80-Bus News


May–June 1984, Volume 3, Issue 3

Page 42 of 51


80-BUS ‘Pluto’ colour board from IO Research. The number of permutations of this board should be the subject of an article of its own! Started off with on-board 5MHz 8088 processor, 640x288 resolution, 8 colours, two screens. Then there were 640x576 options, 8MHz options, and the current product is normally 768x576, 8 colour, 8MHz 8088, although the 640x576 (640x288x2) version can also be ordered! Also see other IO 800 products. Any volunteers for a ‘Pluto Family’ article?


80-BUS floppy disk controller board. Fully compatible with the GM809 that it replaced, but with a previously unused bit of the control port being used to switch the board between 5.25″ and 8″ operation, allowing both types (and 3.5″ drives that electrically ‘look’ like 5.25″ drives) to be attached to the GM829 at the same time. In addition the board contains a SASI interface that is used for the connection of Winchester disk controller boards. For an example of the flexibility of this board look at the Gemini Galaxy M-F-B family, the top model of which has a 16 Mbyte Winchester, double-sided 96tpi 5.25″ drive, double-sided 48tpi 5.25″ drive, double-sided 8″ drive, and double-sided 3.5″ drive all connected via a GM829.


Mini-pallette board from IO Research, available as an add-on for the IO828 ‘Pluto’ (although the latter then needs a new monitor EPROM). Gives the user the ability to select any 8 screen colours out of a Pallette of 256. This can be particularly impressive if 8 grey levels are selected, the resulting picture almost looking as good as a B&W photograph. Two look-up tables are supported, and the user may switch rapidly between them.


5 slot 80-BUS backplane (with 1″ pitch between boards) including 77-way 80-BUS edge connectors. Discontinued as a built product, but the PCB continues to be available.


80-BUS SVC (Super Video Controller) board. Fully compatible with the GM812 IVC that it replaces, but with the following enhancements. 6MHz Z80B CPU used, which in conjunction with other hardware and software changes provides far greater speed. Second text mode is now 40x25. Graphics mode added of 256x256, with on-board monitor containing line and circle drawing routines, polygon fill routines etc. Buzzer added. Attributes added – half-intensity characters, half-tone background, blinking. All 256 characters are now user-definable – on power up they are down-loaded from the on-board monitor, and this includes switch options for French, Danish, German, Swedish, American and English characters. Serial keyboard input option added – although this is of Gemini’s own design (see GM852).


Gemini’s 80-BUS RAM-DISK board. Provides 512K bytes of RAM driven via a ‘disk-like’ 80-BUS I/O port interface of ‘track’, ‘sector’ and ‘data’ ports. On-board switch allows up to 16 boards to be decoded at the same port addresses, theoretically providing up to 8MBytes!

Page 42 of 51