The keyboard of the AMSTRAD CPC 664 - operation, models and catering

I-IAmstrad CPC 664 is a relatively rare model launched in 1985 between CPC 464 and CPC 6128. It is a computer with an intermediate keyboard between the other two models, using an original technical design.

This keyboard keys low represents an evolution from the first model (CPC 464 v1), but remains different from the keyboard of CPC 6128. If you have a CPC 664 or want to repair it, this article explains how it works, the variants available and how to maintain it.

Technical specifications of the CPC 664 keyboard

The keyboard of CPC 664 adopts its own design:

• Keys low – more modern and ergonomic
• Spring + gum piston under each key – ensuring tactile return and electrical contact
• Flexible contact sheet – with flexible printed circuits
• Integrated flexible tablet – made of a single holder with the membrane
• Metal support plate – susceptible to oxidation with age
• Support keys rigid PVC – guides pistons and stabilizes supports

An intermediate model with little dissemination

Although technically advanced, the CPC 664 did not see widespread distribution.It is a transitional model between the CPC 464 and the CPC 6128, but it does not share exactly the same internal architecture.

Unlike the second model of CPC 464 and CPC 6128, the keyboard of CPC 664 uses a spring + gum piston system under each key, not an elastomer pad or complete membrane. In addition, the contact sheet is equipped with an integrated sheet, making the structure compact but fragile.

Restore CPC 664 Keyboard – Practical Guide

Over time, flexible foil keyboards can develop some common problems:

• Oxidation of metal support plate
• Deterioration of springs or gum pistons
• Loss of contact sheet conductivity
• Damage to the integrated sheet due to wear or handling

Here are the recommended steps to restore this type of keyboard:

1. Remove keys – they can be removed one by one without disassembling the entire keyboard
2. Demonstrate the entire keyboard – essential to access internal elements
3. Clean gum plungers and check their elasticity
4. Check the flexible contact sheet – cleaning or replacement if necessary
5. Clean metal plate support – remove any trace of oxidation
6. Replace contact sheet – if sheet is broken or damaged

Complete catering kits are available in my shop, specially designed for these models vintage.

Available keyboard models and versions

The CPC 664 keyboard was produced in several language variants:

• AZERTY – for Francophone markets
• QWERTY – used mainly in English speaking countries

Unlike CPC 464, widely marketed under the Schneider brand in Germany and Spain, CPC 664 has remained a model exclusively Amstrad. German or Spanish versions are extremely rare, if not non-existent.

FAQ – Frequently Asked Questions about the CPC 664 Keyboard

What type of keyboard has CPC 664 ?
The CPC 664 is equipped with a keys lows using a spring + gum piston system, a flexible contact sheet with integrated sheet, and a metal support plate. This is neither the diving keyboard of CPC 464 v1, nor the flexible membrane keyboard of CPC 6128.

Can I find a replacement keyboard for the CPC 664 ?
Original keyboards are extremely rare. It is best to restore yours with specialized kits. Unfortunately, CPC 464 v2 or CPC 6128 parts are not compatible due to differences in connectivity and internal structure.

Can the CPC 664 keyboard be cleaned ?
Yes, it is possible to clean the metal support plate and gum pistons with a soft cloth and an electronic cleaner. However, the contact sheet must be replaced if it has electrical defects or a broken sheet.