]

you can have all the fun at once:

10forx=0to255

20a=int(rnd(0)*3):ifa=0thenpok­e53272,x:goto50

30ifa=1thenpoke53270,x:goto50

40ifa=2thenpoke53265,x:goto50

50next

60goto10

[tsuihark]

THe C64 is easy to glitch, it will often start glitching by itself without warning ;)

[forumlalampara]

@AssemblerGuy : Thank you very much for these informations my friend !!!!! I send a private message to you because I have to ask you another thing... I hope that you will answer to it !!!! Hugs and thank you once again !!!!! :-)

[AssemblerGuy]

@forumlalampara If it happens when starting the machine, it's a sign that the machine is malfunctioning. If it happens when running a program, it's almoat always because there has been some flaw in the program.

In this video though, vjslof is just POKE-ing values into a register that causes the graphics chip to show funny bars and stripes -- nothing broke in this case.

[forumlalampara]

@AssemblerGuy :dear friend, excuse me for the disturb and for my bad English, but I would like to ask a question to you: In this video I saw some reverse bars that appear and fill the screen... Before having the Commodore 64, I had a Commodore Plus 4, and I remember that these bars used to appear also on this computer, and sometimes appeared randomly, even blocking the machine... Do you know what these bars are and why they appeared ??? Thank you in advance and have a merry Christmas !!!!!

[AssemblerGuy]

53272 (or $D018 in hexadecimal) is a register that tells the system two things: Where in memory to get the character set, and where to get the text content to be displayed on the screen, using that character set.

Other fun addresses to poke around with are:

53270 ($D016 in hex.): Horizontal pixel scrolling and multicolor/hi-res mode selection

53265 ($D011 in hex.): Vertical pixel scrolling, selection of bitmap mode and "extended color mode"

[xOnyxTheHedgehogx]

THAT'S AWESOME.

[noxgenus]

sweet