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Maxi-Switch 6000 Series



Maxi-Switch 6000 series (or Series 6000) covers an unclear range of mechanical keyboards and switches. The only switches confirmed from 6000 series are those colloquially termed “Maxi-Switch vintage linear”, believed to be a derivative of SMK JM-0400 series.


The oldest advertisement discovered to date (for “6000 series”) is from Electronics magazine in January 1979; see Documentation below). The keyboard thus advertised was microprocessor-driven with mechanical switches. A later advertisement notes, “Electronic hysteresis eliminates switch tease and multiple char output problems.” There are photograph showing the keyboards, but no way to determine what switch types are used. A later advertisement in Design News magazine in 1983 for Series 6000 and 8000 Series depicts the switch contacts alongside an assembled switch, confirming that 6000 Series is what has until recently been termed “Maxi-Switch vintage linear”.

The scope of 6000 series is unclear. The MAX-II (or MAX-11) keyboard (see Documentation) is documented as being 6000 series, giving us the specifications for the switches. David Given’s Maxi-Switch 2160029 appears to be a MAX-II, and it has “Maxi-Switch vintage linear” switches, as do all other Maxi-Switch keyboards with part numbers in that range. The original MAX advertisement shows the same PCB holes (for unpopulated key stations) as David’s apparent MAX-II, suggesting that the original MAX keyboard was also “vintage linear”. However, the advertisment also notes that the switches have wiping action, which is not a known behaviour of that type of switch.


6000 series switches are a variant of the mechanical portion of SMK JM-0400 series. While not officially confirmed, the fact that 8000 Series is also identical to the corresponding SMK product all but proves that SMK either licensing their tooling or producing the switches on Maxi-Switch’s behalf just as they did for NEC.

The majority of switches bear a “Maxi” logo on the base. The decision of SMK to place the logos there means that there is no way to positively identify whether any particular switch is an SMK, Maxi-Switch or NEC product, although the choice of colours is a clue: a blue base (and thus retention clips) tends to suggest Maxi-Switch (although black bases were also used), while an all-black shell and blue plunger implies NEC. Switches intended for wider keys tend to have a beige body and brown plunger as with SMK switches. The plunger is generally black, but white and cyan are also known. There is a rare example of these switches with top branding, in an Intelligent Systems Corp Intecolor 101894.


No documentation has been found for the switches; the specifications below are taken from the Standard-Tastatur MAX-II product leaflet, as given under Documentation:

Total travel 0.120±0.017″ (3±0.4 mm)
Pretravel 0.050″ (1.27 mm)
Overtravel 0.070″ (1.77 mm)
Operating force 3.5±1 oz (100±30 gf) standard
Bounce time Below 3 ms
Contact rating 12 V DC, 100 mA
Initial contact resistance Below 1 Ω
Operating lifetime 10 million cycles

The bounce time, rated lifetime and electrical rating match the specifications of SMK JM-0400 mechanical switches when advertised in 1979. The seemingly later SMK J-M 9031 flyer gave the rated lifetime as 100 million cycles, and the operating force of 90±30 grams (90±20%) and pretravel (at exactly half way) of 0.06″ (1.5 mm) both differ from Maxi-Switch’s specifications given above. However, the 1983 announcement for Series 6000 does cite a “100-million-plus operation life cycle”.


As noted, no product literature has been recovered. The following switch models are known from NATO Stock Number (NSN) records:

Model Plunger colour NSN Notes
600001 Listed on obsoletepartfinder.com
600014 White 5930-01-243-3317 HP part 3101-2463; standard alphanumeric keys switch (HP 9825/9835)
600015 White 5930-01-243-3318 HP part 3101-2576
600016 Brown 5930-01-243-5645 HP part 3101-2577
600031 5930-01-375-0229
600032 5930-01-375-0228
600034 5930-01-375-0227

The HP 9825/9835 keyboard uses Maxi-Switch “vintage linear” switches, and the alphanumeric area switches have been seen with both black () and white () plungers. The white plunger variety corresponds with the documented plunger colour in the NSN record for that HP part.

Example keyboards

Keyboard PCB code Part number Date Country Serial Notes Reference
Cybernetic Data Products keyboard 630010-09 2160029 USA 1488-440 Deskthority
Unidentified ASCII keyboard 630015-02 2160014 ca. 1979 436-090 Deskthority
Unidentified keyboard 630010-10 2160029 1982-10-14 USA 5996 Imgur
Commodore PET add-on keyboard 630011-03 2160010 749-199 Deskthority
Unidentified keyboard 630010-10 2160094 1983-03-21 USA 1191 Deskthority
Billings 6000 keyboard 630067-03 2160148 1983-04-22 USA 1123 Flickr
Kaypro II keyboard 630184-02 2160150 1983-07-29 USA 017098 oldcrap.org
Xerox 928-900451 630107-02 110S80577 2160132 1984-01-11 USA 016020 Flickr
Multi Metrics Geomet 200 KYBD 2160177 2160177 1984-07-24 1228 Based on the HP 9826/9836 keyboard Flickr
Maxi-Switch 2160029 (MAX-II or MAX-11?) 630010-11 2160029 1984-10-05 USA 016703 KAref


All material was scanned by Bitsavers unless otherwise noted.