BitFracture
New Member
- Joined
- Dec 31, 2014
- Messages
- 4
Hello,
I recently acquired a second VIC-20 machine that wouldn't power on due to the 5V half of the power switch not working. Once I fixed this, my graphics were colourful and garbled (compared below with my working VIC-20.)
I read into this document a bit:
http://www.classiccmp.org/dunfield/vic20/v20diag.txt
It seems that it may be caused by UB9 (M53202P), "Partial failure can produce missing color or incorrect colors, slight or severe tearing of picture or diagonal lines" or UC2 (74LS138), "Screen character colors incorrect (scrambled)."
My question for y'all: have any of you experienced similar problems before? If so, how did you go about fixing them? I am hoping to gain some insight from others before I start buying chips, especially since neither of the descriptions above fits my exact problem very well.
Thanks
I recently acquired a second VIC-20 machine that wouldn't power on due to the 5V half of the power switch not working. Once I fixed this, my graphics were colourful and garbled (compared below with my working VIC-20.)
I read into this document a bit:
http://www.classiccmp.org/dunfield/vic20/v20diag.txt
It seems that it may be caused by UB9 (M53202P), "Partial failure can produce missing color or incorrect colors, slight or severe tearing of picture or diagonal lines" or UC2 (74LS138), "Screen character colors incorrect (scrambled)."
My question for y'all: have any of you experienced similar problems before? If so, how did you go about fixing them? I am hoping to gain some insight from others before I start buying chips, especially since neither of the descriptions above fits my exact problem very well.
Thanks