Today's release for the Analogue Pocket and MiSTerFPGA platforms is the next entry on the DECO-16 platform. The Cliffhanger: Edward Randy, known in Japan as Edward Randy, is a side-scrolling cinematic action game built on Data East's 16-bit custom hardware.
Kuhga / Vapor Trail (1989)Crude Buster / Two Crude (1990)Dark Seal / Gate of Doom (1990)The Cliffhanger: Edward Randy (1990)Super Burger Time (1990)Death Brade / Mutant Fighter (1991)Tatakae Genshijin: Joe & Mac / Caveman Ninja (1991)Robocop 2 (1991)Thunder Zone / Desert Assault (1991)Wolf Fang: Kuhga 2001 / Rohga (1991)Tumble Pop (1991)Dark Seal II / Wizard Fire (1992)Funky Jet (1992)Gun Ball / Nitro Ball (1992)Diet Go Go (1992)The Great Ragtime Show / Boogie Wings (1992)
Edward Randy is the most involved DECO-16 board brought up so far. It is the first to run the DECO 146 protection device, the first to drive a pair of DECO 55 tilemap generators alongside a DECO 52 sprite engine in a six-layer configuration, and the first to hand its interrupts to a programmable DECO controller rather than a fixed vertical-blank line. Standing it up meant building the protection hardware from the ground up and getting the full graphics path frame-accurate against the original board.
This post covers a technical overview of Edward Randy on DECO-16, the protection and graphics work the board required, and the game itself.
Licensing:
The Cliffhanger: Edward Randy is distributed through the Coin-Op Collection licensing portal, which serves both MiSTerFPGA and Pocket from the same dashboard.
Pocket patrons need to register their device and generate a key before launching the core. Step-by-step instructions and the FAQ are available on the Help page. More information can be found by clicking here and here.
Overview:
Edward Randy runs on Data East's DECO-16 hardware (PCB DE-0347-1), driven by a Motorola MC68000 (DECO Custom 59) at 12 MHz with no second processor on the main bus. The sound system uses a HuC6280 (DECO Custom 45) at 4.0275 MHz, paired with the same audio lineup as Vapor Trail: a YM2203 (OPN) at 4.0275 MHz for FM and PSG, a YM2151 (OPM) at 3.58 MHz for additional FM synthesis, and two OKI M6295 ADPCM samplers, one at 1.007 MHz and the other at 2.014 MHz with bank-switched sample ROM. Audio output is mono.
The video system outputs 256x240 at 58.239 Hz. Graphics are rendered by three Data East custom ICs: a pair of DECO 55 tilemap generators drive four playfields between them, and a DECO 52 handles sprites at 16x16 with multi-width and multi-height support. The two tile chips are configured differently, the first drawing both 8x8 characters and 16x16 tiles from separate ROM banks while the second draws 16x16 tiles only, which gives the board four playfields and a sprite layer composited through software priority. The palette holds 2048 entries in 24-bit RGB, eight bits per channel, split across two RAM banks.
A DECO 66 device sits between the CPU and its inputs, handling the board's protection and I/O. Layer priority and the board's interrupts are both driven by programmable registers rather than fixed hardware. The protection and graphics work this board required is covered below.
Development Challenges:
Edward Randy is the most involved board on the DECO-16 platform to date, and two pieces of it carried the bulk of the work: the DECO 66 protection device and the graphics path.
The DECO 66 is a combined protection and I/O chip. Rather than wiring the controls, coins, and dip switches straight to the CPU, the board routes all of them through the DECO 66, which the game reads back through a scrambled address space. The chip holds two banks of internal RAM that the program writes to and reads back through a 1024-entry address table, with the returned data passed through nibble reordering, XOR, and mask stages before it reaches the CPU. Reading from one specific address switches the active RAM bank, and the sound command latch is driven from inside the chip rather than by a direct write.
Anything that touches the protection path, the inputs, the dip switches, the sound handshake, has to pass through the DECO 66 exactly the way the hardware does, or the game refuses to run. Standing up Edward Randy meant implementing the DECO 66 from the ground up, including the address table, the bank switching, and the read-data transforms.
The same device is used in different configurations across the wider Data East library, with the lower address lines scrambled differently from board to board. The implementation is built to cover those variants, so the work done for Edward Randy applies directly to the Data East boards that follow.
The graphics path was the other half of the effort. Edward Randy composites six layers: four tile playfields and two sprite layers. Two DECO 55 tilemap generators handle the playfields, but they are wired differently from each other. The first reads both an 8x8 character layer and a 16x16 tile layer from separate ROM banks and is the source of the screen flip, while the second drives 16x16 tiles only. The DECO 52 sprite engine draws on top, with 16x16 sprites that support multiple heights, double width, per-sprite flip, and a flash attribute, pulled from a DMA buffer once per frame.
What makes the compositing involved is that the sprites are not a single layer on top. Each sprite carries priority bits that place it either above or below the middle playfields, so the final image interleaves the sprite output through the tile layers rather than stacking them flat. The draw order runs from the opaque background playfield up through the low priority sprites, the foreground playfields, the high priority sprites, and finally the topmost character layer. All of this priority is set by software registers on this board, with no priority PROM involved.
