The 8-bit home computer EACA “Colour Genie” EG2000
This 8-bit keyboard computer will soon be leaving me again, as I unfortunately don’t have the time to spend more time with it.
Nevertheless, I would like to take this (last) chance to introduce you to a rather rare computer from the early 1980s.
First of all, I want to clarify why this article appears in the Tandy RadioShack category: The company EACA International LTD from Hong Kong distributed Pong-like video game consoles from 1975 and later began producing clones of well-known computers. These included replicas based on Tandy RadioShack’s TRS-80 Model 1, which were manufactured and marketed by EACA as “Video Genie”.
In Germany, the “Colour Genie” was sold by Trommeschläger (TCS) and other computer retailers and was intended to compete with the Commodore VIC-20 and the Sinclair ZX Spectrum. Trommeschläger had already been quite successful on the German market with the “Video Genie” series. With the TRS-80 clones based on the Zilog Z80 8-bit CPU, the company was able to close the gap in Germany to the competition from the Commodore PET and Apple II with MOS 6502 CPU.
With the sound and graphics capabilities in the emerging home computers, such as the Commodore VIC-20, Atari 800 or TI-99/4, EACA’s desire for such features in its own computers also grew.
Now it could be assumed that EACA simply released another replica of an existing computer. Tandy had already launched a new model series with color graphics and sound in 1980 with the TRS-80 Colour Computer. However, Tandy’s CoCo was no longer compatible with the predecessor models of its own TRS-80 series, as it had a completely different CPU, the Motorola 6809E, and therefore also a different ROM.
In contrast, EACA now independently developed a graphics and sound extension based on the existing platform for the Z80 CPU. The LEVEL II BASIC in the ROM was also expanded to include graphics and sound commands.
The original LEVEL II BASIC, which was developed for RadioShack’s Model 1, was based on Microsoft BASIC. This version was also used in the “Video Genie” model series from EACA.
For the “Colour Genie”, this BASIC – which was then called “Colour BASIC” – was expanded to include graphics and sound commands. However, care was taken to ensure that it was otherwise compatible with the “Video Genie” BASIC. This meant that Model 1 and “Video Genie” software could still be executed with “Colour Genie”. EACA thus implemented the compatibility that customers had actually wanted for the Tandy CoCo.
Unfortunately, this compatibility was not implemented consistently throughout. Annoyingly, EACA used a different recording format for cassettes of all things. This meant that TRS-80 or Video Genie cassettes could not be used with the “Color Genie” without further ado. However, by reverse-engineering the cassette interface, the Trommeschläger company succeeded in developing software with which TRS-80/”Video Genie” software could be transferred directly to the “Colour Genie” via a tape cable.
There was now also a separate text and graphics mode for the screen display. This had the advantage that high-resolution graphics could be set up in the background while the text mode was still displayed in the foreground. It was then possible to switch to graphics mode, which displayed the entire graphic immediately.
Unfortunately, the spread of the computer was limited. This certainly had something to do with the fact that Commodore, Sinclair, Atari and other manufacturers in particular flooded the market in the first half of the 1980s with often better and more powerful computers with graphics/sprite and sound capabilities. In the end, there were an estimated 190 games for the “Color Genie”, many of which were also developed in Germany, as illustrated by their popularity in this country.
The specs
Here is a summary of some technical data on the “Colour Genie” EG2000:
- Z80 CPU 8-Bit @ 2.2 MHz
- BASIC ROM 16 kB
- RAM 16 kB expandable to 32 kB by plug-in card
- Video Controller Motorola 6845 (Textmode: 40×24/40×25 16 Colors, Graphic Mode: 160×96/160×102 Pixel 4 Colors)
- Sound Chip General Instruments AY-3-8910 (3 Sound Channels, 1 Noise Channel), internal speaker and Audio-Out via Cinch.
- RF and Composite Video Output
- Expansion slot for Floppy-Controller or software moduls
- 1200 baud DIN Cassette interface
- 5 pin DIN serial connector
- 5 pin DIN Light Pen connector
- Parallel port for joysticks and printer
- Keyboard with 63 keys and 4 programmable function keys.
