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Switches to an is-in-video test that allows for video memory being paged twice.

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This is trivially possible even in plain 128kb mode.
This commit is contained in:
Thomas Harte 2021-03-22 15:46:02 -04:00
parent 8dbc7649aa
commit a26716919c
1 changed files with 6 additions and 8 deletions
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14
Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp
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@ -169,7 +169,7 @@ template<Model model> class ConcreteMachine:
case PartialMachineCycle::Write:
// Flush video if this access modifies screen contents.
if(address >= video_base_ && address < video_base_ + 6912) {
if(is_video_[address >> 14] && (address & 0x3fff) < 6912) {
video_.flush();
}
write_pointers_[address >> 14][address] = *cycle.value;
@ -386,7 +386,7 @@ template<Model model> class ConcreteMachine:
uint8_t *write_pointers_[4];
uint8_t pages_[4];
bool is_contended_[4];
int video_base_ = 0x4000;
bool is_video_[4];
uint8_t port1ffd_ = 0;
uint8_t port7ffd_ = 0;
@ -459,12 +459,10 @@ template<Model model> class ConcreteMachine:
void update_video_base() {
const uint8_t video_page = (port7ffd_ & 0x08) ? 7 : 5;
video_base_ = 0x1'0000; // i.e. not in memory.
if(pages_[0] == video_page) video_base_ = 0x0000;
else if(pages_[1] == video_page) video_base_ = 0x4000;
else if(pages_[2] == video_page) video_base_ = 0x8000;
else if(pages_[3] == video_page) video_base_ = 0xc000;
is_video_[0] = pages_[0] == video_page;
is_video_[1] = pages_[1] == video_page;
is_video_[2] = pages_[2] == video_page;
is_video_[3] = pages_[3] == video_page;
}
// MARK: - Audio.