Unisys Corp yesterday duly introduced its challenging desktop mainframe at the bottom end of the Burroughs-derived A series baptising the thing the Micro A, and claiming it to be the cheapest as well as the smallest mainframe on the market. The company has shrunk an entire A Series processor, including MCP/AS operating system, onto a 2 by 2, 10-layer ceramic chip package known as the Single Chip A Series Mainframe Processor, or Scamp. Fitted with an AT bus, the machine is packaged inside the Personal Workstation Model 800, combining the 48-bit Scamp processor surrounded with 2.5Mb static RAM, widh 12Mb of memory and an input-output controller, on a standard, 80386-based AT-bus board. Connection to a maximum of seven peripheral devices is provided via a SCSI board from Western Technology, which comes complete with a 280Mb disk drive and 150Mb cartridge tape. The 80386-based Personal Workstation alongside which the processor sits has 1Mb memory of its own and runs under OS/2, booted from a dedicated 20Mb disk that also holds MCP/AS, serving as the input output subsystem. MS-DOS and OS/2 applications can be run on the 80386, but only when the Micro A processor is off line. Micro A also features a data communications subsystem, housed on an 80286-based Data Communications Host Adaptor board from Emulex Corp. The 80286 comes with its own 512Kb memory and supports up to four separate lines and three communication protocols concurrently, providing SNA and X25 links to other systems and networks. A maximum eight lines can be achieved by adding a second board. Use of the 16-bit AT bus on the 48-bit processor slows the performance of the MCP/AS Master Control Program, but in a series of RAMP-C benchmark tests designed to verify a two second response time and 70% processor usage, Unisys claims that the Micro A out-performed IBM’s AS/400 B20 by 8%, and the B10 by as much as 40%. UK price for the Micro A is UKP25,000, including pre-loaded operating system software and Linc II generator.