From c7ec6f82b2a4c7f228622f53066e6d8891d2004e Mon Sep 17 00:00:00 2001 From: Robbbert Date: Thu, 10 Jan 2013 07:48:46 +0000 Subject: [PATCH] Schaser : added newly-discovered information (nw) --- src/mame/drivers/8080bw.c | 37 +++++++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/src/mame/drivers/8080bw.c b/src/mame/drivers/8080bw.c index dfbcb6bf537..da61eca5055 100644 --- a/src/mame/drivers/8080bw.c +++ b/src/mame/drivers/8080bw.c @@ -123,18 +123,31 @@ there at all - Space Chaser (schaser) - 1. Strange bug; sometimes the missile sound continues into the - music/explosion. - 2. If "Hard" mode is selected, numerous bugs appear which - seems to be an emulation fault. Every revision we have - shows the problem, whereas the real hardware works fine. - - You start with 9000 points (instead of 0). - - On the screen where you are awarded your Bonus, you will - instead get (or sometimes lose) a random amount. - - At the end, if you got the High Score, it could be changed - to something else. - All these bugs can be cured by a simple 1-byte patch: - ROM_FILL( 0x47e5, 1, 0xc3), but why is it necessary? + 1. Schematic has SX2 & 4 swapped by mistake. + + 2. Dipswitch 4 we have listed as "Easy/Hard", however the manual says + it should not be used. The Hard position displays many bugs. + + 3. Confirmation of these on a real machine (schaserb set) have been + received from the owner of the PCB. + "Hi Rob, + I seem to get the same bugs as you with Dip4 set to off. Score starts at 9000, + 2 missiles on first level etc.. It makes no mention of dip4 adjusting the hardness + in the manual, are you guys sure that's what it was intended for "in the factory"? + However you were correct in thinking the schematics were wrong. My multimeter found + the following: + 15k resistor - pin 7 + 39k - pin 10 + 82k - pin 12 + It looks like they have Sx2 and Sx4 the wrong way round on a latter page of the schematics." + + 4. The "Hard" mode bug can be fixed with a single byte patch: ROM_FILL( 0x47e5, 1, 0xc3) + + 5. I have seen real machines with Hard mode set, that worked properly, thus there + must be yet another romset still waiting to be found. + + 6. Strange bug; sometimes the missile sound continues into and past the + music/explosion. This didn't happen on the real machines I played. - Space Chaser (schasercv) These cheats exist in this game: