summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/video/starfield_05xx.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/mame/video/starfield_05xx.cpp')
-rw-r--r--src/mame/video/starfield_05xx.cpp10
1 files changed, 10 insertions, 0 deletions
diff --git a/src/mame/video/starfield_05xx.cpp b/src/mame/video/starfield_05xx.cpp
index 23c349eae33..8a0ec025256 100644
--- a/src/mame/video/starfield_05xx.cpp
+++ b/src/mame/video/starfield_05xx.cpp
@@ -288,6 +288,16 @@
the Fibonacci form, which is why the latter is used in this
implementation.
+ The LFSR used by Wolfgang and Jindřich had taps at 15, 12, 10 and 5.
+ With the same seed values, the following holds true:
+
+ Decode_W(lfsr[t-4]) = Decode_J(lfsr[t])
+
+ The two decoding algorithm (Wolfgang, Jindřich) thus delivered the
+ same results but with a 4 clock difference.
+
+ Jindřich: Seed Value 0x70cc
+ Wolfgang: Seed Value 0xe7bf
---------------------------------------------------------------------------