Editing MSX (section)

==Peripherals==
[[File:MSX Computer Color Limit.gif|thumb|The effect of [[attribute clash]] when using the 256×192 high-resolution mode on MSX-1. To avoid it, the [[TMS9918]] provides up to 32 sprites that can be superimposed over the main graphic screen.]]
[[File:Panasonic FS-A1WSX 20060731.jpg|thumb|MSX2+ computer: a [[Panasonic]] FS-A1WSX]]

===Keyboard===
The keyboard is a functionally separate unit which could be connected by non-multiplexed and [[Multiplexing|multiplexed]] interfaces. Multiplexed keyboard units feature additional data direction line, allowing sending scan line number to the keyboard using same data lines used for return scan code, decreasing overall number of wires between keyboard and machine. Non-multiplexed interface is usually used for internal keyboards (and some external keyboards, like Panasonic CF-3300); multiplexed interface is used for external keyboards (e.g. in Yamaha YIS805 model).

The keyboard is organized as a [[Keyboard matrix circuit|matrix]] with maximum 11 input lines and 8 output lines, accounting for maximum 88 keys (including all control, numerical and alphanumerical keys). Each scan line is regularly queried to identify the state of the keys on the line; query speed is identified by the system interrupt frequency. Such organization allows system to sense state of each key, not exhibiting notorious problem with 8042 [[microcontroller]]-based keyboards when pressing several keys simultaneously (usually more than 3) generates wrong input characters, or renders inability to sense the press of more keys.

Due to the keyboard scan being controlled by the system interrupts, one of the troubleshooting hints when an MSX machine does not display any image (assuming power is present) is to press the CAPS key to see if the respective LED toggles. If it does not toggle, the system is likely suffering a more serious problem than just lack of image on the screen (i.e. the problem with video cable or video display interface in overall).

In 2009, Kamil Karimov designed the adapter board<ref>{{Cite web |last=Karimov |first=Kamil |date=2010-02-14 |title=Контроллер PS/2 клавиатуры для MSX (Russian) |url=http://www.msx.org/node/35495?page=2#comment-187005 |url-status=live |archive-url=https://web.archive.org/web/20161222153606/https://www.msx.org/node/35495?page=2#comment-187005 |archive-date=December 22, 2016 |access-date=2013-09-20 |publisher=MSX Resource Center}}</ref> to connect a PS/2 keyboard to the multiplexed MSX keyboard interface. The firmware embedded into its [[Atmel AVR|ATTiny]] chip was tailored for Daewoo CPC machines.

In 2011, AGE Labs embedded a PS/2 keyboard controller unit, based on [[Microchip]] microcontroller, into its [[GR8BIT]] do-it-yourself machine. Its firmware is developed to directly convert PS/2 scan codes to the MSX keyboard scan codes. Thus it is fully transparent to the applications, allowing use of the controller unit with different MSX-compatible machines and for different localization setups.<ref name="language-pack" />

===Cartridges===
MSX standard requires at least 1 cartridge slot, most MSX models have 2. These slots<ref>{{Cite web |title=2 standard MSX cartridge slots |url=http://www.auroramsx.nl/gallery/Yamaha/02.jpg |url-status=dead |archive-url=https://web.archive.org/web/20120426051655/http://www.auroramsx.nl/gallery/Yamaha/02.jpg |archive-date=2012-04-26}}</ref> are interchangeable, so in most cases it makes no difference in which slot a cartridge is inserted. The physical connector is a 50 pin (2 × 25 contacts), standard 2.54&nbsp;mm (0.1 inch) pitch [[edge connector]]. Using these cartridge slots, a wide variety of peripherals could be connected.

Regular game cartridges are about the size of an [[cassette tape|audio cassette]] (so-called "Konami size"). Despite their higher cost, this was a popular format due to its reliability and ease of use.

Around 1985, [[Hudson Soft]] released the credit card-sized [[Bee Card (game cartridge)|Bee Card]], which was meant as a cheaper and more convenient alternative to ROM cartridges. But it was a commercial failure, and very few titles were released on the format.

Source files<ref>{{Cite web |title=MSX breadboard schematic, board and library |url=http://www.gr8bit.ru/downloads/msx-breadboards.zip |url-status=dead |archive-url=https://web.archive.org/web/20131201000000/http://www.gr8bit.ru/downloads/msx-breadboards.zip |archive-date=1 December 2013 |access-date=23 June 2013 |website=AGE Labs}}</ref> for development of the MSX cartridges are available from AGE Labs for [[EAGLE (program)|EAGLE]].

===Floppy disk drives===
Early MSX models did not have a built-in disk drive, so software were initially published on cartridge and cassette tape.<ref name="dvorakmsx" />

Mitsumi [[QuickDisk]]s were originally launched as a proprietary extension for the MSX in early 1984,<ref>[https://www.msx.org/wiki/Category:QuickDisk_BASIC Category:QuickDisk BASIC - MSX Wiki] {{Webarchive|url=https://web.archive.org/web/20230223234854/https://www.msx.org/wiki/Category:QuickDisk_BASIC|date=February 23, 2023}} Mitsumi QuickDisk BASIC Copyright screen</ref> but they never really caught on, as they were quickly surpassed by the standard floppy disk interface released a few months later. Only a handful of titles were released in this format.

