0.136u1 [Tormod, Team Europe, Smitdogg, The Dumping Union]
TODO:
* Colors (Space Invaders CV)
Bugs:
- Refrence PCB, Screen and Document Photos. Smitdogg (ID 03794)
WIP:
- 0.147u4: Robbbert fixed Player 2 controls in Vortex. Removed 3x 'Unknown' dipswitches.
- 0.138u2: Lord Nightmare and The Dumping Union fixed Vortex - Game now playable. Added partial decrypt function for Vortex (0x0000-0x1FFF is decrypted properly, 0x4000-0x5FFF is probably not), still much work to be done especially regarding memory maps (which are affected by the epoxy block address inverts as well). Replaced dipswitches with 'Coinage' and 7x 'Unknown'.
- 10th June 2010: Smitdogg - Work is underway for the color emulation in Vortex but is not yet complete. Vortex, by the way, was determined to have been developed by Chris Stamper, the founder of Rare.
- 1st June 2010: Smitdogg - Almost complete now besides colors.
- 1st June 2010: Lord Nightmare - With some truly grotesque hacking of Midway 8080 driver i can get ingame in Vortex, with some sound. Dipswitches need figuring out, and the I/O map needs some TLC: Port 0x7 seems to be some sort of select for the functions of ports 0 and 2 (this appears to include dipswitches and possibly lights), port 0 is ? (possibly controlled by port 7), port 1 is out: discrete sound (used for shot sound and explosions), port 2 is out:?lights or shifter (has 0xAA written to it at times) in: ?dipswitches?, port 3 is inputs coins/start2/start1/fire1/ship-rotation, possibly also shifter read?, port 4 is unknown (possibly related to either screen color or the mb14241 shifter), port 5 ?, port 6 ? (has 0 written to it at startup, possibly shifter related) and port 7 is weird: it always has at most one bit written to it set, usually 0x01,0x02,0x04,0x08 or 0x10,0x20; it probably selects the function or destination of something. The game does not appear to have a functional watchdog. The current hack-driver is still using the Midway 8080 driver (old b&w 'invaders' hardware) instead of 8080bw driver (newer space invaders 'invadpt2' hardware with color overlay board).
- 30th May 2010: Lord Nightmare - As Smitdogg posted, David H. figured out how the encryption works on the 0x4000-0x5fff area (it seems to be the same as the 0x0000-0x2fff area, strangely, despite the schematic implying it isn't.). The game now starts, but quickly resets itself over and over due to the watchdog. Some I/O issues remain (perhaps A0 is inverted on I/O as well as on the roms, or perhaps there's some multiplexing going on). In addition, some sort of bizarre hackery using part of vram as the colortable has been performed on the PCB (the normal space invaders part II PCB has a built in color overlay circuit to colorize the display from a fixed rom; on vortex, this comes from ram instead somehow). This has not been figured out either.
- 26th May 2010: Lord Nightmare - Chips have been plausibly identified as a 7486 quad xor and a 7442 1-of-10 inverting decoder/demultiplexer. Working on testing rom descramble. EDIT: The address scramble method used was devious, since it affects ALL I/O from the 8080 in addition to scrambling the roms; this necessitates a new memory map and I/O map. But the worse problem is that the rom data, even when address descrambled, is not valid; there may be additional address and data scrambles wired into the board outside of the epoxy brick. More work is needed, though now it should be fairly easy to build a replacement for the epoxy brick on the board we have. EDIT2: On the other hand, the data might be perfectly valid, and my descrambler code might be COMPLETELY broken, both of which turned out to be the case. The address issue remains, though; the game starts to display but then resets itself repeatedly. Need to fix the memory maps.
- 26th May 2010: Smitdogg - Vortex Revisited: I unearthed Vortex's epoxy block today. Here are pics. It appears that a rom or ram was just glued on top of a CPU. Weirdest thing I've ever seen on a PCB (no, I didn't rip the legs off). Lord Nightmare says this about it: "It's an early form of technology recycling! It's a stone dead or otherwise useless chip which was used as a spacer to hold the rest of the board to be potted in place inside the potting shell. That explains the chopped off legs, which would have only got in the way." I haven't identified the chips yet. We think they are either PALs or proms. Update (Lord Nightmare): R. Belmont had an even better idea, they could have used anything for a spacer, but they chose to use a chip so it would look much more complex than it actually was if you X-rayed the module.
- 0.136u1: Tormod, Team Europe, Smitdogg and The Dumping Union added Vortex (Zilec Electronics Ltd. 1980). Runs on a Space Invaders Part II boardset with an epoxy module in place of the 8080 CPU.
- 22nd December 2009: Smitdogg - I just dumped it yesterday so of course it isn't on MAWS yet.
- 21st December 2009: Smitdogg - I got a super rare "raster Asteroids" style game made by Zilec running on modified Space Invaders hardware. Credits so far: Tormod, Team Europe, Smitdogg and The Dumping Union.
LEVELS: 1 (endless)
Recommended Games (Asteroids):
Blasto
Asteroids
Asteroids Deluxe
Dai San Wakusei Meteor
Astropal
Space Duel
Space Force
Star Trek (Head On hardware)
Vortex
Moon Shuttle
Moon War
Space Fortress
Space Fury
Sinistar
Zektor
Mad Planets
Blasteroids
Space Lords
