From 4cb7abe13d49f749b5791add1d91c8e54567622e Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 18 May 2023 16:28:05 -0400
Subject: [PATCH 1/7] Update old comment.
---
Components/9918/Implementation/Fetch.hpp | 33 +++++-------------------
1 file changed, 7 insertions(+), 26 deletions(-)
diff --git a/Components/9918/Implementation/Fetch.hpp b/Components/9918/Implementation/Fetch.hpp
index efb972617..41ba56cec 100644
--- a/Components/9918/Implementation/Fetch.hpp
+++ b/Components/9918/Implementation/Fetch.hpp
@@ -16,38 +16,19 @@ namespace TI::TMS {
1) input is a start position and an end position; they should perform the proper
operations for the period: start <= time < end.
- 2) times are measured relative to a 172-cycles-per-line clock (so: they directly
- count access windows on the TMS and Master System).
- 3) within each sequencer, time 0 is the access window that straddles the beginning of
- horizontal sync. Which, conveniently, is the place to which Grauw's timing diagrams
- are aligned.
+ 2) times are measured relative to the an appropriate clock — they directly
+ count access windows on the TMS and Master System, and cycles on a Yamaha.
+ 3) within each sequencer, cycle are numbered as per Grauw's timing diagrams. The difference
+ between those and internal timing, if there is one, is handled by the dispatcher.
4) all of these functions are templated with a `use_end` parameter. That will be true if
- end is < 172, false otherwise. So functions can use it to eliminate should-exit-not checks,
- for the more usual path of execution.
-
- [Historically:
- position 0 was the beginning of the access window immediately after the last pattern/data
- block fetch that would contribute to this line, in a normal 32-column mode. So:
-
- * it's cycle 309 on Mattias' TMS diagram;
- * it's cycle 1238 on his V9938 diagram;
- * it's after the last background render block in Mask of Destiny's Master System timing diagram.
-
- That division point was selected, albeit arbitrarily, because it puts all the tile
- fetches for a single line into the same [0, 171] period.
-
- I'm moving away from this per the desire not to have V9938 output straddle two lines if horizontally-adjusted,
- amongst other concerns.]
+ end is < [cycles per line], false otherwise. So functions can use it to eliminate
+ should-exit-now checks (which is likely to be the more usual path of execution).
Provided for the benefit of the methods below:
* the function external_slot(), which will perform any pending VRAM read/write.
- * the macros slot(n) and external_slot(n) which can be used to schedule those things inside a
- switch(start)-based implementation.
- All functions should just spool data to intermediary storage. This is because for most VDPs there is
- a decoupling between fetch pattern and output pattern, and it's neater to keep the same division
- for the exceptions.
+ All functions should just spool data to intermediary storage. Fetching and drawing are decoupled.
*/
// MARK: - Address mask helpers.
From c76048bff90b13e639271989ccd8a18eb38697c3 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 18 May 2023 16:37:48 -0400
Subject: [PATCH 2/7] Formalise the idea of Grauw as a separate clock.
---
.../9918/Implementation/ClockConverter.hpp | 86 ++++---------------
Components/9918/Implementation/LineLayout.hpp | 82 ++++++++++++++++++
.../Clock Signal.xcodeproj/project.pbxproj | 2 +
3 files changed, 102 insertions(+), 68 deletions(-)
create mode 100644 Components/9918/Implementation/LineLayout.hpp
diff --git a/Components/9918/Implementation/ClockConverter.hpp b/Components/9918/Implementation/ClockConverter.hpp
index d76746aa7..c4e692ce6 100644
--- a/Components/9918/Implementation/ClockConverter.hpp
+++ b/Components/9918/Implementation/ClockConverter.hpp
@@ -11,14 +11,21 @@
#include "../9918.hpp"
#include "PersonalityTraits.hpp"
+#include "LineLayout.hpp"
namespace TI::TMS {
enum class Clock {
+ /// Whatever rate this VDP runs at, with location 0 being "the start" of the line per internal preference.
Internal,
+ /// A 342-cycle/line clock with the same start position as ::Internal.
TMSPixel,
+ /// A 171-cycle/line clock that begins at the memory window which starts straight after ::Internal = 0.
TMSMemoryWindow,
- CRT
+ /// A fixed 1368-cycle/line clock that is used to count output to the CRT.
+ CRT,
+ /// Provides the same clock rate as ::Internal but is relocated so that 0 is where Grauw put 0 (i.e. at the start of horizontal sync).
