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tms9918: widen vcounter to 9 bits #113

Merged
merged 1 commit into from Aug 27, 2021
Merged

tms9918: widen vcounter to 9 bits #113

merged 1 commit into from Aug 27, 2021

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invertego
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By using an 8 bit counter, the last 6 lines of every frame were being
skipped and the VDP was firing vblank interrupts ~2.3% faster than
intended in the ColecoVision, SG-1000, and MSX.

This also fixes the corrupted turtle graphics in Frogger for
ColecoVision, though this is mostly by chance. The game is buggy and
susceptible to graphics corruption if a vblank is raised between these
instructions:

1d09 out ($bf),a ; write low VRAM address byte
1d0b ld a,h
1d0c out ($bf),a ; write high VRAM address byte

It could easily be regressed by any future change that impacts timing.

@invertego
tms9918: widen vcounter to 9 bits
aa5ce28 
By using an 8 bit counter, the last 6 lines of every frame were being
skipped and the VDP was firing vblank interrupts ~2.3% faster than
intended in the ColecoVision, SG-1000, and MSX.

This also fixes the corrupted turtle graphics in Frogger for
ColecoVision, though this is mostly by chance. The game is buggy and
susceptible to graphics corruption if a vblank is raised between these
instructions:

1d09  out  ($bf),a      ; write low VRAM address byte
1d0b  ld   a,h
1d0c  out  ($bf),a      ; write high VRAM address byte

It could easily be regressed by any future change that impacts timing.
@LukeUsher LukeUsher merged commit b2e6f2b into ares-emulator:master Aug 27, 2021
@invertego
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This fixes #84, though for the reasons given in the commit message, it won't be surprising if it comes back in the future.

@LukeUsher LukeUsher mentioned this pull request Aug 27, 2021
Closed
@invertego invertego deleted the tms9918_vcounter branch September 27, 2021 16:19
invertego added a commit to invertego/ares that referenced this pull request May 4, 2022
@invertego
Squashed 'thirdparty/sljit/' changes from d6a0fa61e..7f08de6ff
28ea480 
7f08de6ff Improve jump code generator on MIPS
469c61db9 Improve mips code generator
a4e8e34ef Support unsaved registers on s390x
f404f3608 Support unsaved registers
88d4778b9 Add license file
160b6f99d windows: fix building in arm64 with clang (ares-emulator#126)
022482eeb wxexec: officially drop support for EOL NetBSD < 8 versions (ares-emulator#124)
beda74f07 Support reworked floating point compare on s390x
050215b22 Remove unnecessary checks
6b950049d Improve floating point compare.
6ace72c90 windows: allow building with MinGW64 gcc/clang (ares-emulator#125)
186b07064 mips: avoid sign conversion warnings with clang (ares-emulator#122)
e0b17f5a6 macos: fix recent regression breaking build in macos/arm64e (ares-emulator#121)
68d9b4bac misc: mostly to avoid warnings (ares-emulator#120)
76330309a Update s390x.
6807c7a8f Remove SLJIT_NEG.
ca530a4a7 Readd carry flag support.
5f60134b5 s390x: be explicit about cache coherence needs (ares-emulator#119)
75a555604 power: avoid bogus clear_cache builtin in gcc >= 10 (ares-emulator#118)
1448ef97c sparc: avoid NOP implementation for clear_cache with gcc (ares-emulator#117)
ad69ad87b sparc: build fixes (ares-emulator#116)
47646b943 Support incoming arguments in scratch registers for s390x.
4fbdd6953 Support incoming arguments in scratch registers.
86ebfbd50 Rework x86-32 function prologue/epilogue.
2f8cf7a08 Increase the number of floating point registers on ppc, mips, and sparc.
2737606ee Increase the number floating point registers on s390x.
03469c8e1 Rename tail call to call return and minor ARM improvements.
7cb8a5c24 Increase the number floating point registers on x86 and ARM.
b35ab5e7e Implement fpu support on s390x.
dcc8fc149 misc: fix -Wextra related errors (ares-emulator#114)
92fcb0fe5 Fix fallthrough errors.
d345a64b3 misc: build/documentation fixes from recent changes (ares-emulator#113)
ff6ec4f74 Implement tail call on MIPS.
eed28632f Implement tail call on ARM.
d7793570f Reduce signed comparison warnings.
30b2dcd83 Reduce value conversion warnings on s390x.
c783c1119 Reduce value conversion warnings on MIPS, PPC, SPARC.
335ee51f5 Reduce value conversion warnings on ARM.
8d0f668fa Improve value conversion warnings.
373163144 Implementing tail calls for x86.
9c8b6961b Improve argument sanity checks.
24c547b7e Swap f32 and f64 argument types.
7f0afb25e Rework function argument list descriptor macros.
585ac42bf Implement four argument support for emit enter.
b5e0b1234 Improve mov32 operation.
433294658 Fix incorrect function call (ares-emulator#112)
cf594d74d Change SLJIT_I32_OP and SLJIT_F32_OP to SLJIT_32.
ae5fff841 Improve arm code generator.
43538b877 Replace SLJIT_UNUSED with appropriate function calls.

