Editing Mazovia encoding (section)

{{Short description|Encoding used under DOS to represent Polish texts}}
{{Use dmy dates|date=December 2019|cs1-dates=y}}
{{infobox character encoding
| name = Mazovia encoding
| kermit = MAZOVIA
| alias = cp667, cp790, cp991, MAZ
| lang = [[Polish language|Polish]]
| basedon = [[OEM-US]]
| classification = [[Extended ASCII]], [[OEM code page]]
| otherrelated = Fidonet Mazovia (MFD),<br/>Mazovia 157,<br/>FreeDOS-991
}}
{{Redir|CP790|the printer|Canon SELPHY CP790}}
'''Mazovia encoding''' is a character set used under [[DOS]] to represent [[Polish language|Polish]] text. The character set derives from [[code page 437]], with specific positions modified to accommodate Polish letters. Notably, the Mazovia encoding maintains the block graphic characters from code page 437, distinguishing it from [[IBM]]'s later official Central European code page 852, which failed to preserve all block graphics, leading to incorrect display in programs such as Norton Commander.

The Mazovia encoding was designed in 1984 by Jan Klimowicz of {{Interlanguage link multi|Instytut Maszyn Matematycznych{{!}}IMM|pl|3=Instytut Maszyn Matematycznych}}. It was designed as part of a project to develop and produce a Polish IBM PC clone codenamed "{{Interlanguage link multi|Mazovia 1016|pl}}". The code page was specifically optimized for the peripheral devices commonly used with the Mazovia 1016 computer, including a graphics card with dual switchable graphics, a keyboard with US English and Russian layouts, and printers with Polish fonts. The Mazovia encoding gained widespread acceptance and distribution in Poland when the [[Polish National Bank]] (NBP) adopted it as a standard in 1986. The NBP played a significant role in facilitating the production of compatible computers by Ipaco, which utilized Taiwanese components under the guidance of {{Interlanguage link multi|Zbigniew Jakubas|pl}} and Krzysztof Sochacki.

Some ambiguity exists in the official code page assignment for the Mazovia encoding:

[[PTS-DOS]] and [[S/DOS]] support this encoding under code page 667 (CP667).<ref name="Paul_2001_NECPINW"/> The same encoding was also called code page 991 (CP991) in some Polish software,<ref group="nb" name="NB_PLC"/><!-- The actual origin of the CP991 assignment is still unknown, but PLC shows that it must have existed before 1997. The PLC variant of CP991 seems to be identical to what PTS-DOS under codepage 667 and NEC supported in their Pinwriters as "Mazovia". PTS-DOS codepage 667 and the NEC font are known to be identical to the later code page 790, as supported by FreeDOS. The FreeDOS variant of CP991, however, seems to be incompatible with the original definition of CP991, but this needs to be verified. --> however, the FreeDOS implementation of code page 991 seems not to be identical to this original encoding.
The DOS code page switching file <code>NECPINW.CPI</code> for [[NEC Pinwriter]]s supports the Mazovia encoding under both code pages 667 and 991.<!-- the 790 assignment did not exist as this time --><ref name="Paul_2001_NECPINW"/> FreeDOS has meanwhile introduced support for a variant of the Mazovia encoding under code page 790 (CP790) as well. The [[Fujitsu]] ''DL6400 (Pro)'' / ''DL6600 (Pro)'' printers support the Mazovia encoding as well.<ref name="Fujitsu_1994_DL6400_DL6600"/> This encoding is known as '''code page 3843''' in [[Star Micronics|Star]] printers.