EXOLON.ROM doesn't work

svofski / vector06cc

Вектор-06ц в ПЛИС / Vector-06c in FPGA

http://svofski.github.io/vector06cc/

Other

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EXOLON.ROM doesn't work #3

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago

EXOLON would show title screen, play music but will not accept keyboard
input for starting the game. Also, border would flicker.

Earlier versions flickered the border as well but keyboard was ok. This can
be the timing issue related to the exact moment when retrace IRQ signal is
generated. However, this moment is verified with M@COLOR demo and should be
quite precise.

Original issue reported on code.google.com by svof...@gmail.com on 17 Dec 2007 at 8:41

GoogleCodeExporter commented 9 years ago

It is possible, albeit very improbable, that some of the instructions still have
different timing. This program has to be debugged and analyzed.

Original comment by svof...@gmail.com on 18 Dec 2007 at 2:59

GoogleCodeExporter commented 9 years ago

This is actually a N/R. Could be different ROM versions?

Original comment by svof...@gmail.com on 13 Jan 2008 at 2:01

Changed state: Verified

GoogleCodeExporter commented 9 years ago

After the issue with palette writes has been resolved, it is evident that 
Exolon has
serious problems. The keyboard works, but there are strange things happening 
that
look like out 0c's in large quantities during screen scan. The keyboard works 
though.

Original comment by svof...@gmail.com on 16 Jan 2008 at 11:47

Changed state: Accepted

GoogleCodeExporter commented 9 years ago

; mystery snippet 1: 
; program the counter to divide by 7500h instead of 7530h
; then latch the value with 2 lsb set
; according to the datasheet, 4lsb are don't care when latching
; could it be that it's a mode switch?
mvi a, 74
out 08
xra a
out 0a
mvi a, 75
out 0a
mvi a,43 ;; what does this mean?
out 08

;; mystery snippet 2
;; similar to #1 but here BCD mode is set up at once
;; same value is written to both msb/lsb, then latched 
mvi a, b5
out 08
mvi a, 73
out 09
out 09
mvi a, 83

(ok, snippet 2 is related to sound playback)
out 08
ret
;

Original comment by svof...@gmail.com on 17 Jan 2008 at 10:14

GoogleCodeExporter commented 9 years ago

Frame is 624 lines now, hence 7500h.

Rev.207 fixed.

Original comment by svof...@gmail.com on 17 Jan 2008 at 6:27

Changed state: Verified