From 71cf63bd35ca5b63c37cb4427dac3ea29463c461 Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Thu, 15 Apr 2021 19:17:11 -0400 Subject: [PATCH] Corrects internal cycle contention. --- Machines/Sinclair/ZXSpectrum/Video.hpp | 10 +--------- Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp | 1 + 2 files changed, 2 insertions(+), 9 deletions(-) diff --git a/Machines/Sinclair/ZXSpectrum/Video.hpp b/Machines/Sinclair/ZXSpectrum/Video.hpp index a37536f00..7ac67758c 100644 --- a/Machines/Sinclair/ZXSpectrum/Video.hpp +++ b/Machines/Sinclair/ZXSpectrum/Video.hpp @@ -122,13 +122,9 @@ template class Video { .cycles_per_line = 228 * 2, .lines_per_frame = 311, - // i.e. video fetching begins five cycles after the start of the - // contended memory pattern below; that should put a clear two - // cycles between a Z80 access and the first video fetch. .contention_leadin = 5 * 2, .contention_duration = 128 * 2, - // i.e. interrupt is first signalled 14368 cycles before the first video fetch. .interrupt_time = (228*311 - 14361) * 2, .delays = { @@ -151,14 +147,10 @@ template class Video { .cycles_per_line = 224 * 2, .lines_per_frame = 312, - // i.e. video fetching begins five cycles after the start of the - // contended memory pattern below; that should put a clear two - // cycles between a Z80 access and the first video fetch. .contention_leadin = 5 * 2, .contention_duration = 128 * 2, - // i.e. interrupt is first signalled 14368 cycles before the first video fetch. - .interrupt_time = (224*312 - 14361) * 2, + .interrupt_time = (224*312 - 14330) * 2, .delays = { 12, 11, diff --git a/Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp b/Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp index d8f5109e7..dd82ab0ac 100644 --- a/Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp +++ b/Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp @@ -281,6 +281,7 @@ template class ConcreteMachine: time += next_delay + 2; } + advance(cycle.length + delay); return delay; } }