jazzed challenged me to make a full color video driver for output to television using the Propeller Platform (by: Gadget Gangster) SDRAM module for the frame buffer and video output. Giving the conditions that it must exceed the current drivers in display capability, to the point of being able to not having to repeat any pattern in order to fill the display and it must use 5 COGS or less.
And I accepted his challenge. I am going to order the SDRAM module as soon as I can afford it. In the mean time I will be using a SDRAM IC scavenged from an old DIMM to get started (to which I had already soldered leads to breadboard it for another project, that is long since done). I am also looking through all my old hardware to find the appropriate resistors for the video out. Hopefully the IC on the SDRAM module is close enough that I will not have to make major modifications in order to use my code on the correct HW.
So as to keep the number of posts I have decided to post a periodic log of the status of the progress I am making with this project. and here it is:
1:) Pixel and simple line drawing functions implemented. Up to 2000 vector draw commands per
frame, though in some cases as few as 150 (figure aprox 2000 pixels updated by vector drawing
2:) Still trying to get the output timing lined up for NTSC video. This part may take a while.
Wow what a day. I have not accomplished this much in a single day in a while.
Today I accomplished the fallowing:
1:) Accepted the challenge to code a better TV video driver for the Propeller Platform using
2:) Managed to get a SDRAM driver working on the Propeller, that is based on an earlier,
unreleased driver that I had written for the AVR.
3:) Got the SDRAM read and write speed up to about 4700000 bytes per second max. This
is fast enough for this application.
4:) Began refreshing my knowledge of NTSC, and began studying PAL in relation to NTSC.
Hoping for the Prop II. I like ARM, though need a Prop II to complement it.