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80-column text on TV? — Parallax Forums

80-column text on TV?

RaymanRayman Posts: 14,237
edited 2008-08-12 22:38 in Propeller 1
I'm thinking that it should be fairly straightforward to do a 80-column display of 8x16 or 8x12 font (maybe Clemens' secret font?) for the TV...

But, would 80 columns of text even be legible on a TV?

(On the other hand, it seems that most new TVs have VGA input and we already have a hi-res VGA text driver, so maybe it's not worth the trouble anyway.)

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-08-05 23:31
    Rayman said...
    But, would 80 columns of text even be legible on a TV?
    Probably not. My first two computers (Poly 88 and TRS80) both had 64 characters per line, and even they required a black-and-white baseband monitor for the video to be legible. Early color computers with TV outputs were limited to 40 characters per line, due to bandwidth limitations.

    -Phil

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  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2008-08-05 23:34
    I'd have to agree... The 80 column cart I had for my C64 was terrible.
    You could read it, but you didn't enjoy it.

    Perhaps a happy medium could be found? Say 60x32? A bit oddball but
    would be very useful for things like my text editor.

    OBC

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  • Mike GreenMike Green Posts: 23,101
    edited 2008-08-05 23:58
    The 40 columns that the existing text driver provides is small enough and fuzzy enough for me. I've tried 64 characters on a line and the quality and readability is terrible. 80 columns does show up, but it's even worse. If you disable the color, it's better.
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2008-08-06 00:28
    heh.. got the hint Mike.. [noparse]:)[/noparse]

    If I could find a reasonable way to do portable VGA I'd probably switch myself.

    OBC

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  • potatoheadpotatohead Posts: 10,261
    edited 2008-08-09 21:48
    One of the drivers I posted will do 64 chars easily enough.

    http://forums.parallax.com/forums/default.aspx?f=25&m=220192

    It's legible on most newer TV's. You will note the really clear screen capture I did in the first post of that thread. That was done by feeding the baseband video into the luma input of an s-video capable capture card. The same trick works on TV's, if they have an s-video input option. Do that and it's clean and clear. A simple cable hack is all that is needed for that to work.

    The next clear option, given a TV with RF, or composite only input, is to cut the color saturation down to a low or zero value. This driver uses a fixed color clock, or non-interlaced color. The upside is that artifacts are stable and can be incorporated into graphics. The downside is more limited color resolution. (160 pixels in the safe area) If you do use color, your best option is to make the text the same color, or very nearly the same color and moderate differences between the luma value of the background and the text. ie: brighter blue on dark blue, or white on dark blue.

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  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2008-08-10 21:30
    Doug,

    You got me wondering just how far I could push your color text driver.
    Char08 will go 52x25 reasonably before it seems to turn into mush.. [noparse]:)[/noparse]
    Still nicely viewable on my 7" screen, but not something I'd want to stare
    at all day..

    OBC

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  • potatoheadpotatohead Posts: 10,261
    edited 2008-08-12 04:30
    Best to go monochrome (B & W), or single color (color + luma for text), if anything higher is desired. Single color probably breaks down before 64 chars. Never really tried it.

    Did you try your small display in monochrome only? Set all the color bits to just grey scale value and give it a go.

    I don't have a small LCD to test. On my capture card the 64 is just clear. On my small CRT, in monochrome, it's serviceable and that's about it. The larger CRT television reproduces it clean and clear, no problem.

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  • VIRANDVIRAND Posts: 656
    edited 2008-08-12 05:02
    This was on my short list of things to try but I haven't done it yet. Actually I'm close but not done.
    I have the TV driver going fast enough for 82x25 columns of 5x7 text but I didn't put the font in yet.

    80 columns IS (sometimes) readable with composite video.
    Apple II had an optional 80 column composite video card that was used with professional software
    such as wordprocessors and spreadsheets and stuff, and I saw it used a lot without complaints.
    edit:as I recall IBM also did it with GWBASIC "SCREEN 2", and I used it a lot with a CGA card with composite video output.

    Post Edited (VIRAND) : 8/12/2008 5:08:19 AM GMT
  • VIRANDVIRAND Posts: 656
    edited 2008-08-12 22:38
    80 column text on a TV does usefully work, as long as it's not a crappy TV. Works fine on 2 TV's I tried.
    I'll upload my demo later.

    Here it is. It hogs up all the hub RAM for a 512x192 4-color bitmap, so it's really only useful for testing the quality of TV's.
    Similar to the 80 column APPLE II font, except that lowercase is just smaller capital letters,
    and the only other characters are numbers. Just type a lot of stuff on the screen.
    It uses TV Graphics and comboKeyboard drivers, they're not included, but they should be in your Propeller Tool.

    Post Edited (VIRAND) : 8/13/2008 6:37:25 AM GMT
    spin
    spin
    an80columndemo.spin
    18K
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