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I recently learned that mid 1980s, Motorola was working on a discrete graphics chipset that would be a great leap forward from its 6847 Video Display Generator and 6845 display controller. It was called the RMS (R.M.S. or Raster Management System) chipset and consisted of the MC68486 and MC68487 ICs.

It (would have) had the following highlights:

  • Horizontal resolution from 64 to 640 pixels
  • Vertical resolution from 64 to 500 pixels
  • 32 available colors from a palette of 4096 (Bit-plane mode)
  • MC6847/MC6883 emulation
  • Directly compatible with MC6809E and MC68000 CPUs
  • ASCII and mosaic characters in internal ROM
  • 6 text modes
  • Text attributes: underline, flash, invert, color, double height and width
  • From 32 to 32K user-definable characters (sprites?)
  • Game-oriented attributes: collision, priority, color offset
  • Large virtual screen with smooth scrolling

Motorola had gotten pretty far with the development of this chipset and extensive documentation was already written and available (RMS Manual 1984). EDIT: I also found some promotional material.

enter image description here

In the book "CoCo: The Colorful History of Tandy’s Underdog Computer" (ref), authors Boisy Pitre and Bill Loguidice describe how the RMS originally was developed in conjunction with or at least at the same time as the Tandy Color Computer 3, which was released in summer 1986. Presumably then, the CoCo3 was developed during 1985-86.

However, the manual for the RMS is dated to spring 1984 implying that the RMS was developed during 1983. It was also known beyond the walls of Tandy and Motorola as documented by several public mentions spanning 1984-1986:

RMS mentioned in Radio Electronics October 1984

However, 1983 was the year of the development and release of the CoCo2 and, incidentally, also the mysterious "Deluxe Color Computer" that never came to fruition. When the CoCo2 was released (and the Deluxe was dropped) some time presumably went by before Tandy started considering the CoCo3.

The Deluxe Color Computer is described in the book by Pitre and Loguidice, as well as his blog Late Night CoCo.

So I have two main questions:

  1. How could the RMS have been developed in conjunction with the CoCo3, if it was developed in the year the CoCo2 was developed?
  2. What other systems has the 68486/68487 been used in, if any, so what was the fate of this early graphics powerhouse?

Thanks in advance for any comments and replies!

EDIT:

I found some more leads. Apparently, according to the RMS brochure, the system was supposedly showcased at the 1984 winter Consumer Electronics Show in Las Vegas. I tried to get more info, and I found some more mentions of this being demonstrated there, like the DataQuest Newsletter. If anyone has more info on whether this actually happened, or was merely planned, but dropped at the last moment, please leave a comment.

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  • I suppose what happened is that they started working on the CoCo3 already during winter 1983/1984, while the RMS was pretty far in development and released within months thereafter.
    – Fedor Alexander Steeman
    May 10, 2019 at 15:54
  • What the heck!? bitplane architecture, 32 color out of a palette of 4096 are pretty, resolution up to 640x500ish seems a description of Amiga's OCS. Maybe the result of a collaboration with Hi-Toro/Amiga before the Commodore acquisition?
    – user180940
    May 11, 2019 at 7:30
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    Well, the precursor to the Amiga chipset, dubbed Lorraine, was developed in 1983 as well, i.e. at the same time, so I doubt there's any connection, unless they were spying on each other. A lot of these features are extensions of the state of the art, so I suppose it's parallel developments. Besides, the only way to get a 32 colour bitmapped display is using bitplanes.
    – Fedor Alexander Steeman
    May 11, 2019 at 19:46
  • @FedorSteeman Not really. 32 colour does not have to mean bitplanes. It's one of many possible ways.
    – Raffzahn
    May 11, 2019 at 23:49
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    @Raffzahn Have you got some examples then, because I couldn't find any? Thirty-two colours implies 5 bits, which is an odd number to use. Graphics chips of this era would consume 8-bit bytes of data at a time, so you would generate pixels as a fraction or whole of that. Unless you're wasting bits, that would be 8-bit (256 colours), 4-bit (16), 2-bit (4) or 1-bit (2). Bit planes are then the only way to combine other numbers of bits into pixels, at least when we're talking bitmap graphics. Color cell or character-based graphics ore sprites are another matter, of course.
    – Fedor Alexander Steeman
    May 12, 2019 at 6:30

2 Answers 2

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Based on the absolute dearth of information on the Motorola 68486/68487 video chipset (RMS), I would conclude that it was never officially released as a product for OEMs, and was therefore never used in any actual computer products.

[UPDATE: Per OP finding, it appears that one company, Micro Concepts of the UK, was offering an SBC based on the 68000/010 with RMS, for sale in 1987. They advertised the product multiple times.]

I would also say, speculatively, that the chipset was likely still under development in 1984. For a new product seeking potential customers, it would not be unusual to produce a manual while the product was still under development. That way, changes and additions could be made to the product to suit customer feedback.

