website/content/museum/texas-instruments-ds990.md

---
title: Texas Instruments DS990
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1980'
cpus:
- TMS-9900
params:
  name: DS990
  image: /media/museum/photos/texasinstr_ds990_system_s1.jpg
  company: /companies/texas-instruments
  company_name: Texas Instruments
  specs:
  - label: NAME
    value: DS990
  - label: MANUFACTURER
    value: Texas Instruments
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1980'
  - label: END OF PRODUCTION
    value: Unknown
  - label: BUILT IN LANGUAGE
    value: None
  - label: KEYBOARD
    value: 88 key with numeric and arrow keypads, 10 function keys and 8 state led
  - label: CPU
    value: TMS-9900 (16-bit)
  - label: SPEED
    value: Unknown
  - label: RAM
    value: 64 KB
  - label: ROM
    value: 12 KB
  - label: TEXT MODES
    value: 80 columns x 24 lines
  - label: GRAPHIC MODES
    value: None
  - label: COLORS
    value: Monochrome
  - label: SOUND
    value: Beeper
  - label: SIZE / WEIGHT
    value: 58.5 (W) x 58.5 (D) x 46.5 (H)
  - label: I/O PORTS
    value: 3 x serial, 1 FDD port
  - label: BUILT IN MEDIA
    value: None
  - label: OS
    value: DX10, DNOS
  - label: POWER SUPPLY
    value: Built-in modular switching PSU
  - label: PERIPHERALS
    value: TI extension cards
  - label: PRICE
    value: Unknown
  tabs:
  - photos
  - hardware
  forum_thread: 999
  photos:
  - title: LARGER VIEW
    subtitle: ''
    text: ''
    image: /media/museum/photos/texasinstr_ds990_system_s2.jpg
  - title: TOP VIEW
    subtitle: ''
    text: ''
    image: /media/museum/photos/texasinstr_ds990_topview_s1.jpg
  - title: SIDE VIEW
    subtitle: ''
    text: ''
    image: /media/museum/photos/texasinstr_ds990_rightside_s1.jpg
  - title: REAR SIDE
    subtitle: ''
    text: Notice the three serial ports and the (blue) floppy disk unit connector.
    image: /media/museum/photos/texasinstr_ds990_rearside_s1.jpg
  - title: KEYBOARD
    subtitle: ''
    text: ''
    image: /media/museum/photos/texasinstr_ds990_keyboard_s1.jpg
  - title: KEYBOARD DETAILS
    subtitle: ''
    text: Left and right keypads. Notice the 8 status leds.
    image: /media/museum/photos/texasinstr_ds990_keyboard_s2.jpg
  - title: RUNNING
    subtitle: ''
    text: Main menu of the TI utilities disk.
    image: /media/museum/photos/texasinstr_ds990_bootscreen_s1.jpg
  - title: COMPLETE SYSTEM
    subtitle: ''
    text: With a dual 8" floppy disk unit and a serial printer/terminal.
    image: /media/museum/photos/texasinstr_ds990_completesystem_s1.jpg
  - title: 'INSIDE #1'
    subtitle: ''
    text: ''
    image: /media/museum/photos/texasinstr_ds990_inside_s2.jpg
  - title: 'INSIDE #2'
    subtitle: ''
    text: |-
      A large cooling fan separates the logic cards and the power supply unit.\
      **(1)** Serial cards dedicated to video terminals or printers\
      **(2)** CPU card\
      **(3)** RAM card\
      **(4)** Display card\
      **(5)** Floppy disk controller cards\
      **(6)** Modular switching PSU cards\
      **(7)** The large fan is enclosed between the logic cards and the PSU
    image: /media/museum/photos/texasinstr_ds990_inside_s1.jpg
  - title: 'INSIDE #3'
    subtitle: ''
    text: A single backplane supports the PSU cards (green slots) and the logic cards ((black slots).
    image: /media/museum/photos/texasinstr_ds990_backplane_s1.jpg
  hardware:
  - title: INSIDE THE FD UNIT
    subtitle: ''
    text: 15 years of advances made in technology have elapsed between this massive dual 8" FD unit (about 30 kg) and a 100-gram 3.5" floppy drive which provides more than twice as much storage capacity.
    image: /media/museum/hardware/texasinstr_ds990_fdunit_s1.jpg
  - title: FLOPPY DISC DRIVES
    subtitle: ''
    text: |-
      Both sides of the 8" Qume floppy disk drive.\
      Some technical features:\
      • 300 rounds per minute\
      • 128 bytes per sector\
      • 26 sectors per track\
      • 77 tracks per diskette\
      • 3328 bytes per track\
      • 256,256 bytes per diskette
    image: /media/museum/hardware/texasinstr_ds990_fddrives_s1.jpg
  - title: OMNI 800 TERMINAL/PRINTER
    subtitle: Model 820 RO (Read Only)
    text: |-
      Under the Omni 800 label, T.I. released numerous professional printers and terminals. Most of them acted as a remote input/output unit.\
      This version has a covered operator control keypad, but other models featured a complete typewriter keyboard.
    image: /media/museum/hardware/texasinstr_ds990_printer_s1.jpg
  - title: OMNI 800 TERMINAL/PRINTER
    subtitle: Model KSR
    text: Thanks to its typewriter keyboard, this version was a true interactive terminal.
    image: /media/museum/hardware/texasinstr_ds990_printer_s2.jpg
  - title: 'CPU CARD #1'
    subtitle: ''
    text: Notice the beeper and the keyboard connector on the right-hand side.
    image: /media/museum/hardware/texasinstr_ds990_cpucard_s1.jpg
  - title: TMS-9900 PROCESSOR
    subtitle: ''
    text: A nice ceramic version of the 16-bit TMS-9900 CPU.
    image: /media/museum/hardware/texasinstr_ds990_processor_s1.jpg
  - title: 'RAM CARD #1'
    subtitle: ''
    text: 64 KB RAM card populated with 32 x 4116 RAM chips (16K x 1 bit).
    image: /media/museum/hardware/texasinstr_ds990_ramcard_s1.jpg
  - title: 'RAM CARD #2'
    subtitle: ''
    text: ''
    image: /media/museum/hardware/texasinstr_ds990_ramchips_s1.jpg
  oc_id: 1025
  source:
    url: https://web.archive.org/web/20230330025208/http://www.old-computers.com/museum/computer.asp?c=1025
    date: '2023-03-30'
---

This DS990/1 system was the basic model of the DS990 series which was also comprised of the **990/2**, **990/4**, **990/10** and **990/12** models. They were targeted as multi-user business systems, and ran the DX10 then the DNOS (Distributed Network Operating System) OS's.

The 990/1 was the only version including its own video display, although up to three serial dumb video terminals could be connected as well. Other versions had a separate main unit managing several terminals, mass storage and printers.

The core of the system was a true 16-bit microprocessor, the TMS-9900, also made by T.I., and mounted later in the first 16-bit home computer, the [TI-99/4](/museum/texas-instruments-ti-99-4a/). Apart from the dumb terminals, interface cards allowed to connect a serial printer and a single or dual 8" floppy disk unit.