Maxi-Switch 6000 Series

Contents

• Overview
• Keyboards
• Switches
  • Specifications
  • Models
• Example keyboards
• Documentation

Overview

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.

Keyboards

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.

Switches

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.

Specifications

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:

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”.

Models

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

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

Documentation

All material was scanned by Bitsavers unless otherwise noted.

• MAX keyboard advertisement, BYTE, Vol. 3 No. 9, September 1978 (Internet Archive, unknown origin)
• MAX keyboard advertisement, Computer Design, September 1978
• 6000 Series keyboards advertisement, Electronics, Vol. 52 No. 1, January 4 1979, page 84
• 6000 series advertisement, Computer Design, April 1979
• M-53 ASR-33 keyboard advertisement, Computer Design, September 1979
• Standard-Tastatur MAX-II product leaflet, scanned by David Given (the original was already a poor quality photocopy)
• Series 6000 and 8000 announcement, Design News, Vol. 39 No. 24, December 19 1983, page 16 (scanned by the Linda Hall Library)