ACT Sirius 1

The ACT Sirius 1 was the European version of the Victor 9000, the advanced 16-bit business computer designed by Chuck Peddle’s team. Its high-resolution display, large-capacity variable-speed floppy drives and generous expansion made it a formidable alternative to the early IBM PC.

ACT distributed the system throughout Britain and Europe with MS-DOS or CP/M-86. Strong sales, helped by IBM’s delayed European PC launch, gave ACT the resources and market position needed to create its own Apricot computers.

Notable Features

• Variable-speed floppy drives stored substantially more data than early IBM PC drives.
• The 800 x 400 monochrome display supported detailed text and graphics.
• Four internal expansion slots and an optional 8087 supported demanding business applications.

Historical Significance

• Sold in America as the Victor 9000 and in Europe as the ACT Sirius 1.
• Became one of Europe’s leading early 16-bit business micros and directly influenced the Apricot PC.

Collector’s Notes

• Its disk format and hardware are not IBM PC compatible despite running MS-DOS.
• Variable-speed drives, keyboard condition and original system disks are important restoration considerations.

Specifications

Technical Information
Name	ACT Sirius 1
Manufacturer	Applied Computer Techniques Ltd
Launched	Monday, March 1, 1982
Launch Price	£2,395
Country	United Kingdom
CPU	Intel 8088 at 5 MHz
Units Sold
Operating System	MS-DOS, CP/M-86 and Microsoft BASIC-86
I/O	Two RS-232 ports, Centronics/IEEE-488 interfaces and four internal slots
Keyboard	Detached full-travel programmable keyboard
Storage	Two 5.25-inch variable-speed floppy drives; hard-disk options
Sound	Programmable tone/audio support
Graphics	800 x 400 monochrome graphics
Display	Integrated green monochrome CRT; 80 x 25 text
ROM	System firmware on ROM
RAM	128KB or 256KB standard; expandable to 896KB
CPU Speed	5 MHz