From around April 1983, the “Colour Genie” was delivered with newer ROMs. These models can also be recognized externally by the now built-in level meter for the cassette drive (see picture). The updated ROMs also changed the resolution in text mode to 25 instead of 24 lines and in graphics mode to 160×102 instead of 160×96 pixels. New commands were also added to the ROMs and errors were corrected.
Colour BASIC
Finally, a few small exercises with Color BASIC:
As is usual with all Z80 TRS-80 models, the computer displays the message “MEM SIZE?” with green letters on a black background when it is switched on. Here you could reserve memory for machine code programs. After confirming the message with the RETURN key, the BASIC prompt appears. The free RAM memory available is displayed with the command: ?MEM. If the key is held down when the Colour Genie is switched on, the graphics memory is added to the available BASIC memory.
When working with BASIC, switches the character set from ASCII to the graphic symbols, which are also printed on the front of the keys. Otherwise, the key combination + is used to switch to high-resolution graphics mode.
Colour BASIC also has helpful commands for the programmer: the AUTO command can be used to switch on automatic line numbering and the EDIT command helps when editing individual lines of code. TRON and TROFF are used to switch the trace mode on or off when executing a program. This means that the current program line is always displayed on the screen during execution.
Also very practical and standard in modern programming languages are commands such as ERROR, which simulates an error, and ON ERROR GOTO, which prevents the program from aborting when an error occurs. These are all helpful functions that a C64 BASIC programmer, for example, would sorely miss!
Entering the SYSTEM command takes you to the machine code editor. Machine code programs can be loaded from here.
A few small BASIC utility programs:
10 REM Ausgabe des Zeichensatzes
20 CLS:COLOUR 1
30 FOR Q=32 TO 128
40 PRINT CHR$(Q);
50 NEXT
60 PRINT10 REM Ausgabe des vollständigen Zeichensatzes
20 CLS:COLOUR 1:CHAR4
30 FOR Q=0 TO 255
40 POKE &H4400+Q,Q
50 NEXT
60 PRINT@400,"";: REM Cursor in die Mitte des
Bildschirms verschieben, damit Ausgabe nicht durch das READY Prompt überschrieben wird10 REM Überprüfung der ROM Version, bei neuen ROMS ist die Zeilenzahl im Textmodus gleich 25
20 A=PEEK(&H42F9)
30 IF A=25 THEN PRINT"Neue ROM Version entdeckt..."CLOAD loads a BASIC program from cassette RUN starts a BASIC program LIST shows the source code of the BASIC program in memory LLIST prints the BASIC program in memory CSAVE "name" saves the BASIC program in memory to cassette PRINT MEM displays the available BASIC memory
Games
Most games for the “Color Genie” are available in machine language. To load a machine language program, enter SYSTEM and at the *? prompt again to load the program. During loading, a flashing * is displayed in the top right-hand corner. After successful loading, the *? prompt appears again, now enter / to start the program.
Key functions
| <RST>+<RST>+<R> | Reset the computer |
| <BREAK> | interrupts a running BASIC program, interrupts the listing of a program, switches from graphics to text mode |
| <BREAK>+<CLEAR> | Most machine language programs are programmed so that they are interrupted when the two buttons are pressed |
| <RPT> | repeats the last character entered |
| <LOCK> | Locking switch for lower case letters |
| <F1>-<F4> | the function keys are assigned different BASIC commands, but can also be programmed |
| <MOD SEL> | Enter the graphic characters shown on the front of the buttons, if the button is held down when switched on, the graphic memory can be used as a program memory |
The most important commands for disk operation are:
CMD "F formats a floppy disk in drive 0 CMD "F1 formats a floppy disk in drive 1 CMD "I shows the contents of a floppy disk (in drive 0) LOAD "name/BAS or LOAD "name loads a BASIC program SAVE "name/BAS or SAVE "name saves the BASIC program in memory to diskette CMD "Sname/CMD loads a machine language program and starts it KILL "name" deletes a program from floppy disk
Hopefully I was able to give you a little insight into the world of the EACA “Color Genie”. Unfortunately, I don’t have the time to spend more time with the computer. So it will go on to another club colleague.