diff --git a/Machines/Enterprise/Nick.cpp b/Machines/Enterprise/Nick.cpp
index 5bbccb201..2d5712fe4 100644
--- a/Machines/Enterprise/Nick.cpp
+++ b/Machines/Enterprise/Nick.cpp
@@ -86,7 +86,8 @@ uint8_t Nick::read([[maybe_unused]] uint16_t address) {
void Nick::run_for(Cycles duration) {
constexpr int line_length = 912;
-#define check_margins() \
+#define add_window(x) \
+ window += x; \
if(window == left_margin_) is_sync_or_pixels_ = true; \
if(window == right_margin_) is_sync_or_pixels_ = false;
@@ -117,16 +118,15 @@ void Nick::run_for(Cycles duration) {
switch(window) {
// First slot: line count, mode and interrupt flag.
case 0:
- assert(!(line_parameter_pointer_&0xf));
+ // Byte 0: lines remaining.
lines_remaining_ = ram_[line_parameter_pointer_];
- ++line_parameter_pointer_;
// Set the new interrupt line output.
- interrupt_line_ = ram_[line_parameter_pointer_] & 0x80;
+ interrupt_line_ = ram_[line_parameter_pointer_ + 1] & 0x80;
// Determine the mode and depth, and hence the column size.
- mode_ = Mode((ram_[line_parameter_pointer_] >> 1)&7);
- bpp_ = 1 << ((ram_[line_parameter_pointer_] >> 5)&3);
+ mode_ = Mode((ram_[line_parameter_pointer_ + 1] >> 1)&7);
+ bpp_ = 1 << ((ram_[line_parameter_pointer_ + 1] >> 5)&3);
switch(mode_) {
default:
case Mode::Pixel:
@@ -156,16 +156,15 @@ void Nick::run_for(Cycles duration) {
break;
}
- vres_ = ram_[line_parameter_pointer_] & 0x10;
- reload_line_parameter_pointer_ = ram_[line_parameter_pointer_] & 0x01;
- ++line_parameter_pointer_;
+ vres_ = ram_[line_parameter_pointer_ + 1] & 0x10;
+ reload_line_parameter_pointer_ = ram_[line_parameter_pointer_ + 1] & 0x01;
break;
// Second slot: margins and ALT/IND bits.
case 1:
// Determine the margins.
- left_margin_ = ram_[line_parameter_pointer_] & 0x3f;
- right_margin_ = ram_[(line_parameter_pointer_+1) & 0xffff] & 0x3f;
+ left_margin_ = ram_[line_parameter_pointer_ + 2] & 0x3f;
+ right_margin_ = ram_[line_parameter_pointer_ + 3] & 0x3f;
// Set up the alternative palettes,
switch(mode_) {
@@ -176,7 +175,7 @@ void Nick::run_for(Cycles duration) {
case Mode::Pixel:
case Mode::LPixel: {
- const uint8_t flags = ram_[line_parameter_pointer_];
+ const uint8_t flags = ram_[line_parameter_pointer_ + 2];
// Use MSBALT and LSBALT to pick the alt_ind_palettes.
//
@@ -194,7 +193,7 @@ void Nick::run_for(Cycles duration) {
case Mode::CH64:
case Mode::CH128:
case Mode::CH256: {
- const uint8_t flags = ram_[(line_parameter_pointer_+1) & 0xffff];
+ const uint8_t flags = ram_[line_parameter_pointer_ + 3];
// Use ALTIND0 and ALTIND1 to pick the alt_ind_palettes.
