80-Bus News

Review of the Gemini Galaxy 2

Introduction

The Galaxy 2 computer by Gemini Microcomputers is the result of progressive development from the earlier Galaxy 1 computer, incorporating a number of improvements which further enhance the performance of the machine. Gemini have retained the modular card approach with the Galaxy 2, an approach which has always been the province of ‘professional’ computer design. The ‘single board’ approach adopted by many computer designers has advantages in terms of production cost, but disadvantages in terms of flexibility, expansion and repair. The single board approach is probably suitable for the business user where, once the specification of the machine has been decided, there would be little likelihood of needing expansion. However, Gemini have produced a modular machine equal to or better in performance than most popular single board computers, and at a very competitive price. Because of its modular design many permutations of the basic machine may be manufactured without the extra cost involved in manufacturing ‘specials’, and with all the advantages of expansion and flexibility as we shall see later. This makes the Galaxy 2 not only competitive in the business market, but ideal in the system development or laboratory situation, an area where many single board computers could not compete.

Specification

The basic specification of the machine is similar to many other machines using the CP/M operating system: a high capacity twin disk system, Z80A processor, 64K of RAM, 80 by 25 VDU type display, etc. Unlike many other CP/M machines, however, the Galaxy 2 has an internal bus with three slots spare conforming to the popular 80-BUS/​Nasbus standard, allowing expansion with cards manufactured by a number of other companies.

Appearance

The Galaxy comes complete with all leads and necessary connectors to plug in directly. A quality 12″ green or amber screen monitor is also supplied. The Galaxy case is steel measuring 18″ by 12″ by 7″, attractively finished in cream and matt black paint. The paint finish is a high temperature baked resin finish and is particularly hard wearing, very easy to keep clean and not prone to scratches. In these days of flimsy vacuum formed plastic cases it is a delight to see the solid and robust case of the Galaxy, which whilst boxy in shape is both pleasantly and conveniently proportioned. The solid case makes the Galaxy feature as one of the very few computers you could actually stand on without damage. Not a major sales point perhaps, but one that should appeal to the educationalists or to users where hard physical use (or abuse) of a computer takes place. The separate keyboard case is also of steel construction, finished in a similar fashion to the main computer case, and is sufficiently low profile for experienced typists to find it comfortable in use

The only features on the front face of the computer are the vertically mounted twin disk drives and an LED power on indicator. The back panel has all the necessary sockets and connectors. A DB25 connector is provided for direct connection to RS232 printers or a modem, a 36 way Amphenol type connector for direct connection to printers using the parallel ‘Centronics’ protocol. A DB15 connector is provided for keyboard connection and DIN sockets for external tape I/O and light pen connection and a PL259 socket for the video output. The