be connected to the Interface 1 by daisy chaining one drive to the next via an electrical connector block. The system acquired a reputation for unreliability. The tapes stretched during use (giving them a short life span), eventually rendering the data stored unreadable. Also the "write protection" was software-based, thus a computer crash could erase the data on an entire tape in 8 seconds. The cartridges were relatively expensive (initially sold for £4.95 each, later reduced to £1.99). Later uses Microdrives were also used as the native storage medium of the Sinclair QL, which incorporated two internal drives. These were very similar to the ZX Microdrive, but used a different logical format, allowing each cartridge to hold at least 100 kB. Mechanically the drives were similar, however, they ran slightly slower and had a take-up acceleration start instead of the instant start of the ZX Spectrum drives, putting less strain on the cartridges. The QL also included a Microdrive expansion bus, allowing the attachment of up to six external QL Microdrives. These were never produced, probably due to lack of demand. It was, however, possible to connect ZX Microdrives to a QL by putting a twist in the cable. In addition to the QL versions, dual internal Microdrives were included in the related ICL One Per Desk system (also badged as the Merlin Tonto and Telecom Australia Computerphone). These drives were re-engineered by ICL for greater reliability, and used a format incompatible with both ZX and QL Microdrives. See also Stringy floppy Rotronics Wafadrive References External links ZX Microdrive information at Planet Sinclair Sinclair User, April 1985, News section Computer storage devices Home computer peripherals Sinclair Research Computer-related introductions in 1983