Sony also created a battery backed RAM cartridge the [[HBI-55]] "data cartridge" in 1984 for some computers in their "Hit-Bit" line of MSX systems, that could be used to store programs or data as an alternative to cassette tapes.<ref>[http://www.clive.nl/retro-computer-hardware/data-cartridge-hbi-55-sony-hit-bit-4k-bytes picture of HBI-55 data cartridge] {{webarchive|url=https://web.archive.org/web/20131029062026/http://www.clive.nl/retro-computer-hardware/data-cartridge-hbi-55-sony-hit-bit-4k-bytes |date=2013-10-29 }}</ref> Many Yamaha Music software are also compatible with this cartridge.

Traditional [[floppy disk]] drives were made available for MSX in 1984, either built-in or in the form of a cartridge containing the disk interface electronics and a BIOS extension ROM (the floppy disk drive interface), connected to an external case with the drive. In South America, many of these systems used a {{convert|5.25|in|mm|abbr=on}} floppy disk drive, but in Europe, {{convert|3.5|in|mm|abbr=on}} drives were more popular. In Japan, some MSX1 systems included a built-in 3.5-inch disk drive, like the Panasonic (previously named National) CF-3300. In Europe, a range of Philips MSX2 systems NMS 8230, 8235, 8245, 8250 and above featured either 360 or 720&nbsp;KB 3.5-inch floppy drives.

In 1985, the MSX2 was released, and these systems often (but not always) also included a built-in 3.5-inch disk drive. Consequently, the popular media for games and other software shifted to floppy disks.

The [[MSX-DOS]] [[disk operating system]] had [[binary code compatibility|binary compatibility]] with [[CP/M]], but used the same [[file allocation table|FAT]] [[file system]] as [[MS-DOS]]. Its user commands were also similar to early MS-DOS versions. In this way, Microsoft could promote MSX for home use while promoting [[MS-DOS]] based [[personal computer]]s in office environments.<ref>{{Cite web|url=https://archive.org/details/MSXTechnicalDataBook|title=MSX Technical Data Book|date=May 12, 1984|via=Internet Archive}}</ref>

The MSX 3.5-inch floppy disks are directly compatible with MS-DOS (although some details like [[Undeletion|file undeletion]] and [[boot sector]] code were different). Like MS-DOS&nbsp;1, MSX disks (formatted) under MSX-DOS&nbsp;1 have no support for [[subdirectories]].<ref>{{Cite web |title=MSX-DOS 2 section |url=http://www.faq.msxnet.org/dos2.html |url-status=live |archive-url=https://web.archive.org/web/20190812050348/http://www.faq.msxnet.org/dos2.html |archive-date=August 12, 2019 |access-date=2011-06-22 |website=The Ultimate MSX FAQ |publisher=Faq.msxnet.org}}</ref>

In September 2012, AGE Labs extended the standard by including support for 1.44Mb 3.5-inch format. The 1.44Mb diskette size goes in two configurations: Standard (1 sector per cluster, 9 FAT sectors), and Compatible (4 sectors per cluster, 3 FAT sectors).<ref>{{Cite web |title=Storage subsystem v.3.0 Manual |url=http://www.gr8bit.ru/GR8BIT-Knowledge-Base/GR8BIT-DN0003-Storage-subsystem-v-3-0-Manual.pdf |url-status=live |archive-url=https://web.archive.org/web/20131109214406/http://www.gr8bit.ru/GR8BIT-Knowledge-Base/GR8BIT-DN0003-Storage-subsystem-v-3-0-Manual.pdf |archive-date=November 9, 2013 |access-date=23 June 2013 |website=AGE Labs}}</ref>

===MSX-Audio===
* [[Yamaha Y8950]], commercially released as:
** Panasonic: MSX-Audio FS-CA1 (32&nbsp;KB of SampleRAM, 32&nbsp;KB of AudioROM)
** Philips: [[Philips NMS-1205|Music Module NMS-1205]] (32&nbsp;KB of SampleRAM, no MSX-Audio BIOS)
** Toshiba: MSX FM-synthesizer Unit HX-MU900 (no sample RAM, no MSX-Audio BIOS)
* 9 channels [[Frequency modulation synthesis|FM]] or 6 channels FM + 5 drums. YM3526 compatible.
* [[ADPCM]] record and play, with [[Hardware acceleration]]
* Can be upgraded to 256&nbsp;KB of SampleRAM

===MSX-Music===
* [[Yamaha YM2413|Yamaha YM2413 (OPLL)]], also known as:
** MSX-Music (standard name)
** [[Panasonic]]: FM-PAC
** [[Zemina]]: Music Box
** Checkmark: FM-Stereo-Pak
** DDX: FMX
** Tecnobytes: FM Sound Stereo (contains the compatible U3567 chip)
* 9 channels [[Frequency modulation synthesis|FM]] or 6 channels FM + 5 drums
* 15 pre-set instruments, 1 custom
* Built-in on most MSX2+ and as standard on MSX TurboR computers