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ADDS ASCII Front2.jpg
Model no. ADDS ASCII
Branding ADDS
Manufacturer NMB
Features ADDS terminal compatibility
Keyswitches Hi-Tek Series 725
Interface RJ-11 male cable non-removable
Rollover 4 Key Rollover


The ADDS ASCII is an OEM ADDS terminal keyboard using NMB Hi-Tek 725 switches. The switches are white 2 eye linear switches for all switches except the spacebar, which uses a green 2 eye switch. This keyboard is another version of the NCR 4950 but has the ADDS badge instead. All other internals appear to be identical as the NCR 4950.


This keyboard uses both the ADDS protocol and the AT protocol. Switching between the two protocols is done through jumpers located on the PCB.



Switching the board to PC/AT mode can be done via jumpers being installed only in the following locations: JP1-JP4. Soarer's converter can be used with either a teensy or pro micro to internally convert the board to USB.

pin# Top
6 Reset Red
5 Data Green
4 Case GND
3 Clock Yellow
2 SG GND Black
1 VCC +5V White



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