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author Curt Coder <curtcoder@mail.com>2019-05-10 17:06:33 +0300
committer Curt Coder <curtcoder@mail.com>2019-05-10 17:06:33 +0300
commitda5950d9448d9d251133187521c6f142c3d81ac4 (patch)
treecab966f89748b9ac1cd8034f5dac63b72a0b967e
parentbd1f2dbac77931b93c51f6d13537fdb432fb51e8 (diff)
cosmac: Fixed long branch instruction timing. [Curt Coder]
-rw-r--r--src/devices/cpu/cosmac/cosmac.cpp2
-rw-r--r--src/devices/video/cdp1861.cpp7
2 files changed, 0 insertions, 9 deletions
diff --git a/src/devices/cpu/cosmac/cosmac.cpp b/src/devices/cpu/cosmac/cosmac.cpp
index e4155a514c7..6398be4f64e 100644
--- a/src/devices/cpu/cosmac/cosmac.cpp
+++ b/src/devices/cpu/cosmac/cosmac.cpp
@@ -1215,8 +1215,6 @@ void cosmac_device::long_branch(int taken)
// S1#1, S1#2
R[P]++;
}
-
- m_icount -= CLOCKS_EXECUTE;
}
void cosmac_device::lbr() { long_branch(1); }
diff --git a/src/devices/video/cdp1861.cpp b/src/devices/video/cdp1861.cpp
index ca6f3173bf3..27f8d0e3729 100644
--- a/src/devices/video/cdp1861.cpp
+++ b/src/devices/video/cdp1861.cpp
@@ -34,12 +34,6 @@ Timing as it applies to the Studio II:
- At the end, the random number seed (not part of video drawing) gets
updated and the interrupt routine ends.
-The current situation:
-- For whatever reason, the CPU is taking 32 cycles to process the 14
- pre-DMA instructions instead of the required 29 cycles. Therefore
- the DMA timer is adjusted to fire 32*8 clocks after INT (every cycle
- is 8 clocks).
-
**********************************************************************/
#include "emu.h"
@@ -175,7 +169,6 @@ void cdp1861_device::device_timer(emu_timer &timer, device_timer_id id, int para
}
m_int_timer->adjust(screen().time_until_pos( SCANLINE_INT_END, 0));
- m_dma_timer->adjust(clocks_to_attotime(32*8)); // adjust DMA to occur exact number of cycle after INT - should be 29*8
}
else
{