Instrumentation XT personal computer

Mainly in corporate environments, various administrative and record keeping applications

Structure

Central unit

• CPU: Intel 8086 microprocessor, clock speed 4.77 MHz
• main memory: 1 MB DRAM
• calculator: ALU built into a microprocessor

Periphery

• backups:
  • 20 MB hard drive ( Seagate 5.25”)
  • 360 KB floppy disk, (5.25”, FDD adapter card)
• external devices:
  • keyboard (9-pin serial interface card)
  • console monitor (CGA or Hercules interface card)
  • Centronics line printer (parallel interface card)

The interface cards for external devices were connected to an 8-bit ISA bus. The serial and parallel interfaces, which were initially mounted on separate interface cards, were later placed on a Multi-IO card, which also had a battery to maintain date and time information.

Operation

Screen resolution:

• In text mode 25 lines 80 chpl

• In graphical mode:
  • monochrome monitor: 720*348 pixels, green or amber
  • color monitor:
    • 320*200 pixels, 16 colors, or
    • 640*200 pixels, 4 colors

With a CGA and Hercules card and an additional monitor, a dual-monitor system could be created (for example, for debugging)

Program set

• operating system: MS-DOS 3.x
• compilers:
  • BASIC
  • C
  • Turbo Pascal
  • dBase, FoxBase

Historical curiosities

The Turbo button could increase the clock speed to 12 MHz, which compatible expansion cards usually could not take advantage of.

Programs that reached a dead end could be interrupted with the Reset button.

A separate key was used to prevent unauthorized access.

The hard drive's moving read/write heads could be set to a parking position before being turned off to avoid possible data loss.

Small businesses have made expansion cards for special applications, such as measurement technology.

Resources

Brief description: P286 / Instrumentation Technology Cooperative

Detailed description: Instrumentation XT