+ Grauw,
};
template <Personality personality, Clock clk> constexpr int clock_rate() {
@@ -33,6 +40,7 @@ template <Personality personality, Clock clk> constexpr int clock_rate() {
case Clock::TMSMemoryWindow: return 171;
case Clock::CRT: return 1368;
case Clock::Internal:
+ case Clock::Grauw:
if constexpr (is_classic_vdp(personality)) {
return 342;
} else if constexpr (is_yamaha_vdp(personality)) {
@@ -43,17 +51,25 @@ template <Personality personality, Clock clk> constexpr int clock_rate() {
}
}
+/// Statelessly converts @c length in @c clock to the internal clock used by VDPs of @c personality throwing away any remainder.
template <Personality personality, Clock clock> constexpr int to_internal(int length) {
+ if constexpr (clock == Clock::Grauw) {
+ return (length + LineLayout<personality>::LocationOfGrauwZero) % LineLayout<personality>::CyclesPerLine;
+ }
return length * clock_rate<personality, Clock::Internal>() / clock_rate<personality, clock>();
}
+/// Statelessly converts @c length to @c clock from the the internal clock used by VDPs of @c personality throwing away any remainder.
template <Personality personality, Clock clock> constexpr int from_internal(int length) {
+ if constexpr (clock == Clock::Grauw) {
+ return (length + LineLayout<personality>::CyclesPerLine - LineLayout<personality>::LocationOfGrauwZero) % LineLayout<personality>::CyclesPerLine;
+ }
return length * clock_rate<personality, clock>() / clock_rate<personality, Clock::Internal>();
}
/*!
Provides a [potentially-]stateful conversion between the external and internal clocks.
- Unlike the other clock conversions, this one may be non-integral, requiring that
+ Unlike the other clock conversions, this may be non-integral, requiring that
an error term be tracked.
*/
template <Personality personality> class ClockConverter {
@@ -130,72 +146,6 @@ template <Personality personality> class ClockConverter {
int cycles_error_ = 0;
};
-
-//
-//
-//
-template <Personality personality, typename Enable = void> struct LineLayout;
-
-// Line layout is:
-//
-// [0, EndOfSync] sync
-// (EndOfSync, StartOfColourBurst] blank
-// (StartOfColourBurst, EndOfColourBurst] colour burst
-// (EndOfColourBurst, EndOfLeftErase] blank
-// (EndOfLeftErase, EndOfLeftBorder] border colour
-// (EndOfLeftBorder, EndOfPixels] pixel content
-// (EndOfPixels, EndOfRightBorder] border colour
-// [EndOfRightBorder, <end of line>] blank
-//
-// ... with minor caveats:
-// * horizontal adjust on the Yamaha VDPs is applied to EndOfLeftBorder and EndOfPixels;
-// * the Sega VDPs may programatically extend the left border; and
-// * text mode on all VDPs adjusts border width.
-
-template <Personality personality> struct LineLayout<personality, std::enable_if_t<is_classic_vdp(personality)>> {
- constexpr static int EndOfSync = 26;
- constexpr static int StartOfColourBurst = 29;
- constexpr static int EndOfColourBurst = 43;
- constexpr static int EndOfLeftErase = 50;
- constexpr static int EndOfLeftBorder = 63;
- constexpr static int EndOfPixels = 319;
- constexpr static int EndOfRightBorder = 334;
-
- constexpr static int CyclesPerLine = 342;
-
- constexpr static int TextModeEndOfLeftBorder = 69;
- constexpr static int TextModeEndOfPixels = 309;
-
- constexpr static int ModeLatchCycle = 36; // Just a guess; correlates with the known 144 for the Yamaha VDPs,
- // and falls into the collection gap between the final sprite
- // graphics and the initial tiles or pixels.
-
- /// The number of internal cycles that must elapse between a request to read or write and
- /// it becoming a candidate for action.
- constexpr static int VRAMAccessDelay = 6;
-};
-
-template <Personality personality> struct LineLayout<personality, std::enable_if_t<is_yamaha_vdp(personality)>> {
- constexpr static int EndOfSync = 100;
- constexpr static int StartOfColourBurst = 113;
- constexpr static int EndOfColourBurst = 167;
- constexpr static int EndOfLeftErase = 202;
- constexpr static int EndOfLeftBorder = 258;
- constexpr static int EndOfPixels = 1282;
- constexpr static int EndOfRightBorder = 1341;
-
- constexpr static int CyclesPerLine = 1368;
-
- constexpr static int TextModeEndOfLeftBorder = 294;
- constexpr static int TextModeEndOfPixels = 1254;
-
- constexpr static int ModeLatchCycle = 144;
-
- /// The number of internal cycles that must elapse between a request to read or write and
- /// it becoming a candidate for action.
