vga progect to replaced outdated equipment(cirus locigc chip and 386 micro cont

mike goettling

I am doing an evaluation of the propeller chip for our company. This will be a product that takes serial data and converts to a vga text output 80 char by 24-30char. We currently use a unit designed about 10 years ago using a 386 microcontroller and a cirrus logic vga chip. This would be a perfect replacement for this board. If it works I would guess we would use 400 to 600 chip per year. If I get it to also work with tv also that would be even more per year. With that said here is my problem. I am limited on time. I have got it to work with are system using High-Res Text Driver v1.0 works great except for color. I have to be able to change the color of each character not per line. The vga driver will do this but I can’t get it to 80 characters. First how far can you push the vga driver for resolution. Would it handle 1024/768?·· Second can it point to a different character set of smaller tile size?
I am having problems figuring it out due to lack of knowledge. I am just needing a good push in the right direction or some contracting assistance. with that said any help is appreciated. it has been over 15 years since i programed assymbly with the motrola hc811.

Mike Green

Chip had experimented with a series of VGA drivers that provided tiled graphics (and text) in varying resolutions using a 16 x 16 pixel tile. There was one that I use now that did 64 columns x 24 rows and 1024 x 768 pixel resolution. Each tile can have one of 64 sets of 4 colors. For text you have foreground and background only, but any one of 64 combinations of foreground and background.

The 1280 x 1024 pixel resolution driver will provide 80 x 32 text. It requires 4 cogs, but that leaves plenty for a full duplex serial driver and a control routine (6 out of 8 cogs). The link is http://forums.parallax.com/showthread.php?p=617144.

The 1024 x 768 driver is here http://forums.parallax.com/showthread.php?p=614615.

You could actually provide simultaneous VGA and TV outputs with the TV limited to 40 x 13 (due to basic limitations in NTSC video). The FullDuplexSerial driver is included with the Propeller Tool. With these two drivers, all your coding could be in Spin.

Mike Green

The main reason for a 16 x 16 tile is that there's a really nice 16 x 32 or 16 x 16 font in ROM in the Propeller. You could certainly use an 8 x 16 font if you supplied it yourself. The main reason for the multiples of 8 is that it fits better with the video hardware in the Propeller.

You could probably prototype something in a few hours given the VGA, TV, and serial drivers.

mike goettling

i will try the 1280*1024 driver. that may do what i need.