From 8fdf0405adf9017553d932412b98fc71dbbcf2f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Deuc=D0=B5?= <shurd@sasktel.net>
Date: Sat, 15 Feb 2025 03:44:27 -0500
Subject: [PATCH] Base the Prestel/Mode 7 aspect ratio on actual math
It's a bit different than straight 4:3 due to Mode 7 not using the
full line period or all the lines.
---
src/conio/vidmodes.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/conio/vidmodes.c b/src/conio/vidmodes.c
index 8555860180..6fdb858af7 100644
--- a/src/conio/vidmodes.c
+++ b/src/conio/vidmodes.c
@@ -125,7 +125,10 @@ struct video_params vparams[] = {
/* DigitalMon */
{LCD80X25, COLOUR_PALETTE, 80, 25, 14, 15, 16, 8, 7, 0, 8, 5, 640, 400},
/* Prestel */
- {PRESTEL_40X25, PRESTEL_PALETTE, 40, 25, 14, 15, 20, 12, 7, 0, 4, 3, 480, 500},
+ // Video data is transmitted for 40us of the 52us available to PAL.
+ // There's 500 lines of the 625 available to PAL
+ // This gives a 3077:2400 aspect ratio
+ {PRESTEL_40X25, PRESTEL_PALETTE, 40, 25, 14, 15, 20, 12, 7, 0, 3077, 2400, 480, 500},
/* Atari ST 40X25 */
{ATARIST_40X25, ATARI_PALETTE_16, 40, 25, 0, 7, 8, 8, 15, CIOLIB_VIDEO_BGBRIGHT | CIOLIB_VIDEO_NOBLINK, 4, 3, 320, 200},
/* Atari ST 80X25 */
--
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