- constexpr static int VRAMAccessDelay = 16;
-};
-
}
#endif /* ClockConverter_hpp */
diff --git a/Components/9918/Implementation/LineLayout.hpp b/Components/9918/Implementation/LineLayout.hpp
new file mode 100644
index 000000000..c8509b505
--- /dev/null
+++ b/Components/9918/Implementation/LineLayout.hpp
@@ -0,0 +1,82 @@
+//
+// LineLayout.hpp
+// Clock Signal
+//
+// Created by Thomas Harte on 18/05/2023.
+// Copyright © 2023 Thomas Harte. All rights reserved.
+//
+
+#ifndef LineLayout_h
+#define LineLayout_h
+
+namespace TI::TMS {
+
+template <Personality personality, typename Enable = void> struct LineLayout;
+
+// Line layout is:
+//
+// [0, EndOfSync] sync
+// (EndOfSync, StartOfColourBurst] blank
+// (StartOfColourBurst, EndOfColourBurst] colour burst
+// (EndOfColourBurst, EndOfLeftErase] blank
+// (EndOfLeftErase, EndOfLeftBorder] border colour
+// (EndOfLeftBorder, EndOfPixels] pixel content
+// (EndOfPixels, EndOfRightBorder] border colour
+// [EndOfRightBorder, <end of line>] blank
+//
+// ... with minor caveats:
+// * horizontal adjust on the Yamaha VDPs is applied to EndOfLeftBorder and EndOfPixels;
+// * the Sega VDPs may programatically extend the left border; and
+// * text mode on all VDPs adjusts border width.
+
+template <Personality personality> struct LineLayout<personality, std::enable_if_t<is_classic_vdp(personality)>> {
+ constexpr static int EndOfSync = 26;
+ constexpr static int StartOfColourBurst = 29;
+ constexpr static int EndOfColourBurst = 43;
+ constexpr static int EndOfLeftErase = 50;
+ constexpr static int EndOfLeftBorder = 63;
+ constexpr static int EndOfPixels = 319;
+ constexpr static int EndOfRightBorder = 334;
+
+ constexpr static int CyclesPerLine = 342;
+
+ constexpr static int TextModeEndOfLeftBorder = 69;
+ constexpr static int TextModeEndOfPixels = 309;
+
+ constexpr static int ModeLatchCycle = 36; // Just a guess; correlates with the known 144 for the Yamaha VDPs,
+ // and falls into the collection gap between the final sprite
+ // graphics and the initial tiles or pixels.
+
+ constexpr static int LocationOfGrauwZero = 0;
+
+ /// The number of internal cycles that must elapse between a request to read or write and
+ /// it becoming a candidate for action.
+ constexpr static int VRAMAccessDelay = 6;
+};
+
+template <Personality personality> struct LineLayout<personality, std::enable_if_t<is_yamaha_vdp(personality)>> {
+ constexpr static int EndOfSync = 100;
+ constexpr static int StartOfColourBurst = 113;
+ constexpr static int EndOfColourBurst = 167;
+ constexpr static int EndOfLeftErase = 202;
+ constexpr static int EndOfLeftBorder = 258;
+ constexpr static int EndOfPixels = 1282;
+ constexpr static int EndOfRightBorder = 1341;
+
+ constexpr static int CyclesPerLine = 1368;
+
+ constexpr static int TextModeEndOfLeftBorder = 294;
+ constexpr static int TextModeEndOfPixels = 1254;
+
+ constexpr static int ModeLatchCycle = 144;
+
+ constexpr static int LocationOfGrauwZero = 0;
+
+ /// The number of internal cycles that must elapse between a request to read or write and
+ /// it becoming a candidate for action.
+ constexpr static int VRAMAccessDelay = 16;
+};
+
+}
+
+#endif /* LineLayout_h */
diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
index 3e16aa8a5..75e1fd830 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
@@ -1100,6 +1100,7 @@
/* End PBXCopyFilesBuildPhase section */
/* Begin PBXFileReference section */
+ 428168372A16C25C008ECD27 /* LineLayout.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = LineLayout.hpp; sourceTree = "<group>"; };
42AD552E2A0C4D5000ACE410 /* 68000.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = 68000.hpp; sourceTree = "<group>"; };
42AD55302A0C4D5000ACE410 /* 68000Storage.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = 68000Storage.hpp; sourceTree = "<group>"; };
42AD55312A0C4D5000ACE410 /* 68000Implementation.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = 68000Implementation.hpp; sourceTree = "<group>"; };
@@ -4738,6 +4739,7 @@
4B43983F2967459B006B0BFC /* Draw.hpp */,
4B43983E29628538006B0BFC /* Fetch.hpp */,
4B2A3B5B29995FF6007CE366 /* LineBuffer.hpp */,
+ 428168372A16C25C008ECD27 /* LineLayout.hpp */,
4B262BFF29691F55002EC0F7 /* PersonalityTraits.hpp */,
4B2A3B5A29993DFA007CE366 /* Storage.hpp */,
4BF0BC732982E54700CCA2B5 /* YamahaCommands.hpp */,
From ce8bd011d702dbce6bbcf111cfe02d84ba317630 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 18 May 2023 16:50:46 -0400
Subject: [PATCH 3/7] Add commentary, and TODOs.
