Jazz

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Jazz was the codename under which this family of systems was originally developed by Microsoft before it was sold off to MIPS Computer Systems, Inc. MIPS, Toshiba, Acer and various customers and licenses have developed a variety of architecturally very similar systems.

History

Most of these systems shipped with the ARC firmware and were intended to run Windows NT. Some systems made by MIPS (i.e., the MIPS Magnum 4000PC and 4000SC) were reconfigurable to run in big endian mode by reflashing the firmware EEPROM with MIPS, Inc.'s proprietary SASH firmware; in big endian mode the Magnums could run RISC/os, which was MIPS, Inc.'s proprietary BSD-derived UNIX variant.

Architecture

All Jazz computers share the same "core" architecture codenamed RC4030 or MCTADR (after the motherboard ASIC chipset). This includes, inter alia:

  • an RC4030 DMA controller;
  • an RC4030 IRQ controller (see also Linux_Interrupts); and
  • an RC4030 Timer.

Some Jazz models use additional i8259 (PC-style IRQ) and i8257A (PC-style DMA) controllers to support ISA/EISA bus IRQ/DMA.

SCSI Options

The ACER PICA-61,Olivetti M700-10, MIPS Magnum 4000 and MIPS Millenium have a SCSI interface based on the NCR 53C90 chipset (also known as the QLogic ESP216 or ASC, Advanced SCSI Controller).

Networking Options

The ACER PICA-61,Olivetti M700-10, MIPS Magnum 4000 and MIPS Millenium all use a SONIC Ethernet chip.

Video Options

The original Microsoft/MIPS Magnum 4000 and Olivetti M700-10 use a simple framebuffer (capable of resolutions of 1024x768, 1200x968, or 1280x1024 pixels at 8 bpp color.) based on the Inmos G300 or G364 (64-bit) RAMDAC and VRAM chipset (a similar G364-based framebuffer is found in an aftermarket graphics card for the Amiga). The resolution and sync rate are fixed, and apparently can only be changed by reprogramming the EPROM installed on the framebuffer.

The Magnum framebuffer is equipped with a DB13W3-F connector that appears to be wired similarly to SGI devices of the same era (rather than Sun devices), and it can be adapted to output to a modern flat panel display. One option is to acquire a cheap Sun style 13W3 to VGA adapter (less than USD $10 on eBay, etc) and use a pair of narrow wire nippers to clip out all 13 smaller pins, leaving just the 3 coaxial connectors. In this configuration, the framebuffer will output the sync signals on the green signal wire. Almost all modern flat panel displays are capable of displaying a sync-on-green video signal, though some of them will display an image with a slightly green tint. Since 4x3 aspect ratio displays are currently considered obsolete, it should be fairly economical to acquire a good quality 1280x1024 flat panel.

It is also possible to hard-wire a DB15HD-F VGA style connector to the back of the framebuffer, supplying separate signal wires for hsync and vsync. csync is not provided by the Magnum framebuffer. Diagrams specifying how to connect a VGA port to an SGI Indy's Newport graphics are applicable to the Magnum framebuffer

It appears that the Magnum framebuffer's video signal is likely to be compatible with any device advertised as being compatible with the output of an SGI Indy with Newport graphics.

Some Magnum computers were configured with a "Jaguar" framebuffer which has a VGA compatible DB15HD port rather than a 13W3. This framebuffer has some 2D acceleration but is unfortunately only compatible with Windows NT.

The ACER PICA-61 uses an S3 968 SVGA videocard with 2MB of video memory on the custom fast PICA bus. The video card looks like an EISA card but the notch is on the wrong side.

The NEC Evolution uses a Cirrus Logic based video.

Sound options

The Microsoft/MIPS Magnum 4000 includes a simple sound controller (codename Jazz) comprising two DMAs—one for each of the left and right channels, respectively.

Although largely identical to the Magnum 4000 series in other respects, the Olivetti M700-10 nonetheless uses AD1815-based sound controller (?need to check) rather than the simple DMA system of the Magnum.

I/O options

All Jazz computers are using PC-style i8042 keyboard and PS/2 mouse controller, i8072 floppy controller (attached to the RC4030 DMA and IRQ), 2x16450 RS-232 serial ports and PC-style LPT.

Firmware

It is possibly to reconfigure MIPS Magnum R4000 system from little- to big-endian and vice versa by loading ARC or MIPS Monitor into the Magnum's FLASH memory.

All Jazz family systems come with an ARC firmware.

Linux Support

Linux/MIPS has supported the Olivetti M700-10 almost since the original release of the M700, with support for the quite similar MIPS Magnum R4000PC achieved soon thereafter. Support for the Jazz machines is reportedly stable in the 2.2 kernels, but suffers from various degrees of bitrot after that. As of Linux 2.6 resurrection of support is being worked on. No test results on other Jazz family systems are available.

External Links

  • NetBSD port to ARC machines
  • OpenBSD port to ARC machines
  • GXemul has rudimentary support for the Jazz architecture
  • MIPS Magnum entry at Wikipedia
  • Jazz entry at Wikipedia
  • Sensi.org Anecdotal history of the Mips Magnum from usenet