From 020a04006e7c0f54862434d5f685ed1669eb6f07 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 18 Mar 2021 23:07:51 -0400
Subject: [PATCH] Adds flashing, randomises initial RAM contents.
---
Machines/Sinclair/ZXSpectrum/Video.hpp | 13 ++++++++++++-
Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp | 3 +++
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/Machines/Sinclair/ZXSpectrum/Video.hpp b/Machines/Sinclair/ZXSpectrum/Video.hpp
index 72c46e914..e24aed551 100644
--- a/Machines/Sinclair/ZXSpectrum/Video.hpp
+++ b/Machines/Sinclair/ZXSpectrum/Video.hpp
@@ -89,6 +89,12 @@ template <VideoTiming timing> class Video {
const int cycles_this_line = std::min(cycles_remaining, timings.cycles_per_line - offset);
const int end_offset = offset + cycles_this_line;
+ if(!line && !offset) {
+ ++flash_counter_;
+ flash_mask_ = uint8_t(flash_counter_ >> 4);
+ flash_counter_ &= 31;
+ }
+
if(line < 3) {
// Output sync line.
crt_.output_sync(cycles_this_line);
@@ -127,9 +133,11 @@ template <VideoTiming timing> class Video {
const int start_column = offset >> 3;
const int end_column = (offset + pixel_duration) >> 3;
for(int column = start_column; column < end_column; column++) {
- const uint8_t pixels = memory_[pixel_address_];
const uint8_t attributes = memory_[attribute_address_];
+ constexpr uint8_t masks[] = {0, 0xff};
+ const uint8_t pixels = memory_[pixel_address_] ^ masks[flash_mask_ & (attributes >> 7)];
+
const uint8_t colours[2] = {
palette[((attributes & 0x40) >> 3) | (attributes & 0x07)],
palette[(attributes & 0x78) >> 3],
@@ -255,6 +263,9 @@ template <VideoTiming timing> class Video {
int attribute_address_ = 0;
int pixel_address_ = 0;
+ uint8_t flash_mask_ = 0;
+ int flash_counter_ = 0;
+
#define RGB(r, g, b) (r << 4) | (g << 2) | b
static constexpr uint8_t palette[] = {
RGB(0, 0, 0), RGB(0, 0, 2), RGB(2, 0, 0), RGB(2, 0, 2),
diff --git a/Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp b/Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp
index 638565e57..ce649eaa9 100644
--- a/Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp
+++ b/Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp
@@ -26,6 +26,8 @@
#include "../../../Analyser/Static/ZXSpectrum/Target.hpp"
+#include "../../Utility/MemoryFuzzer.hpp"
+
#include "../../../ClockReceiver/JustInTime.hpp"
#include <array>
@@ -60,6 +62,7 @@ template<Model model> class ConcreteMachine:
// Set up initial memory map.
update_memory_map();
+ Memory::Fuzz(ram_);
// TODO: insert media.
(void)target;