VGA HiRes Text

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By: Chip Gracey (Parallax), created: 2013-04-17 | updated: 2013-04-17

This object generates a 1024x768 VGA signal which contains 128 columns x 64 rows of 8x12 characters. Each row can have a unique forground/background color combination and each character can be inversed. There are also two cursors which can be independently controlled (ie. mouse and keyboard). A sync indicator signals each time the screen is refreshed (you may ignore).

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Package icon VGA_HiRes_Text_Demo_-_Archive__Date_2008.02.27__Time_15.06.zip21.81 KB

Comments

[originally posted by Anonymous on 2010-12-30 05:04:31] Wow! This is really useful.

Hello Chip,

I'm using your "VGA_HiRes_Text" in my application, which is a simple serial data-to-display converter.

I modified the font array to match the characters I need, and use the original 640x480 resolution for displaying 80 x 40 characters.

I would like to be able to display 24 x 12 characters (192 X 144 pixels), but I have no idea how to calculate/modify the VGA parameters to achieve this, if possible at all.

Can you assist?

  hp = 640      'horizontal pixels
  vp = 480      'vertical pixels
  hf = 24       'horizontal front porch pixels
  hs = 40       'horizontal sync pixels
  hb = 128      'horizontal back porch pixels
  vf = 9        'vertical front porch lines
  vs = 3        'vertical sync lines
  vb = 28       'vertical back porch lines
  hn = 1        'horizontal normal sync state (0|1)
  vn = 1        'vertical normal sync state (0|1)
  pr = 30       'pixel rate in MHz at 80MHz system clock (5MHz granularity)
 

Hi,

wrt my previous comment, I found your "VGA_Text" demo program which displays 32x15 characters. This could fit well into the "HiRes_Text" I'm using, but the assembly code looks very different, and uses only the internal ROM characters and not the modified font array characters. I wouldn't know where to start.

Is it possible to integrate the two? To be able to use the "VGA-Text" resolution within "Serial-VGA" program?

Thanks