WillFA11 - Lethal Weapon 3 speed test, round 2 - results
Test build v1.27
=====================================================================

Thanks a lot for the four clips and the notes - the tripod made them
easy to measure, and the diagnostics switch is confirmed fixed.


YOU WERE RIGHT: ALL FOUR SETTINGS ARE TOO SLOW

We measured how long each high score entry stays on the display,
frame by frame, exactly like in your original MPU clip:

    Setting            time per entry    compared to original
    ----------------   ---------------   --------------------
    original MPU           2.33 s
    D                      2.49 s             7 % slower
    A                      2.90 s            24 % slower
    B                      3.18 s            36 % slower
    C                      3.51 s            50 % slower

So "everything looks slow" is a correct observation. Our estimate came
from our test board, which has no DMD connected. Lethal Weapon 3 sends
the DMD data inside its interrupt routine, so with a real DMD the CPU
has less time left for the rest of the game, and the right setting is
faster than we calculated. The four measurements fit our model very
well, so we now know the right value much more precisely.


A SECOND FINDING: THE CPU CLOCK

While checking this we found that since an older WillFA11 version the
CPU clock has been about 12 % lower than on the original board
(0.893 MHz instead of 1 MHz). Everything the game times by its
interrupt - lamp shows, timers, the DMD data rate, sound timing - has
been running 12 % slow in every setting. This adds to the slow feeling.

The new build v1.28 fixes the clock and uses settings around the newly
calculated value (see below).


SOME QUESTIONS

1. DMD "reset"
   The game resets the DMD board by itself when the DMD does not
   answer for about half a second. That is most likely what you saw.
     - Did it happen during a game or also in attract mode?
     - In which setting(s)?
     - What does the DMD show - the start-up screen
       "LETHAL WEAPON R2.0 8/14/1992", or just a blank/restart of the
       animation?
     - Have you ever seen this with your original MPU?

2. The "wiieeew" sound
   There is none in the four clips. When does it happen - during a
   game, at the same moment as the DMD reset, in a certain setting?
   If you manage to catch it on video, that would help a lot.

3. v1.28 has a setting with all speed DIPs OFF (setting D). The game
   runs much too fast there, that is expected. Does the DMD reset or
   the sound still happen in that setting? That tells us whether they
   are related to the speed at all.


PIN2DMD

Thanks for the details: with WillFA11 the PIN2DMD stays on its boot
screen and shows nothing, with your original MPU it works, and it is
connected in place of the original display. That is on our list, we
are looking into it.


WHAT COMES NEXT

Attached is test build v1.28 (WillFA11_v128_calib.jic) with the
corrected clock and three settings around the new target, plus the
instructions in LW3_speed_test_v128.txt - the same kind of clip as
last time. With the numbers from your clips we expect this to be the
last speed round.

Thanks again for your patience and the excellent clips!