VGA with 3 Pins ***UPDATE*** VGA with 5 Pins and 8 Fore/Background-Colors

zx81vgazx81vga Posts: 26
Hello Propeller-Friends,

sometimes i need more Pins on the Propeller with VGA.

The Result is:

VGA3PIN 1.0

here to find

http://propeller.ws-nbg.de/main.php

Greetings from Nuremberg, Germany

Werner

Comments

  • 7 Comments sorted by Date Added Votes
  • Thanks Werner, I will try it out. Like the LCARS website, had to think for a moment to find the code. :)
  • roglohrogloh Posts: 503
    edited February 2016 Vote Up0Vote Down
    Hello Werner,
    If you want to save another pin, I have found some monitors will allow a composite sync signal to be used instead of separate H/V syncs (I have a couple of Sony Trinitrons that do this). Depending on your monitor support you can also resistively add the signals to combine sync and green video together resulting in a 2 wire VGA cable. Here is a snippet of a circuit I successfully used with the P1 when I was pin limited to get simultaneous composite and VGA signals generated. I was using a 1 pin composite object available from the OBEX if I recall correctly and my own two pin VGA using Sync on Green. So just 3 pins gave me my mono VGA and composite video leaving a lot of pins freed which I needed for my other buses [img][/img]

    vga.png
  • rogloh wrote: »
    Hello Werner,
    If you want to save another pin, I have found some monitors will allow a composite sync signal to be used instead of separate H/V syncs (I have a couple of Sony Trinitrons that do this).

    In another forum, the claim was that pretty much all VGA Monitors simply XOR H & V, then extract sync info.
    Could pay to test that ?

  • Hi Propeller-Friends,

    there is an Update

    Changes in v1.1

    VGA 256x192 BMP
    VGA 320x240 BMP
    VGA 512x384 BMP

    added. :smile:

    Greetings from Nuremberg, Germany

    Werner
  • tonyp12tonyp12 Posts: 1,745
    edited February 2016 Vote Up0Vote Down
    Should not be to hard to create composity sync in software, but does 90% of monitors support it and should you use H-sync input for it?
    Sync compositing in the computer industry.
    As these signals are normally generated by digital logic circuits in computer systems, the composite sync signal has also commonly been produced simply by OR-ing (a)
    or exclusing-OR-ing (b) the horizontal and vertical sync signals.

    The former practice is commonly known as “block sync,” and no horizontal pulses occur during the composited vertical sync pulse.
    The XOR compositing produces serrations similar to those produced in television practice, but without preserving the falling edge position.

    Note also that, since the vertical sync in typically produced by counting horizontal sync pulses, the V. sync leading and trailing edges usually occur slightly after the H. sync leading edge; this can result in the spurious transitions shown in the composite sync output if the two are simply XORed, as in (b).

    tmp7ee1141_thumb.png
  • zx81vgazx81vga Posts: 26
    edited February 8 Vote Up1Vote Down
    Hi Propeller-Friends,

    there is a new Update for VGA3PIN :smile:

    Changes in v1.2

    vga3pin_modes.png

    Greetings from Nuremberg, Germany

    Werner
  • zx81vgazx81vga Posts: 26
    edited February 10 Vote Up1Vote Down
    Hello Propeller-Friends,

    Here is a 5 PIN Version:

    VGA5PIN 1.1 with 8 Fore/Background-Colors

    here to find

    propeller.ws-nbg.de/main.php

    vga5pin_modes.png

    Have Fun...

    Greetings from Nuremberg, Germany

    Werner
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