MEGA65 / mega65-core

MEGA65 FPGA core
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VIC-IV bug when drawing first raster of char row #602

Open ki-bo opened 2 years ago

ki-bo commented 2 years ago

Test Environment (required)

Describe the bug When making the raster directly above the first row of characters visible, one can see that the first raster line of the first char row is actually drawn twice. This can be identified by either a) opening the top border a little so the raster above the first char row becomes visible; or b) increasing the TEXTYPOS a little to achieve the same

To Reproduce Steps to reproduce the behavior: Variant A to reproduce:

  1. POKE$D04E,$6A
  2. Type some letters into the top row of the screen.

Variant B to reproduce:

  1. POKE$D048,$60
  2. Type some letters into the top row of the screen.

Expected behavior The letters in the first row should be rendered as any other row on screen.

Screenshots See attached screenshots and notice the artefacts on the first row of characters.

IMG_9817 IMG_9818

lydon42 commented 1 year ago

confirmed on mega65r3.