---
Components/9918/Implementation/9918.cpp | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/Components/9918/Implementation/9918.cpp b/Components/9918/Implementation/9918.cpp
index 34af6a73b..7011e3681 100644
--- a/Components/9918/Implementation/9918.cpp
+++ b/Components/9918/Implementation/9918.cpp
@@ -35,12 +35,16 @@ Base<personality>::Base() :
// "For a line interrupt, /INT is pulled low 608 mclks into the appropriate scanline relative to pixel 0.
// This is 3 mclks before the rising edge of /HSYNC which starts the next scanline."
+ //
+ // i.e. it's 304 internal clocks after the end of the left border.
mode_timing_.line_interrupt_position = (LineLayout<personality>::EndOfLeftBorder + 304) % LineLayout<personality>::CyclesPerLine;
// For a frame interrupt, /INT is pulled low 607 mclks into scanline 192 (of scanlines 0 through 261) relative to pixel 0.
// This is 4 mclks before the rising edge of /HSYNC which starts the next scanline.
+ //
+ // i.e. it's 1/2 cycle before the line interrupt position, which I have rounded. Ugh.
mode_timing_.end_of_frame_interrupt_position.column = mode_timing_.line_interrupt_position - 1;
- mode_timing_.end_of_frame_interrupt_position.row = 193;
+ mode_timing_.end_of_frame_interrupt_position.row = 192 + (LineLayout<personality>::EndOfLeftBorder + 304) / LineLayout<personality>::CyclesPerLine;
}
if constexpr (is_yamaha_vdp(personality)) {
@@ -81,6 +85,7 @@ TMS9918<personality>::TMS9918() {
template <Personality personality>
void TMS9918<personality>::set_tv_standard(TVStandard standard) {
+ // TODO: the Yamaha is programmable on this at runtime.
this->tv_standard_ = standard;
switch(standard) {
case TVStandard::PAL:
@@ -214,8 +219,10 @@ void TMS9918<personality>::run_for(const HalfCycles cycles) {
// ---------------------------------------
// Latch scrolling position, if necessary.
// ---------------------------------------
+ // TODO: shouldn't this happen one per frame?
if constexpr (is_sega_vdp(personality)) {
- if(this->fetch_pointer_.column < 61 && end_column >= 61) {
+ constexpr auto latch_time = to_internal<personality, Clock::Grauw>(61); // TODO: where did this magic constant come from? Is it the same for the Game Gear, etc?
+ if(this->fetch_pointer_.column < latch_time && end_column >= latch_time) {
if(!this->fetch_pointer_.row) {
Storage<personality>::latched_vertical_scroll_ = Storage<personality>::vertical_scroll_;
From dc425a03d3fa1c0ba4ab36c0ae27b63df1f735e5 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 18 May 2023 16:55:17 -0400
Subject: [PATCH 4/7] Partially resolve.
---
Components/9918/Implementation/9918.cpp | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/Components/9918/Implementation/9918.cpp b/Components/9918/Implementation/9918.cpp
index 7011e3681..b8a589e35 100644
--- a/Components/9918/Implementation/9918.cpp
+++ b/Components/9918/Implementation/9918.cpp
@@ -219,11 +219,14 @@ void TMS9918<personality>::run_for(const HalfCycles cycles) {
// ---------------------------------------
// Latch scrolling position, if necessary.
// ---------------------------------------
- // TODO: shouldn't this happen one per frame?
if constexpr (is_sega_vdp(personality)) {
- constexpr auto latch_time = to_internal<personality, Clock::Grauw>(61); // TODO: where did this magic constant come from? Is it the same for the Game Gear, etc?
