
Announcement/Download
MAXIMUM OVERSCAN
A further extension of the UBERMODE-graphics-mode from 2013 now providing a resolution of 224x283 pixels on a PAL VIC-20 with added raster-splits for more color-choices per picture:
- 224x283 hires or 112x283 multicolor pixels (true resolution)
- 8x8 blocks for foreground color (4x8 for multicolor)
- background/border color split every 8 rasterlines (36 total)
- auxiliary color split every 32 lines (9 total)
- 24K RAM expansion required
Short reference:
GRAPHIC ON: SYS 9774 (SPACE to return to BASIC prompt)
See pgm-import on how to set single pixels, clear the screen and on how to set the color-RAM and backgroud/border/auxiliary colors.
Technical background of the graphics-mode:
Back in 2015, a short time after creating some different modes for the VIC-20 I realized I was lying about 224x280 being the maximum possible resolution on the PAL VIC-20. In fact 3 more lines are possible and visible in VICE as well as monitors that can adjust the viewable area as much as possible, such as the Commodore 1084. With this monitor I checked that in fact 224x283 would be the maximum resolution fully visible. I tried expanding it to 232 horizontal width. but this would lead to some pixel being no longer inside the visible area.
As soon as I had the 224x283-mode working I still had some raster-time left which I used for raster-splits of the remaining global colors as much as possible.
This mode leaves just 2 cycles of CPU-time per raster unused - a single NOP-operation.
As usual a picture converter for converting monochrome 224x283 pixel .pgm-files is included in this package as well. This relatively short program also shows how to set pixels and colors. Simply convert any picture with a 4:3 aspect ratio without ratio correction to 224x283 on your PC and then have the PGM-converter run through it. This will create an executable files which can be RUNed or started by SYS 9774.
With this mode the PAL VIC-20 can now display 63392 pixels, just 608 short of the C64 in hires-mode!
History:
This mode lay dormant for some years, since I discussed with Mike from time to time to do a picture-converter for it. He (rightfully) noticed that the extra horizontal splits every 8 or 32 lines would usually not improve the picture quality very much and would not justify the programming-effort needed to take care of this (a simple case of diminishing returns). So I just went ahead with my usual .pgm-converter and hand-poked some colors into the Nordlicht-logo. The final picture (seen above) is just the result of a small BASIC-program that sets the pixels and colors in such a way you can see the colorfullness of this mode in its full glory

I finally decided to release it in this years Gravedigger-competition at the Nordlicht-demoparty where it got the 7th place out of 13 in that compo.