Getting the playfields correct came down to the scroll handling. Each DECO 55 supports per-scanline rowscroll and per-column colscroll, and Edward Randy uses both at once in places, which means the column scroll offset has to be recomputed as the renderer walks across each scanline. The full graphics path was verified frame by frame against the original board until the output matched.
Two smaller pieces rounded out the board. The interrupts are handled by a programmable DECO controller that generates raster interrupts partway down the frame and the vertical-blank interrupt, rather than the single fixed vertical-blank line used on the earlier DECO-16 boards. The HuC6280 sound CPU also runs at 4.0275 MHz here, a different clock from the other DECO-16 boards, and the audio section is the same YM2203, YM2151, and pair of OKI samplers carried over from Vapor Trail.
Core Options:
The MiSTer core includes video settings for aspect ratio, vertical scaling and cropping, scandoubler effects, and H/V positioning and sync adjustments.
Audio settings provide separate OPN FM, OPN PSG, OPM, and two M6295 PCM toggles, each with its own volume control, covering the full sound section. Arcade dip switches are directly accessible from the OSD. Game settings include per-player auto-fire with adjustable rates, mapping options for Player 1 and Player 2, and a synced mapping mode that mirrors Player 1's layout to Player 2.
Cheats are accessible from the OSD and include a starting stage select for any of the seven stages, infinite credits, and per-player infinite energy and invincibility.
The Pocket core provides auto-fire with per-button targeting and adjustable rates. Its cheat set is a single-player-focused subset: starting stage, infinite credits, infinite energy, and invincibility. Arcade dip switches available on Pocket are Player's Power, Game Difficulty, Continue Mode, and Attract Mode Sound.
Known Issues:
The ending theme has a hung note on the YM2151 (IKA-OPM). This does not happen on hardware, I've checked my board and also had another supporter check his Japanese Revision. This will require further investigation as the only component not stood up for DECO-16's audio path in-house is IKA-OPM.
History, Gameplay, and Regional Information:
The Cliffhanger: Edward Randy was developed and published by Data East, reaching arcades overseas in November 1990 and Japan in early 1991. It was led by planner Hiroshi Nakamura under project leader Shigeru Sano, with Hidemi Hamada and Shinji Hirao programming and a large art team handling the pixel work. The soundtrack came from Data East's in-house sound team, Gamadelic, with Akira Takemoto on music and Hiroaki Yoshida on sound effects. Nakamura had originally wanted to make a shooter, but Data East already had one in production, so the project became an experimental action game built around an Indiana Jones-style hero. It spent about a year in development and barely made its deadline, on hardware Nakamura described as carrying five times the memory of Data East's previous boards.
Set in 1930s Europe, the story follows Edward Randy, a young man whose date with his girlfriend Jennifer is interrupted when a girl named Charlotte takes refuge at his home. Charlotte is the granddaughter of a scientist who has stolen a prism stone after learning he was being used to build a doomsday weapon, and she is pursued by the army of a general known as Dark Ogre who needs the prism to finish it. Randy is pulled into the chase, and the game spends its seven stages throwing him through one set-piece after another, a boat chase, a speeding train, a canyon car chase against tanks and a bulldozer, a half-built tower, a giant moving statue, and a final battle leaping between biplanes.
The presentation is the game's signature. It opens in the middle of the action with no title sequence, leans openly on adventure films like Indiana Jones and the Lupin III anime, and keeps the camera moving through scaling and foreground effects to sell the cinematic feel. That direction is what stood out most to players at the time.
The gameplay is built around Edward's whip. An eight-way joystick aims it in any of eight directions, and a two-button layout covers attack and jump, with a sliding move, a dash, and a spin attack that hooks the whip onto objects in the scene and swings him around them while invulnerable. There are no spare lives; instead Edward's health and his score are the same number, climbing as he defeats enemies and dropping when he takes hits, across a single seven-stage run with two-player co-op.
Edward Randy earned a strong reception. Computer and Video Games scored it 82%, and it placed across several categories of the fifth Gamest readers' awards, taking sixth for the grand prize, third for Best Action, second for Best Direction, and ninth for Best VGM. Data East reported roughly four thousand cabinets sold worldwide, split evenly between Japan and overseas.
Updates:
The next entries for the DECO-16 platform will be Crude Buster, Dark Seal, and Diet Go Go. Once those games are released, we will see RoboCop 2, Wolf Fang, and Boogie Wings. The protection work done for Edward Randy is not specific to this board. The same device is used across a number of other Data East titles, so implementing it here clears the way for those releases to follow.
Disclaimer: All product names, trademarks, and registered trademarks mentioned are the property of their respective owners. "Analogue", "Analogue Pocket", "MiSTer", "MiSTerFPGA", "OpenFPGA", "Data East", "NEC", "Hudson Soft", "Motorola", "Yamaha", "OKI", "Indiana Jones", "Lucasfilm", "Lupin III", "TMS Entertainment", and all derivative works are trademarks, registered trademarks, or copyrighted materials of their respective holders. Use of these names does not imply endorsement or association with this post. All rights reserved to their respective owners. This post is for educational and research purposes only.