- if(this->fetch_pointer_.column < latch_time && end_column >= latch_time) {
- if(!this->fetch_pointer_.row) {
+ if(!this->fetch_pointer_.row) {
+ // TODO: where did this magic constant come from? https://www.smspower.org/forums/17970-RoadRashHow#111000 mentioned in passing
+ // that "the vertical scroll register is latched at the start of the active display" and this is two clocks before that, so it's
+ // not uncompelling. I can just no longer find my source.
+ constexpr auto latch_time = LineLayout<personality>::EndOfLeftBorder - 2;
+ static_assert(latch_time > 0);
+ if(this->fetch_pointer_.column < latch_time && end_column >= latch_time) {
Storage<personality>::latched_vertical_scroll_ = Storage<personality>::vertical_scroll_;
if(Storage<personality>::mode4_enable_) {
@@ -242,7 +245,6 @@ void TMS9918<personality>::run_for(const HalfCycles cycles) {
}
-
// ------------------------
// Perform memory accesses.
// ------------------------
From d117a44069b603cbc57b6406081b0153e0f86fc6 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 19 May 2023 11:46:49 -0400
Subject: [PATCH 5/7] Allow for potential Grauw offset in TMS and SMS.
---
.../9918/Implementation/ClockConverter.hpp | 32 ++++++++++++-----
Components/9918/Implementation/Fetch.hpp | 36 +++++++++++--------
2 files changed, 44 insertions(+), 24 deletions(-)
diff --git a/Components/9918/Implementation/ClockConverter.hpp b/Components/9918/Implementation/ClockConverter.hpp
index c4e692ce6..9d73ccefc 100644
--- a/Components/9918/Implementation/ClockConverter.hpp
+++ b/Components/9918/Implementation/ClockConverter.hpp
@@ -51,20 +51,34 @@ template <Personality personality, Clock clk> constexpr int clock_rate() {
}
}
-/// Statelessly converts @c length in @c clock to the internal clock used by VDPs of @c personality throwing away any remainder.
-template <Personality personality, Clock clock> constexpr int to_internal(int length) {
- if constexpr (clock == Clock::Grauw) {
- return (length + LineLayout<personality>::LocationOfGrauwZero) % LineLayout<personality>::CyclesPerLine;
+/// Statelessly converts @c length to the internal clock for @c personality; applies conversions per the list of clocks in left-to-right order.
+template <Personality personality, Clock head, Clock... tail> constexpr int to_internal(int length) {
+ if constexpr (head == Clock::Grauw) {
+ length = (length + LineLayout<personality>::LocationOfGrauwZero) % LineLayout<personality>::CyclesPerLine;
+ } else {
+ length = length * clock_rate<personality, Clock::Internal>() / clock_rate<personality, head>();
+ }
+
+ if constexpr (!sizeof...(tail)) {
+ return length;
+ } else {
+ return to_internal<personality, tail...>(length);
}
- return length * clock_rate<personality, Clock::Internal>() / clock_rate<personality, clock>();
}
/// Statelessly converts @c length to @c clock from the the internal clock used by VDPs of @c personality throwing away any remainder.
-template <Personality personality, Clock clock> constexpr int from_internal(int length) {
- if constexpr (clock == Clock::Grauw) {
- return (length + LineLayout<personality>::CyclesPerLine - LineLayout<personality>::LocationOfGrauwZero) % LineLayout<personality>::CyclesPerLine;
+template <Personality personality, Clock head, Clock... tail> constexpr int from_internal(int length) {
+ if constexpr (head == Clock::Grauw) {
+ length = (length + LineLayout<personality>::CyclesPerLine - LineLayout<personality>::LocationOfGrauwZero) % LineLayout<personality>::CyclesPerLine;
+ } else {
+ length = length * clock_rate<personality, head>() / clock_rate<personality, Clock::Internal>();
+ }
+
+ if constexpr (!sizeof...(tail)) {
+ return length;
+ } else {
+ return to_internal<personality, tail...>(length);
}
- return length * clock_rate<personality, clock>() / clock_rate<personality, Clock::Internal>();
}
/*!
diff --git a/Components/9918/Implementation/Fetch.hpp b/Components/9918/Implementation/Fetch.hpp
index 41ba56cec..98d2b9320 100644
--- a/Components/9918/Implementation/Fetch.hpp
+++ b/Components/9918/Implementation/Fetch.hpp
@@ -54,7 +54,7 @@ template<bool use_end, typename SequencerT> void Base<personality>::dispatch(Seq
#define index(n) \
if(use_end && end == n) return; \
[[fallthrough]]; \
- case n: fetcher.template fetch<n>();
+ case n: fetcher.template fetch<from_internal<personality, Clock::Grauw>(n)>();
switch(start) {
default: assert(false);
@@ -373,7 +373,7 @@ struct RefreshSequencer {
template <int cycle> void fetch() {
if(cycle < 26 || (cycle & 1) || cycle >= 154) {
- base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
}
}
@@ -387,16 +387,22 @@ struct TextSequencer {
template <int cycle> void fetch() {
// The first 30 and the final 4 slots are external.
