TR-DOS

{{Short description|Disk operating system for the ZX Spectrum}}

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| name = TR-DOS

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| developer = Technology Research Ltd

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| released = {{Start date and age|1984}}

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| latest release version = 5.03

| latest release date = {{Start date and age|1986}}

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| language = English

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| supported platforms = ZX Spectrum

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TR-DOS is a disk operating system for the ZX Spectrum with Beta Disc and Beta 128 disc interfaces. TR-DOS and Beta disc were developed by Technology Research Ltd (UK), in 1984.{{cite web|url=http://www.worldofspectrum.org/infoseekid.cgi?id=1000034|title=Beta Disk Interface - World of Spectrum|website=Worldofspectrum.org|accessdate=9 December 2018}}{{cite book|url=https://books.google.com/books?id=4yG4AwAAQBAJ&q=Technology+Research+Ltd+tr-dos+-wikipedia&pg=PA78|title=The ZX Spectrum on Your PC|first=Colin|last=Woodcock|date=7 May 2012 |publisher=Lulu.com |isbn=9781471696121|accessdate=9 December 2018|via=Google Books}} A clone of this interface is also used in the Russian Pentagon and Scorpion machines.

It became a standard in Russia and most disk releases for the ZX Spectrum, especially of modern programs, are made for TR-DOS as opposed to other disk systems.{{Cite news |last=Woodcock |first=Colin |date=December 2003 |title=TR-DOS |work=ZXF |issue=6 |url=https://sites.google.com/site/zxfmagazine/storage23}}{{cite web |last1=Pavlov |first1=Paul |last2=Striker |date=2022 |title=Virtual TR-DOS |url=https://vtrd.in/ |accessdate=9 December 2018 |website=Virtual TR-DOS}}

The latest official firmware version is 5.03 (1986).{{Cite book |url=http://z00m.speccy.cz/docs/betadisk.txt |title=Technology Research BETA 128 Disk Interface - User Manual |publisher=Technology Research Ltd |year=1986|archive-url=https://web.archive.org/web/20160923142910/http://z00m.speccy.cz/docs/betadisk.txt |archive-date=2016-09-23 }}

Unofficial versions with various enhancements and bug-fixes have been released since 1990, with the latest being 6.10E (2006).{{Cite web |title=Customized ROM |url=http://zxspectrum.it.omegahg.com/_TR.htm |url-status=dead |archive-url=https://web.archive.org/web/20160918231824/http://zxspectrum.it.omegahg.com/_TR.htm |archive-date=2016-09-18 |access-date=2016-08-19 |website=speccy4ever}}

TR-DOS handles SS/DS, SD/DD floppy disks. All modern versions support RAM Disk and some versions support hard disks.

Current emulators support TR-DOS disk images in the formats .TRD or .SCL.