The obvious reason that Motorola would have undertaken this project is that part of their business was creating peripheral controllers that easily interfaced to their microprocessor products. Prior to 1984, Motorola had great success in selling CRT Controllers (6845) for many different machines, including those based on the 6502, Z80, and even the early PC graphics boards. Additionally, they had a successful partnership with Tandy using the 6847 in the CoCo 1/2 and Dragon's clones. By 1983/84, Motorola was likely keen to update this video peripheral hardware to match competitors' capabilities and to make use of more advanced 16-bit processors like their own 68000.

The reason this work never came to fruition is somewhat speculative, but I can see two obvious factors that would have killed the RMS project:

  1. RMS turned out to be unsuitable for use in the CoCo 3. The CoCo 3 was a late 8-bit era system designed to be extremely low-cost, fully compatible with the earlier CoCo's, and competitive with the Commodore C128, Atari XL/XE, and inexpensive Apple clones (Laser 128). As such, Tandy wanted to match or exceed those machines on specs while also undercutting them on price. They succeeded in this with the CoCo 3, but only by using the GIME chip (see photo). Using GIME instead of RMS resulted in a low-cost, single chip, compatible, integrated solution for video and memory, and having specs needed to compete with the aforementioned 8-bit machines.
  2. RMS turned out to be redundant for the 68000. The 68000 was a popular 16-bit microprocessor, but the system integrators who were using it either pursued proprietary solutions that were better than RMS (Amiga, X68000), deemed to be cheaper and good enough (Atari ST), or had different priorities, like crisp monochrome graphics on a small screen (Mac). With the industry heading this way, Motorola would not find many takers for RMS amongst their 68000 customers.

Color Computer 3 motherboard showing GIME

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  • 2
    While this is guesswork, I'd take it as well founded.
    – Raffzahn
    May 11, 2019 at 18:46
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    I agree with @Raffzahn. Solid speculation and interesting to consider! I do have one correction: The GIME was developed by Tandy themselves. Motorola can't take credit for that one! ☺
    – Fedor Alexander Steeman
    May 11, 2019 at 19:41
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    @FedorSteeman Good catch. Added photo of my own machine to show Tandy's copyright stamp on the GIME.
    – Brian H
    May 11, 2019 at 23:13
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    @FedorSteeman I wouldn't try to argue that Motorola didn't produce manuals, marketing materials, and perhaps even product samples for RMS. But I can't find evidence of any actual product using it. So, I doubt the RMS chipset was ever produced or sold in quantity, due to the reasons I proposed.
    – Brian H
    May 12, 2019 at 15:03
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    Yes, it is strange. Perhaps Motorola kept the project alive, in the sense that they still marketed it to their customers in the hopes of landing some big account that would allow them to produce and ship RMS. Only when that did not materialize did it sort of fade slowly from the industry consciousness. If the Amiga and early Macs had been a bigger success, maybe some other big company would have introduced a similarly specced competitor to it using the 68K and RMS to get it to market quickly. I'm sure some at Motorola still had illusions of overthrowing Intel and PC's in 1984-1986.
    – Brian H
    May 13, 2019 at 14:33
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With some Google sorcery, I finally located a system that used the elusive RMS chip set: The Microbox 3 manufactured and sold by UK-based company "Micro Concepts" from Cheltenham! I can only find it described in detail one place and that is in the Electronics & Wireless World issue of May 1986. On page 63, it is announced as the British rival to the Amiga and the description leaves little doubt:

Microbox 3 is a colour graphics computer designed around the 68000 (or 68010) processor running at 8MHz and Motorola's Raster Memory System chip set. It offers 40 different screen modes, with resolution ranging up to 640 by 500 pixels, plus features such as a 4096- colour palette, eight reusable sprites and a virtual screen of up to 512K in size with smooth horizontal or vertical scrolling.

Apart from omitting the parts numbers themselves (68486 & 68487) the specification match the RMS exactly, and it is explicitly named Motorola's Raster Memory System chip set. There's little doubt that this is the real thing:

enter image description here

In the same magazine, I found ads from Micro Concepts for the Microbox 3 in a number of issues, e.g. May 1987 (page 463) and October 1987 (page 1018).

Features include:

  • 68000 CPU @ 8MHz clock
  • 512K dynamic RAM
  • 64K static RAM
  • 128K EPROM
  • Onboard graphics controller offers:
    • 80 column, 24 row, 16 colour text
    • 640 x 480, 4 colour graphics
    • 320 x 480, 16 colour graphics
  • Floppy disc controller
  • Dual serial RS232 ports
  • Centronics printer port
  • Up to 48 lines of parallel I/O
  • Runs OS-9/68K, TRIPOS and CP/M-68K

There are a number of other mentions of the RMS chip set in very disparate places around the world, but the above system is the definite proof that Motorola DID release it and sold it and that has been used. The greatest mystery is how this could have gone under the radar. According to one source, the RMS was showcased at the winter CES 1984 in Las Vegas. In contrast, the Amiga prototype drew quite a lot of attention at the summer CES that very same year!

The few only other sources confirming the existence of the Motorola RMS beyond 1984:

All these are leads worth exploring further. Of course, full attention should be directed at the UK company who developed and sold the Microbox 3 boards! With loads of luck, there may still be RMS specimens knocking about out there, though I wouldn't hold my breath. :-(

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