if constexpr (cycle < 30 || cycle >= 150) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
return;
} else {
// For the 120 slots in between follow a three-step pattern of:
constexpr int offset = cycle - 30;
constexpr auto column = AddressT(offset / 3);
switch(offset % 3) {
- case 0: fetcher.fetch_name(column); break; // (1) fetch tile name.
- case 1: fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle)); break; // (2) external slot.
- case 2: fetcher.fetch_pattern(column); break; // (3) fetch tile pattern.
+ case 0: // (1) fetch tile name.
+ fetcher.fetch_name(column);
+ break;
+ case 1: // (2) external slot.
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ break;
+ case 2: // (3) fetch tile pattern.
+ fetcher.fetch_pattern(column);
+ break;
}
}
}
@@ -413,7 +419,7 @@ struct CharacterSequencer {
template <int cycle> void fetch() {
if(cycle < 5) {
- character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
}
if(cycle == 5) {
@@ -424,7 +430,7 @@ struct CharacterSequencer {
}
if(cycle > 14 && cycle < 19) {
- character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
}
// Fetch 8 new sprite Y coordinates, to begin selecting sprites for next line.
@@ -442,7 +448,7 @@ struct CharacterSequencer {
case 0: character_fetcher.fetch_name(block); break;
case 1:
if(!(block & 3)) {
- character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
} else {
constexpr int sprite = 8 + ((block >> 2) * 3) + ((block & 3) - 1);
sprite_fetcher.fetch_y(sprite);
@@ -457,7 +463,7 @@ struct CharacterSequencer {
}
if(cycle >= 155 && cycle < 157) {
- character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
}
if(cycle == 157) {
@@ -505,7 +511,7 @@ struct SMSSequencer {
// window 0 to HSYNC low.
template <int cycle> void fetch() {
if(cycle < 3) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
}
if(cycle == 3) {
@@ -516,7 +522,7 @@ struct SMSSequencer {
}
if(cycle == 15 || cycle == 16) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
}
if(cycle == 17) {
@@ -537,7 +543,7 @@ struct SMSSequencer {
case 0: fetcher.fetch_tile_name(block); break;
case 1:
if(!(block & 3)) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
} else {
constexpr int sprite = (8 + ((block >> 2) * 3) + ((block & 3) - 1)) << 1;
fetcher.posit_sprite(sprite);
@@ -549,7 +555,7 @@ struct SMSSequencer {
}
if(cycle >= 153 && cycle < 157) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
}
if(cycle == 157) {
@@ -560,7 +566,7 @@ struct SMSSequencer {
}
if(cycle >= 169) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
}
}
From c75efb7dac72ff1d105f9460ef3e822d372dcdf3 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 19 May 2023 13:43:28 -0400
Subject: [PATCH 6/7] Also allow for a potential Grauw conversion in Yamaha
land.
---
Components/9918/Implementation/Storage.hpp | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/Components/9918/Implementation/Storage.hpp b/Components/9918/Implementation/Storage.hpp
index f0a0611b3..70a4bcd92 100644
--- a/Components/9918/Implementation/Storage.hpp
+++ b/Components/9918/Implementation/Storage.hpp
@@ -86,7 +86,8 @@ struct YamahaFetcher {
std::array<Event, size> result{};
size_t index = 0;
for(int c = 0; c < 1368; c++) {
- const auto event = GeneratorT::event(c);
+ // Specific personality doesn't matter here; both Yamahas use the same internal timing.
+ const auto event = GeneratorT::event(from_internal<Personality::V9938, Clock::Grauw>(c));
if(!event) {
continue;
}
From 40d5bd4e58a02e5157bf727f5d30cd98c1792a88 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 19 May 2023 14:22:22 -0400
Subject: [PATCH 7/7] Switch to purposive name.
---
.../9918/Implementation/ClockConverter.hpp | 17 +++++++-----
Components/9918/Implementation/Fetch.hpp | 26 +++++++++----------
Components/9918/Implementation/LineLayout.hpp | 6 ++---
Components/9918/Implementation/Storage.hpp | 4 +--
4 files changed, 27 insertions(+), 26 deletions(-)
diff --git a/Components/9918/Implementation/ClockConverter.hpp b/Components/9918/Implementation/ClockConverter.hpp
index 9d73ccefc..2aa9d840f 100644
--- a/Components/9918/Implementation/ClockConverter.hpp
+++ b/Components/9918/Implementation/ClockConverter.hpp
@@ -24,8 +24,9 @@ enum class Clock {
TMSMemoryWindow,
/// A fixed 1368-cycle/line clock that is used to count output to the CRT.