//
@@ -207,26 +206,20 @@ void Nick::run_for(Cycles duration) {
alt_ind_palettes[3] = alt_ind_palettes[2] + ((flags & 0x80) ? 4 : 0);
} break;
}
-
- line_parameter_pointer_ += 2;
break;
// Third slot: Line data pointer 1.
case 2:
- start_line_data_pointer_[0] = ram_[line_parameter_pointer_];
- ++line_parameter_pointer_;
- start_line_data_pointer_[0] |= ram_[line_parameter_pointer_] << 8;
- ++line_parameter_pointer_;
+ start_line_data_pointer_[0] = ram_[line_parameter_pointer_ + 4];
+ start_line_data_pointer_[0] |= ram_[line_parameter_pointer_ + 5] << 8;
line_data_pointer_[0] = start_line_data_pointer_[0];
break;
// Fourth slot: Line data pointer 2.
case 3:
- start_line_data_pointer_[1] = ram_[line_parameter_pointer_];
- ++line_parameter_pointer_;
- start_line_data_pointer_[1] |= ram_[line_parameter_pointer_] << 8;
- ++line_parameter_pointer_;
+ start_line_data_pointer_[1] = ram_[line_parameter_pointer_ + 6];
+ start_line_data_pointer_[1] |= ram_[line_parameter_pointer_ + 7] << 8;
line_data_pointer_[1] = start_line_data_pointer_[1];
break;
@@ -234,14 +227,10 @@ void Nick::run_for(Cycles duration) {
}
++output_duration_;
- ++window;
- check_margins();
+ add_window(1);
}
if(window == 4) {
if(mode_ == Mode::Vsync) {
- // Skip the palette.
- if(should_reload_line_parameters_) line_parameter_pointer_ += 8;
- should_reload_line_parameters_ = false;
set_output_type(is_sync_or_pixels_ ? OutputType::Sync : OutputType::Blank);
} else {
set_output_type(OutputType::Blank);
@@ -256,10 +245,9 @@ void Nick::run_for(Cycles duration) {
int next_event = end_window;
if(window < left_margin_) next_event = std::min(next_event, left_margin_);
if(window < right_margin_) next_event = std::min(next_event, right_margin_);
- output_duration_ += next_event - window;
- window = next_event;
- check_margins();
+ output_duration_ += next_event - window;
+ add_window(next_event - window);
set_output_type(is_sync_or_pixels_ ? OutputType::Sync : OutputType::Blank);
}
}
@@ -275,20 +263,18 @@ void Nick::run_for(Cycles duration) {
if(should_reload_line_parameters_ && window < 8) {
const int base = (window - 4) << 1;
- palette_[base] = mapped_colour(ram_[line_parameter_pointer_]);
- ++line_parameter_pointer_;
- palette_[base+1] = mapped_colour(ram_[line_parameter_pointer_]);
- ++line_parameter_pointer_;
- } else {
- should_reload_line_parameters_ = false;
+ palette_[base] = mapped_colour(ram_[line_parameter_pointer_ + base + 8]);
+ palette_[base + 1] = mapped_colour(ram_[line_parameter_pointer_ + base + 9]);
}
++output_duration_;
- ++window;
+ add_window(1);
}
if(window >= 10) {
- if(window == 10) set_output_type(is_sync_or_pixels_ ? OutputType::Pixels : OutputType::Border);
+ if(window == 10) {
+ set_output_type(is_sync_or_pixels_ ? OutputType::Pixels : OutputType::Border);
+ }
while(window < end_window) {
int next_event = end_window;
@@ -363,8 +349,7 @@ void Nick::run_for(Cycles duration) {
output_duration_ += next_event - window;
}
- window = next_event;
- check_margins();
+ add_window(next_event - window);
set_output_type(is_sync_or_pixels_ ? OutputType::Pixels : OutputType::Border);
}
}
@@ -372,7 +357,6 @@ void Nick::run_for(Cycles duration) {
// Check for end of line.
if(!horizontal_counter_) {
-// ++c;
++lines_remaining_;
if(!lines_remaining_) {
should_reload_line_parameters_ = true;
@@ -380,7 +364,11 @@ void Nick::run_for(Cycles duration) {
// Check for end-of-frame.
if(reload_line_parameter_pointer_) {
line_parameter_pointer_ = line_parameter_base_;
+ } else {
+ line_parameter_pointer_ += 16;
}
+ } else {
+ should_reload_line_parameters_ = false;
}
// Deal with VRES and other address reloading, dependant upon mode.
@@ -410,6 +398,9 @@ void Nick::run_for(Cycles duration) {
}
}
}
+
+#undef add_window
+
}
void Nick::set_output_type(OutputType type, bool force_flush) {