Back to NCR ComputersNCR 725 Computer

 

This machine is a "barn find", discovered while following up a lead for a glass TTY terminal. Its owner obtained it at auction in the early 1980s for a side-project that did not proceed, and it was then put into a barn and left for over 30 years. It appears to be complete and largely unmolested. The massive power supply appears to have been the main site of past work and this may be one reason for the machine being put aside. There is some external rust but the internal components show very little corrosion. The 16k core memory unit is the main source of anxiety in this regard but it is likely to be more hazardous to dismantle this component for assessment.

The machine is currently in storage while its restoration prospects are considered. Reasons for optimism include:

  • It appears to be commplete, with no serious damage or deterioration
  • It is based on simple TTL technology, this is repairable with sufficient data and time
  • There appears to be a strong ex-NCR community that may well have kept useful data and/or software

DoPECC would like to be able to restore this machine but will require the following before being able to proceed:

  • any and all technical and circuit information for the 725 computer, 605 processor and peripherals
  • any software, on media or as listings. The entire software environment has been lost
  • recollections, stories or general information from past users or technicians

Please send any information or assistance via the About/Contact link.

 

NCR 725 Store-Level Computer

The NCR 725 was the central element of NCR's retail point of sale system in the early 1970s. The 725 was attached to intelligent cash registers such as the NCR 280 via an NCR-designed and patented communications network. Sales data was collected, processed and sent to a central mainframe via modem or output to tape for transfer to the mainframe.

The computer was designed to be put in the store's general office and all components were nicely integrated into a single unit.

 

 

The 725 contains all of the elements of an early mainframe - control panel switches, blinkenlights and tape reels.

The main tape drive in an HP7970, an early HP drive that was designed for computer mass-storage.

Unusually, there are also two casette tape drives. These are located beneath the control panel and were mostly used to load system software.

 

 

 

The control panel is typical for an early computer, but perhaps unexpected in a machine designed for end-users rather than programmers. It would be interesting to know how this was used by typical retail store staff.