CRT,
- /// Provides the same clock rate as ::Internal but is relocated so that 0 is where Grauw put 0 (i.e. at the start of horizontal sync).
- Grauw,
+ /// Provides the same clock rate as ::Internal but is relocated so that 0 is the start of horizontal sync — very not coincidentally,
+ /// where Grauw puts 0 on his detailed TMS and Yamaha timing diagrams.
+ FromStartOfSync,
};
template <Personality personality, Clock clk> constexpr int clock_rate() {
@@ -40,7 +41,7 @@ template <Personality personality, Clock clk> constexpr int clock_rate() {
case Clock::TMSMemoryWindow: return 171;
case Clock::CRT: return 1368;
case Clock::Internal:
- case Clock::Grauw:
+ case Clock::FromStartOfSync:
if constexpr (is_classic_vdp(personality)) {
return 342;
} else if constexpr (is_yamaha_vdp(personality)) {
@@ -53,8 +54,8 @@ template <Personality personality, Clock clk> constexpr int clock_rate() {
/// Statelessly converts @c length to the internal clock for @c personality; applies conversions per the list of clocks in left-to-right order.
template <Personality personality, Clock head, Clock... tail> constexpr int to_internal(int length) {
- if constexpr (head == Clock::Grauw) {
- length = (length + LineLayout<personality>::LocationOfGrauwZero) % LineLayout<personality>::CyclesPerLine;
+ if constexpr (head == Clock::FromStartOfSync) {
+ length = (length + LineLayout<personality>::StartOfSync) % LineLayout<personality>::CyclesPerLine;
} else {
length = length * clock_rate<personality, Clock::Internal>() / clock_rate<personality, head>();
}
@@ -68,8 +69,10 @@ template <Personality personality, Clock head, Clock... tail> constexpr int to_i
/// Statelessly converts @c length to @c clock from the the internal clock used by VDPs of @c personality throwing away any remainder.
template <Personality personality, Clock head, Clock... tail> constexpr int from_internal(int length) {
- if constexpr (head == Clock::Grauw) {
- length = (length + LineLayout<personality>::CyclesPerLine - LineLayout<personality>::LocationOfGrauwZero) % LineLayout<personality>::CyclesPerLine;
+ if constexpr (head == Clock::FromStartOfSync) {
+ length =
+ (length + LineLayout<personality>::CyclesPerLine - LineLayout<personality>::StartOfSync)
+ % LineLayout<personality>::CyclesPerLine;
} else {
length = length * clock_rate<personality, head>() / clock_rate<personality, Clock::Internal>();
}
diff --git a/Components/9918/Implementation/Fetch.hpp b/Components/9918/Implementation/Fetch.hpp
index 98d2b9320..045770536 100644
--- a/Components/9918/Implementation/Fetch.hpp
+++ b/Components/9918/Implementation/Fetch.hpp
@@ -54,7 +54,7 @@ template<bool use_end, typename SequencerT> void Base<personality>::dispatch(Seq
#define index(n) \
if(use_end && end == n) return; \
[[fallthrough]]; \
- case n: fetcher.template fetch<from_internal<personality, Clock::Grauw>(n)>();
+ case n: fetcher.template fetch<from_internal<personality, Clock::FromStartOfSync>(n)>();
switch(start) {
default: assert(false);
@@ -373,7 +373,7 @@ struct RefreshSequencer {
template <int cycle> void fetch() {
if(cycle < 26 || (cycle & 1) || cycle >= 154) {
- base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
}
}
@@ -387,7 +387,7 @@ struct TextSequencer {
template <int cycle> void fetch() {
// The first 30 and the final 4 slots are external.
if constexpr (cycle < 30 || cycle >= 150) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
return;
} else {
// For the 120 slots in between follow a three-step pattern of:
@@ -398,7 +398,7 @@ struct TextSequencer {
fetcher.fetch_name(column);
break;
case 1: // (2) external slot.
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
break;
case 2: // (3) fetch tile pattern.
fetcher.fetch_pattern(column);
@@ -419,7 +419,7 @@ struct CharacterSequencer {
template <int cycle> void fetch() {
if(cycle < 5) {
- character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
}
if(cycle == 5) {
@@ -430,7 +430,7 @@ struct CharacterSequencer {
}
if(cycle > 14 && cycle < 19) {
- character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
}
// Fetch 8 new sprite Y coordinates, to begin selecting sprites for next line.
