After many hours of researching, I found there to be hardly any information on the little known IPM Invader. (In the bibliography and links page I have linked every page I could find).

This site will:

• Provide technical data
• Document it's history
• Attempt to raise the profile of the game.

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Manufacturer
According to MAME Targets web site compiled by Randy "Mr Goodwraith" Hoffman, IPM Invader was manufactured by a company called IPM, which later changed it's name to IREM. No other information I have gathered supports this, but it must be noted that on this japanese site, it list a mahjongg game with IPM in front of it's name, i.e. IPM Mahjongg 1978. Just about all other sites refer IREM as the manufacturer.

Two Japanese sites, (here & here), claim there were IPM Invader Part I,II,III. Whether this is true of 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 '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. (More on this in 'Unique' section).

˜Date of Manufacture

Date of manufacture on most information sites state 1979 as the production date. A minority states that 1978 was the production date while others just put unknown.

Below is a reply from John of Arcade 80's who is an operator in South East Queensland, Australia. Here's what he had to say on the subject:

"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.

IPM Invader users 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 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 KLOV, 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 pirated PCB, because of it's design and minimal memory room on the PCB, (remember we are talking old technology), the game was very complex for it's time. It used an old 8080 processor which unlike the Z80 processor, it 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 affect. 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 apposed to IPM Invaders 1978-79.

Until I receive more information on this, it will remain =?

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. Refer to the picture below for an example.

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.

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 made by the same manufacturer at the same time which indicates that it's just IPM Invader with the dip switches set on advanced difficulty.

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.