Planning of the ZX Spectrum+ started in June 1984, and the machine was released in October the same year. This 48 KB Spectrum (development code-name TB) introduced a new QL-style case with an injection-moulded keyboard and a reset button. Electronically, it was identical to the previous 48 KB model. It retailed for £179.95. A DIY conversion-kit for older machines was also available. Early on, the machine outsold the rubber-key model 2:1; however, some retailers reported a failure rate of up to 30%, compared with a more usual 5-6%.