From 17c13624e5959de290408d47cc053002026d4654 Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Sun, 27 Aug 2017 18:11:40 -0400 Subject: [PATCH] Improved comments. --- Components/6845/CRTC6845.hpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/Components/6845/CRTC6845.hpp b/Components/6845/CRTC6845.hpp index dcb3d718d..22b95ee4b 100644 --- a/Components/6845/CRTC6845.hpp +++ b/Components/6845/CRTC6845.hpp @@ -130,7 +130,8 @@ template class CRTC6845 { } // check for end of horizontal sync; note that a sync time of zero will result in an immediate - // cancellation of the plan to perform sync + // cancellation of the plan to perform sync if this is an HD6845S or UM6845R; otherwise zero + // will end up counting as 16 as it won't be checked until after overflow. if(bus_state_.hsync) { switch(personality_) { case HD6845S: @@ -168,6 +169,8 @@ template class CRTC6845 { // check for end of vertical sync if(bus_state_.vsync) { vsync_counter_ = (vsync_counter_ + 1) & 15; + // on the UM6845R and AMS40226, honour the programmed vertical sync time; on the other CRTCs + // always use a vertical sync count of 16. switch(personality_) { case HD6845S: case AMS40226: