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Space Raider

0.87u3 [Frank Palazzolo]


- Hold down the fire button while resetting the game.


- 0.97u2: Frank Palazzolo fixed Space Raider graphics 100% and cleaned up starfield code and added it to Space Raider, Zero Hour and Red Clash. Added 5th SN76496 (4MHz) sound chip and dipswitches 'Difficulty' and 'High Score Names'.

- 12th June 2005: Frank Palazzolo - Just a quick note to say that I've got the graphics on Space Raider 100% correct, including the starfield behavior. I've still got a couple things to look at.

- 3rd May 2005: Frank Palazzolo - Well, I found time to make a few more discoveries. The Space Raider boardset is 3 PCB's. Two of them are full size and obviously two halves of the same design. Then, there is a little PCB grafted on top, connected via a 24-pin dip connector, with wires going to the other two boards. I suspected that this board was the starfield generator. Sure enough, if you unplug it and run the board, the stars disappear. Cool - less work for me. Then, I noticed something else. Two chips were missing from the board, and it was labeled with the number 8011, unlike the other boards. Maybe this board is from another game? Searching through the MAME code, there is a comment that Universal game #8011 is Zero Hour. Luckily, a manual and schematics are available for Zero Hour. The starfield board is the same! In Zero Hour, this board provides both color generation and stars. The missing chips in Space Raider disable the color generation part, since that's already on the main board. Anyways, I added preliminary support for the scrolling stars to MAME, and it looks right. I need to measure a few more things to get the timing exact. When I'm done with Space Raider, I'd like to add the stars to the Zero Hour / Red Clash driver, since it's missing there as well.

- 20th April 2005: Frank Palazzolo - Last night I got a bit further. I fixed up the cocktail mode, and decoded all the dipswitches except one. I also found and decoded the bits which control the scroll speed and direction of the starfield. Finally, I found a "hidden" test mode while disassembling some of the code.

- 17th April 2005: Frank Palazzolo - I got my JAMMA cabinet running again, built the Space Raider-to-JAMMA adapter, and got the board up and running over the weekend. This allowed me to fix most of the graphics problems with the driver! (Most notably, the grid is animating properly now, and it's the right color). The only thing that's noticable now is the lack of a background starfield. Without schematics, this will probably take a long time to get right.

- 7th April 2005: Frank Palazzolo - I first worked on this driver last year, after Pierpaolo started it. (It's currently playable, but there are plenty of graphics glitches.) Unfortunately, I was unable to make any further progress without access to the physical hardware. So, now I have the Space Raider board on my workbench, and I'm slowly making progress. It's amazing what one person can do with a multimeter, some databooks and time. Right now I'm concentrating on the I/O section for the sound cpu. In case anyone's interested, this is how I'm proceeding. First, I found the 5 sound chips and backtraced them to the address decoder for all the IO ports. Now I'm going through ports 0x28-0x2f, 0x30, and 0x38 and figuring out which bits are being used and for what purpose. Ports 0x30 and 0x38 go to a bank of 8 4051 analog mux IC's. They each have graduated resistor ladders connected to them. Maybe they are a fancy volume control or an analog filter. I should be able to get that figured out soon.

- 0.87u3: Frank Palazzolo added Space Raider.

- 25th April 2004: Pierpaolo Prazzoli added Space Raider to the Lady Bug driver but it's far from complete.

Category: Space Shooter 2

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Romset: 69 kb / 14 files / 27.2 zip