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.
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:
- QEX April 1984
- IEEE MICRO'S PRODUCT Product Summary (1984)
- Radio Electronics October 1984
- Dragon User November 1985
- Die Zukunft der Informationssysteme (September 1986)
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:
- How could the RMS have been developed in conjunction with the CoCo3, if it was developed in the year the CoCo2 was developed?
- 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!
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.