@@ -448,7 +448,7 @@ struct CharacterSequencer {
case 0: character_fetcher.fetch_name(block); break;
case 1:
if(!(block & 3)) {
- character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
} else {
constexpr int sprite = 8 + ((block >> 2) * 3) + ((block & 3) - 1);
sprite_fetcher.fetch_y(sprite);
@@ -463,7 +463,7 @@ struct CharacterSequencer {
}
if(cycle >= 155 && cycle < 157) {
- character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ character_fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
}
if(cycle == 157) {
@@ -511,7 +511,7 @@ struct SMSSequencer {
// window 0 to HSYNC low.
template <int cycle> void fetch() {
if(cycle < 3) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
}
if(cycle == 3) {
@@ -522,7 +522,7 @@ struct SMSSequencer {
}
if(cycle == 15 || cycle == 16) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
}
if(cycle == 17) {
@@ -543,7 +543,7 @@ struct SMSSequencer {
case 0: fetcher.fetch_tile_name(block); break;
case 1:
if(!(block & 3)) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
} else {
constexpr int sprite = (8 + ((block >> 2) * 3) + ((block & 3) - 1)) << 1;
fetcher.posit_sprite(sprite);
@@ -555,7 +555,7 @@ struct SMSSequencer {
}
if(cycle >= 153 && cycle < 157) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
}
if(cycle == 157) {
@@ -566,7 +566,7 @@ struct SMSSequencer {
}
if(cycle >= 169) {
- fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::Grauw>(cycle));
+ fetcher.base->do_external_slot(to_internal<personality, Clock::TMSMemoryWindow, Clock::FromStartOfSync>(cycle));
}
}
diff --git a/Components/9918/Implementation/LineLayout.hpp b/Components/9918/Implementation/LineLayout.hpp
index c8509b505..460ee9d70 100644
--- a/Components/9918/Implementation/LineLayout.hpp
+++ b/Components/9918/Implementation/LineLayout.hpp
@@ -30,6 +30,7 @@ template <Personality personality, typename Enable = void> struct LineLayout;
// * text mode on all VDPs adjusts border width.
template <Personality personality> struct LineLayout<personality, std::enable_if_t<is_classic_vdp(personality)>> {
+ constexpr static int StartOfSync = 0;
constexpr static int EndOfSync = 26;
constexpr static int StartOfColourBurst = 29;
constexpr static int EndOfColourBurst = 43;
@@ -47,14 +48,13 @@ template <Personality personality> struct LineLayout<personality, std::enable_if
// and falls into the collection gap between the final sprite
// graphics and the initial tiles or pixels.
- constexpr static int LocationOfGrauwZero = 0;
-
/// The number of internal cycles that must elapse between a request to read or write and
/// it becoming a candidate for action.
constexpr static int VRAMAccessDelay = 6;
};
template <Personality personality> struct LineLayout<personality, std::enable_if_t<is_yamaha_vdp(personality)>> {
+ constexpr static int StartOfSync = 0;
constexpr static int EndOfSync = 100;
constexpr static int StartOfColourBurst = 113;
constexpr static int EndOfColourBurst = 167;
@@ -70,8 +70,6 @@ template <Personality personality> struct LineLayout<personality, std::enable_if
constexpr static int ModeLatchCycle = 144;
- constexpr static int LocationOfGrauwZero = 0;
-
/// The number of internal cycles that must elapse between a request to read or write and
/// it becoming a candidate for action.
constexpr static int VRAMAccessDelay = 16;
diff --git a/Components/9918/Implementation/Storage.hpp b/Components/9918/Implementation/Storage.hpp
index 70a4bcd92..bb3820720 100644
--- a/Components/9918/Implementation/Storage.hpp
+++ b/Components/9918/Implementation/Storage.hpp
@@ -85,9 +85,9 @@ struct YamahaFetcher {
static constexpr std::array<Event, size> events() {
std::array<Event, size> result{};
size_t index = 0;
- for(int c = 0; c < 1368; c++) {
+ for(int c = 0; c < 1368; c++) {
// Specific personality doesn't matter here; both Yamahas use the same internal timing.
- const auto event = GeneratorT::event(from_internal<Personality::V9938, Clock::Grauw>(c));
+ const auto event = GeneratorT::event(from_internal<Personality::V9938, Clock::FromStartOfSync>(c));
if(!event) {
continue;
}