MPU-401
Encyclopedia
Musical Instrument Digital Interface
MIDI is an industry-standard protocol, first defined in 1982 by Gordon Hall, that enables electronic musical instruments , computers and other electronic equipment to communicate and synchronize with each other...
-equipped electronic music hardware to Personal Computers. It was designed by Roland Corporation
Roland Corporation
is a Japanese manufacturer of electronic musical instruments, electronic equipment and software. It was founded by Ikutaro Kakehashi in Osaka on April 18, 1972, with ¥33 million in capital. In 2005 Roland's headquarters relocated to Hamamatsu in Shizuoka Prefecture. Today it has factories in Japan,...
, which also co-authored the MIDI standard.
Design
Released around 1984, the original MPU-401 was an external breakout box providing MIDI IN/MIDI OUT/MIDI THRU/TAPE IN/TAPE OUT/MIDI SYNC connectors, for use with a separately-sold interface card/cartridge ("MPU-401 interface kit") inserted into a computer system. For this setup, the following "interface kits" were made:- MIF-APL: For the Apple IIApple IIThe Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...
. - MIF-C64: For the Commodore 64Commodore 64The Commodore 64 is an 8-bit home computer introduced by Commodore International in January 1982.Volume production started in the spring of 1982, with machines being released on to the market in August at a price of US$595...
. - MIF-FM7: For the Fujitsu FM7.
- MIF-IPC: For the IBM PCIBM PCThe IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
/IBM XT/IBM AT. - MIF-MSX: For the MSXMSXMSX was the name of a standardized home computer architecture in the 1980s conceived by Kazuhiko Nishi, then Vice-president at Microsoft Japan and Director at ASCII Corporation...
. - MIF-PC8: For the NEC PC-88NEC PC-8801The NEC PC-8801 was an early Zilog Z80-based computer exclusively released in Japan, where it became very popular, by NEC Corporation in 1981. It was informally called the "PC-88"....
. - MIF-PC98: For the NEC PC-98.
- MIF-X1: For the Sharp X1Sharp X1The X1 is a series of home computer released by Sharp Corporation from 1982 to 1988. It was based on a Z80 CPU.Despite the fact that the Computer Division of Sharp Corporation had released the MZ series, suddenly the Television Division released a new computer series called the X1...
.
The MPU-401N is an external interface, specifically designed for use with the NEC PC-98 series notebook computers. This breakout-box unit features a special COMPUTER IN port for direct connection to the computer's 110-pin expansion bus. METRONOME OUT connector was added. Released in Japan only.
Variants
Later, Roland would put most of the electronics originally found in the breakout box onto the interface card itself, thus reducing the size of the breakout box. Products released in this manner:- MPU-IPC: For the IBM PCIBM PCThe IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
/IBM XT/IBM AT and compatibles (8 bit ISA). It had a 25-pin female connector for the breakout box, even though only nine pins were used. - MPU-IPC-T: For the IBM PCIBM PCThe IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
/IBM XT/IBM AT and compatibles (8 bit ISA). The MIDI SYNC connector was removed from this Taiwanese-manufactured model, and the previously hardcoded I/O address and IRQ could be set to different values with jumpers. - MPU-IMC: For the IBM PS/2's Micro Channel ArchitectureMicro Channel architectureMicro Channel Architecture was a proprietary 16- or 32-bit parallel computer bus introduced by IBM in 1987 which was used on PS/2 and other computers through the mid 1990s.- Background :...
bus. In earlier models both I/O address and IRQ were hardcoded, in later models the IRQ could be set with a jumper. It had a 9-pin female connector for the breakout box. - S-MPU/AT (Super MPU): For the IBM AT and compatibles (16 bit ISA). It had a Mini-DIN female connector for the breakout box. The MIDI SYNC, TAPE IN, TAPE OUT, METRONOME OUT connectors was removed, but a second MIDI IN connector was added.
- S-MPU-IIAT (Super MPU II): For the IBM or compatible Plug and Play PC's (16 bit ISA). It had a Mini-DIN female connector for the breakout box with only one MIDI In and one MIDI Out connectors.
- LAPC-IRoland LAPC-IThe Roland LAPC-I is a sound card for IBM PC compatible computers produced by Roland Corporation. It basically consists of a MT-32-compatible Roland CM-32L and a MPU-401 unit, integrated onto a single full-length 8-bit ISA card. In addition to normal Roland dealers aimed at musicians, it was...
: For the IBM PCIBM PCThe IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
and compatibles. Includes the Roland CM-32L sound source. A breakout box for this card, the MCB-1, was sold separately.
- LAPC-N: For the NEC PC-98. Includes the Roland CM-32L sound source. A breakout box for this card, the MCB-2, was sold separately.
- RAP-10: For the IBM AT and compatibles (16 bit ISA). General midi sound source only. MPU-401 UART mode only. A breakout box for this card, the MCB-10, was sold separately.
- SCP-55: For the IBM and compatible laptops (PCMCIA). Includes the Roland SC-55Roland SC-55The Roland SC-55 is a GS MIDI synthesizer sound module released in 1991 by Roland. The SC-55 was the first sound module to incorporate the new General MIDI standard....
sound source. A breakout box for this card, the MCB-3, was sold separately.
Still later, Roland would get rid of the breakout box completely and put all connectors on the back of the interface card itself. Products released in this manner:
- MPU-APL: For the Apple IIApple IIThe Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...
series. Single-card combination of the MIF-APL interface and MPU-401, featuring MIDI IN, OUT, and SYNC connectors. - MPU-401/AT: For IBM AT and compatibles. Includes a connector for Wavetable daughterboards.
- MPU-PC98: For the NEC PC-98.
- MPU-PC98II: For the NEC PC-98.
- S-MPU/PC (Super MPU PC-98): For the NEC PC-98.
- S-MPU/2N (Super MPU II N): For the NEC PC-98.
- SCC-1: For the IBM PCIBM PCThe IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
and compatibles. Includes the Roland SC-55Roland SC-55The Roland SC-55 is a GS MIDI synthesizer sound module released in 1991 by Roland. The SC-55 was the first sound module to incorporate the new General MIDI standard....
sound source.
Modes
The MPU-401 can work in two modes, normal mode and UART mode. "Normal mode" would provide the host system with an 8-track sequencer, MIDI clock output, SYNC 24 signal output, Tape Sync and a metronome; as a result of these features, it is often called "intelligent mode". Compare this to UART mode, which reduces the MPU-401 to simply relaying in-/outcoming MIDI data bytes.With computers becoming more powerful, the features offered in "intelligent mode" have become obsolete, as implementing them in the host system's software became more efficient (than paying for dedicated hardware that will do them). As a result, the UART mode became the dominant mode of operation, with many clones not supporting the "intelligent mode" at all, being advertised as MPU-401 compatible.
Contemporary interfaces
Physical MIDI connections are increasingly replaced with the USB interface, and a USB to MIDI converter in order to drive musical peripherals which do not yet have their own USB ports. Often, peripherals are able to accept MIDI input through USB and route it to the traditional DIN connectorDIN connector
A DIN connector is a connector that was originally standardized by the , the German national standards organization. There are DIN standards for a large number of different connectors, therefore the term "DIN connector" alone does not unambiguously identify any particular type of connector unless...
s. MPU-401 support is no longer included in Windows Vista
Windows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
, but is still supported by Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
and Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
.