A PC on A PC BOARD: AMOTHER BETWOBXIRG METHOD
Craig A. Bergman · 1990
A network ‘method is described which utilizes PC compatible processors, complete with memory and I/O, mounted on PC boards. This method incorporates the advantages of using serial connections to terminals without the disadvantages of multitasking a single microproceesor. The capabilities and limitations of the networking method are described and compared with a more conventional Ethernet network utilizing the Novel1 Netware operating system. A 5-user network has been installed this winter utilizing ‘286based microprocessors with serial terminals. A ‘386-based server is used with a bus expansion box for the uBer boards. Two serial and one parallel printers are available as network resources. One terminal, with one additional serial printer and buffer, are serviced. by a pair of modems over a leased telephone line to a location two miles away. The features of the operating system are described, including online meseages between ueers, commanding and viewing other users‘ terminals, disk sharing, and print queuing. Running PC software on serial terminals which have no function keys and no Alt key presents special problems in terms of the terminal driver software. The steps taken to modify an existing terminal driver routine to support a different terminal are described. IITRODUCTIOI An existing 5-user system was becoming slow, unreliable, and increasingly difficult to support. The system was a 6-year-old Northstar Horizon with a 30 Meg hard drive, tape backup, and 5 user boards, each connected to a TeleVideo 914 serial terminal. A remote user was connected through a pair of 1200 baud modems and a 2-mile leased phone line. The system printers consisted of two serial and one parallel printers connected to the server computer, with an additional serial printer connected to the remote terminal‘s auxiliary port.