The purpose of this site is to document as much information on the little known Space Invaders clone, IPM Invader. For those who are not aware of IPM Invader, it is the game that has a 'coffee break' after every 3 waves of invaders. This has always fascinated me and I enjoyed reaching the 'coffee break' when I was young.
GAME SPECIFICATIONS
2-way joystick
Aspect: 3×4
Resolution: 224×240 (240×224 rotated)
CPU: MOS 6502 @ 2.5 MHz
Colors: 8
* IPM Corp. was renamed Irem Corp. in 1979. MAME lists IPM; most arcade databases list IREM.
CABINET & HARDWARE
Click any image to view at full native resolution.
MANUFACTURER
According to MAME and Arcade Museum sources, Irem was founded in 1974 as IPM Corp. in Hakusan, Japan. The company released IPM Invader during this period and renamed itself Irem Corp. in 1979 (International Rental Electronics Machines). MAME lists the manufacturer as IPM; most modern databases list Irem. The archived MAME Targets page by Randy "Mr Goodwraith" Hoffman documents the same IPM→Irem connection. A Japanese game database (archived) also lists mahjong titles prefixed with "IPM" from 1978, consistent with the pre-rename branding.
Two Japanese sites claim there were IPM Invader Part I, II, III. Whether this is true or not cannot be verified for lack of information. Theories suggest these may have been software revisions or more likely dip switch settings. (Dip switch settings and more will be discussed in detail in the Technical Data section). IPM Invader Part II, III and/or Capsule Invader may have been mistaken for being different games when it was more likely just IPM Invader with the dip switch settings changed.
DATE OF MANUFACTURE
Most databases — including the Arcade Museum and MAME — list 1979 as the release year. Arcade-history notes a January 1979 release. A minority of sources cite 1978; the 1978–79 range reflects development overlap with the original Space Invaders boom rather than a firm second production year.
Reply from John of Arcade 80's (operator, South East Queensland, Australia):
"Basically this board was bought into Australia by a company called Vision Electronics (circa 1979). It is widely known as the 'poor mans' version of Space Invaders. Some 500+ pcbs of this version were bought into the country. While Leisure and Allied were still making big dollars on the Taito version [of Space Invaders] which was strictly licensed to LAI. Vision Electronics found a source through a company called Irem. Irem manufactured a copy pcb. With legal threats from its Japanese counterpart [Taito] the company [Irem] redesigned the original pcb into the 'IPM Invader' version.
IPM Invader hit the Australian playing market about August 1979 and was not as well received to the market as its counterpart. This was due to the Vision Electronics designed cabinets which could not compete with the colourful Taito/LAI cabinets. Also, there was a new game on the market called Galaxian (1979) which delivered bright colours, exciting sounds and unique game play. The Space Invader phenomenon was over! This then lead the way for more exciting games like Pac-man (1980), Frogger (1981) and the all time favourite Galaga (1981)."
I'd hardly call it the 'poor mans' version as it is a great clone of Space Invaders. With added unique features like the 'coffee break' and the capsules make this an extension of an already great game; definitely NOT a poorer version of it.
COLOUR MONITOR
IPM Invader uses a colour monitor, unlike others which were using B&W monitors with colour overlays. Here where it gets a little fuzzy. Some claim that in Irem manufacturing IPM Invaders in 1978-79, that it was the first to make a Space Invader type game with a colour CRT or monitor. It would be in 1980 that Taito came to the table with Space Invaders Part II which had a colour monitor. In addition, according to the Arcade Museum (formerly KLOV), this game [Space Invaders Part II] was released in America by Midway as Space Invaders Deluxe. "Deluxe" used a color overlay however, instead of a color monitor.
According to the Arcade Museum, in 1978 a company called Logitec Co. LTD, manufactured a bootleg Space Invaders (Logitec) with a colour monitor. While most of the screen remains B&W, the green is actually generated by the PCB (Printed Circuit Board) and although it looks very much like an overlay it's not.
Back then this Logitec bootleg PCB, because of its design and minimal memory room on the board (remember we are talking old technology), the game was very complex for its time. It used an Intel 8080 processor which, unlike the later Z80, had its limitations. When this game was first designed it was originally going to be released as a B&W game and not colour. The green is done by taking a segment out of the video processing area of the PCB and pulling it down with a bipolar PROM to generate the effect. There are actually 2 video lines on this pcb — 1 for B&W and the other for sync and colour.
So the question remains who had colour first?
The answer would have to be Logitec Co. LTD, as it is more commonly known to be manufactured in 1978 as opposed to IPM Invaders 1978-79. Until I receive more information on this, it will remain =?
UNIQUE FEATURES
The Coffee Break
The reason that this variation of Space Invaders is unique, is that it has the famous 'coffee break' which no other has. What's the 'coffee break'? The 'coffee break' is a unique feature in IPM Invaders whereas after every 3rd wave or pattern of invaders, the 'coffee break' appears.
Basically, it is a rest in game play from the monotonous and repetitive onslaught from waves of invaders. Much like the challenging stage in Galaga breaks the game up. Or in Pac-man when after the second frame, a short respite is had with Pac-man being chased by the ghost across the screen only to have him grow larger and chase them back across the screen in the opposite direction.
The Capsules
Another unique feature in IPM Invader is the 'capsules'. When dip switch settings are changed to advanced settings, the game becomes more difficult with the introduction of the UFO (mystery score ship) dropping 'capsules' that hatch into new invaders. The 'capsules' cannot be destroyed until they hatch, and are dropped across the screen to defeat the players 'narrow column' strategy. The 'coffee break' picture above shows the UFO dropping 'capsules'.
Capsule Invader is listed by Irem as a separate 1979 title, but Japanese collector sources describe it as an advanced variant of IPM Invader — the same hardware with dip switches set to enable capsule-dropping UFOs. That matches how collectors treat it in practice.
Note: IPM Invader is also a Dual sync game meaning it has separate Horizontal and Vertical outputs, and many have been modified to composite negative Horizontal sync because they won't work on most monitors.
Help Preserve Arcade History
If you have original manuals, schematics, PCB photos, dip switch settings, or stories about IPM Invader from the arcades, please get in touch. Every piece of information helps document this obscure but beloved clone.