git-subtree-dir: thirdparty/sljit
git-subtree-split: 7f08de6ff5a86a4eaa53e33a16136f790e16c709
LukeUsher added a commit that referenced this pull request May 13, 2022
@LukeUsher
Squashed 'thirdparty/sljit/' changes from d6a0fa61e..761d48d2b
1d26512 
761d48d2b Improve constant generation
1f32a9f23 Implement fpu operations for RISC-V
ad99f17a9 Improve x86 float compare
fb55788d0 Initial implementation of RISC-V port
7f08de6ff Improve jump code generator on MIPS
469c61db9 Improve mips code generator
a4e8e34ef Support unsaved registers on s390x
f404f3608 Support unsaved registers
88d4778b9 Add license file
160b6f99d windows: fix building in arm64 with clang (#126)
022482eeb wxexec: officially drop support for EOL NetBSD < 8 versions (#124)
beda74f07 Support reworked floating point compare on s390x
050215b22 Remove unnecessary checks
6b950049d Improve floating point compare.
6ace72c90 windows: allow building with MinGW64 gcc/clang (#125)
186b07064 mips: avoid sign conversion warnings with clang (#122)
e0b17f5a6 macos: fix recent regression breaking build in macos/arm64e (#121)
68d9b4bac misc: mostly to avoid warnings (#120)
76330309a Update s390x.
6807c7a8f Remove SLJIT_NEG.
ca530a4a7 Readd carry flag support.
5f60134b5 s390x: be explicit about cache coherence needs (#119)
75a555604 power: avoid bogus clear_cache builtin in gcc >= 10 (#118)
1448ef97c sparc: avoid NOP implementation for clear_cache with gcc (#117)
ad69ad87b sparc: build fixes (#116)
47646b943 Support incoming arguments in scratch registers for s390x.
4fbdd6953 Support incoming arguments in scratch registers.
86ebfbd50 Rework x86-32 function prologue/epilogue.
2f8cf7a08 Increase the number of floating point registers on ppc, mips, and sparc.
2737606ee Increase the number floating point registers on s390x.
03469c8e1 Rename tail call to call return and minor ARM improvements.
7cb8a5c24 Increase the number floating point registers on x86 and ARM.
b35ab5e7e Implement fpu support on s390x.
dcc8fc149 misc: fix -Wextra related errors (#114)
92fcb0fe5 Fix fallthrough errors.
d345a64b3 misc: build/documentation fixes from recent changes (#113)
ff6ec4f74 Implement tail call on MIPS.
eed28632f Implement tail call on ARM.
d7793570f Reduce signed comparison warnings.
30b2dcd83 Reduce value conversion warnings on s390x.
c783c1119 Reduce value conversion warnings on MIPS, PPC, SPARC.
335ee51f5 Reduce value conversion warnings on ARM.
8d0f668fa Improve value conversion warnings.
373163144 Implementing tail calls for x86.
9c8b6961b Improve argument sanity checks.
24c547b7e Swap f32 and f64 argument types.
7f0afb25e Rework function argument list descriptor macros.
585ac42bf Implement four argument support for emit enter.
b5e0b1234 Improve mov32 operation.
433294658 Fix incorrect function call (#112)
cf594d74d Change SLJIT_I32_OP and SLJIT_F32_OP to SLJIT_32.
ae5fff841 Improve arm code generator.
43538b877 Replace SLJIT_UNUSED with appropriate function calls.

git-subtree-dir: thirdparty/sljit
git-subtree-split: 761d48d2b89a048badbd9c5cf45da75336891cfe
LukeUsher added a commit that referenced this pull request Feb 17, 2024
@LukeUsher
Squashed 'thirdparty/libchdr/' changes from 2648c221c9..2a1119c686
8066a46 
2a1119c686 Merge pull request #113 from scribam/ci-switch-vita
51bd8e9696 Add GitHub Actions for Switch and Vita
bd19fbd6fc Merge pull request #110 from scribam/zlib-1.3
577f3276c9 Merge pull request #111 from scribam/c90
5f04e2fdf9 Merge pull request #109 from scribam/actions-checkout
16ebde42b8 Merge pull request #112 from scribam/dr_libs
647f42b274 dr_flac: Version 0.12.42
5fd5165194 Compilation fix when using C90 with GCC
ea2da72d3d Bump zlib to 1.3.1
4e0aa45a78 Update actions/checkout to v4

git-subtree-dir: thirdparty/libchdr
git-subtree-split: 2a1119c686eb07033d02f8c6d12406f8fd373775
LukeUsher added a commit that referenced this pull request Feb 25, 2024
@LukeUsher
Squashed 'thirdparty/libchdr/' changes from 2648c221c..2a1119c68
b4399c5 
2a1119c68 Merge pull request #113 from scribam/ci-switch-vita
51bd8e969 Add GitHub Actions for Switch and Vita
bd19fbd6f Merge pull request #110 from scribam/zlib-1.3
577f3276c Merge pull request #111 from scribam/c90
5f04e2fdf Merge pull request #109 from scribam/actions-checkout
16ebde42b Merge pull request #112 from scribam/dr_libs
647f42b27 dr_flac: Version 0.12.42
5fd516519 Compilation fix when using C90 with GCC
ea2da72d3 Bump zlib to 1.3.1
4e0aa45a7 Update actions/checkout to v4

git-subtree-dir: thirdparty/libchdr
git-subtree-split: 2a1119c686eb07033d02f8c6d12406f8fd373775
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2 participants
@invertego @LukeUsher