Video Test Pattern on LCD!

A project log for ISA 8-Bit Video Experiments

A Series of Experiment to Create an ISA 8-Bit Video Card

Dave's Dev LabDave's Dev Lab 08/20/2019 at 03:020 Comments

After doing a bit of debugging, I was happy to see data on the LCD panel! The test pattern data is just a cycle through the 0 to 255 ASCII characters. the LCD display is a 480x272 pixel display. using the 8x8 character from the CGA/MDA ROM, give me a character resolution of 60x34. Couple of minor issues interfacing to the LCD. The LCD is expecting negative triggered VSYNC and HSYNC, but the MC6845 is outputting positive edge VSYNC and HSYNC. i had to cobble on some inverters. The datasheet for the LCD indicates that it can work without Data Enable (DE), but i wasn't able to get that working, so I needed to connect the DE from the MC6845 to finally get it working! on to the next phase!