Shop OBEX P1 Docs P2 Docs Learn Events
Simple NTSC Text Driver — Parallax Forums

Simple NTSC Text Driver

ozpropdevozpropdev Posts: 2,792
edited 2015-11-11 04:47 in Propeller 2
Update: Now supports 8x16,16x16 and 16x32 size fonts.
See here
Hi All
Here's a quick and dirty NTSC text driver based on Chip's NTSC demo.
It produces 12 lines of 16 characters and uses just 1 cog.
Ascii data in hub space is converted to pixel data during the 192 line field loop.
The demo shows 10 cogs modifying hub ram simultaneously.
I found it useful as I am using all the leds on the A7/DE2 boards and serial so being able to get additional debug data was handy.
I cheated and use the color pallete from Chip's bitmap :)
p2_ntsc_text.jpg
592 x 1056 - 259K
spin
spin
qd_ntsc_text.spin
80K

Comments

  • BaggersBaggers Posts: 3,019
    Nice one ozpropdev :D
  • potatoheadpotatohead Posts: 10,261
    Nice!

    Having text to gawk at sure helps!
  • 78rpm78rpm Posts: 264
    I like that!

    What size monitor/tv, looks around 10" - 12" comparing screen size to connector size?

    I will have to look for the appropriate connectors and a cable, which are safely stored ... somewhere ... to use the other cog in by bare-board Nano setup.
  • ozpropdevozpropdev Posts: 2,792
    @78rpm
    Yep a 12 inch monitor.
    Sadly the NTSC driver doesn't fit the nano. The frame buffer is 49.1k and then theres the font data on top of that.
    :(
  • 78rpm78rpm Posts: 264
    @ozpropdev

    Shame. Bigger fpga needed obviously, unless it is possible to have the frame buffer ASCII chars only and convert on the fly, in a similar manner to the hi-res VGA on P1?
  • TubularTubular Posts: 4,654
    That's looking mighty useful!
  • msrobotsmsrobots Posts: 3,709
    I am already stumbling at the first lines of code:
                    rep     @cogz,#10       'launch 10 cogs
                coginit #16,##@testcode
cogz

    doesn't that start the same cog 10 times?

    confused!

    Mike
  • mindrobotsmindrobots Posts: 6,506
    edited 2015-11-11 02:18
    #16 tells cognitive to start the next available cog

    Cognitive. ... thanks, autocorrect!! :)
  • msrobotsmsrobots Posts: 3,709
    mindrobots wrote: »
    #16 tells cognitive to start the next available cog

    ahh - I missed that one...

    Thanks,

    Mike

  • ozpropdevozpropdev Posts: 2,792
    I made a few tweaks to the driver and it now supports 8x16,16x16 and 16x32 font sizes.

    8x16 font.jpg
    2285 x 1713 - 1M
    spin
    spin
    qd_ntsc_text_v3.spin
    81K
  • cgraceycgracey Posts: 14,133
    edited 2015-11-11 04:32
    Having a video display is great for testing. I've been limited to a 16 channel logic analyzer, so far.
  • jmgjmg Posts: 15,159
    cgracey wrote: »
    Having a video display is great for testing. I've been limited to a 16 channel logic analyzer, so far.
    You could claim that adding this actually shortened the critical path, due to higher testing productivity ;)

  • 78rpm78rpm Posts: 264
    jmg wrote: »
    cgracey wrote: »
    Having a video display is great for testing. I've been limited to a 16 channel logic analyzer, so far.
    You could claim that adding this actually shortened the critical path, due to higher testing productivity ;)
    That's one reason I started to put together the software test harness I've been using. It makes it so much easier to see inside.
  • cgraceycgracey Posts: 14,133
    I got the streamer docs done! They could stand some improvement, but I think I got all the details in there.
  • potatoheadpotatohead Posts: 10,261
    Looks great Chip.

    I'm doing simple 2 color right now. Was nice to have the mode bits. :)

  • cgraceycgracey Posts: 14,133
    potatohead wrote: »
    Looks great Chip.

    I'm doing simple 2 color right now. Was nice to have the mode bits. :)

    Great! It would be good if people wound up trying all the modes.

    I'll work on the colorspace converter documentation tomorrow.
  • potatoheadpotatohead Posts: 10,261
    Well, the 1, 2, and 4 bits all do what they say.
Sign In or Register to comment.