From 89e879e806aaff14624d3c19f256fe6cbae72039 Mon Sep 17 00:00:00 2001 From: Roberto Zandona Date: Thu, 31 Jul 2008 10:39:05 +0000 Subject: [PATCH] add infos to the 1943 driver (video) about priorities encoded in PROM --- src/mame/video/1943.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/src/mame/video/1943.c b/src/mame/video/1943.c index dc2f84c8f21..51351b38559 100644 --- a/src/mame/video/1943.c +++ b/src/mame/video/1943.c @@ -1,3 +1,32 @@ +/*************************************************************************** + +1943 Video Hardware + +This board handles tile/tile and tile/sprite priority with a PROM. Its +working is hardcoded in the driver. + +The PROM have address inputs wired as follows: + +A0 bg (SCR) opaque +A1 bit 2 of sprite (OBJ) attribute (guess) +A2 bit 3 of sprite (OBJ) attribute (guess) +A3 sprite (OBJ) opaque +A4 fg (CHAR) opaque +A5 wired to mass +A6 wired to mass +A7 wired to mass + +2 bits of the output selects the active layer, it can be: +(output & 0x03) +0 bg2 (SCR2) +1 bg (SCR) +2 sprite (OBJ) +3 fg (CHAR) + +other 2 bits (output & 0x0c) unknown + +***************************************************************************/ + #include "driver.h" UINT8 *c1943_scrollx;