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MSX turbo R

Panasonic's MSX turbo R integrated dual processors and battery-backed SRAM, distinguishing itself within the MSX standard through hybrid architecture and embedded Japanese text support.

Msx msx-turbo-r, archival photo
Photo: Jeff Keyzer from Austin, TX, USA, CC BY-SA 2.0, via Wikimedia Commons. source

The MSX turbo R, manufactured by Panasonic, represents a technical departure within the MSX family by incorporating two microprocessors: a Z80 and an R8001113. The R800 is explicitly described as Z80-compatible but augmented with additional instructions, enabling enhanced performance while maintaining backward compatibility1113. These processors are linked to system memory and peripherals via a custom bus controller, the 51990, which serves as the architectural core of the machine1113.

The 51990 is more than a bridge. It integrates a PCM controller for audio sampling and recording, a feature directly accessible through the MSX turbo R PCM port11131214. This port, along with the Philips NMS1205 muziekmodule, operates at 8-bit resolution1214. However, the system includes a built-in low-pass filter that affects audio output, reportedly producing "platte" (flat) sounds in some applications1214. Despite this limitation, the PCM port was assessed as "goed bruikbaar" (well usable) for its intended purposes1214.

Memory architecture includes a minimum of 256 kB of main RAM and a separate 16 kB SRAM unit connected to a battery, preserving data when powered off1113. This SRAM is shared between built-in software and the kanji processor, which supports user-defined character combinations using the JIS 1 and JIS 2 kanji ROMs, integral to handling Japanese text1113. The presence of these ROMs reflects the system’s design focus on Japanese language processing1113.

Additional integrated components include an FM-PAC sound module and a "2+ video chip," though the exact capabilities and specifications of the latter remain undocumented in the source material1113. The system ships with MSXDOS 2, providing disk-based operating functionality1113. Panasonic also included proprietary built-in software, which, while not part of the MSX turbo R standard, uses the battery-backed SRAM for persistent data storage1113.

Two model variants are identified by type numbers AIST and AICT, referred to in documentation as ST and CT1113. The machine held a niche position in certain markets; in the Netherlands, for example, ownership was limited, contributing to challenges in software support1214. This scarcity was notable enough that developers of the GFX 9000 graphics cartridge initially targeted the Turbo R exclusively, though later lamented its limited install base34. One contemporary observation noted wryly that "mensen met een gewone MSX 2 nu zitten te gniffelen" (people with a regular MSX 2 are now snickering), highlighting the Turbo R’s underperformance in market penetration despite its technical ambitions34.

References

  1. msx computer club magazine 88
  2. msx computer magazine 88 voorjaar 1997 (1997)
  3. msx computer club magazine 82
  4. msx computer magazine 82 mrt apr 1996 (1996)
  5. 1985 07 BYTE 10-07 Computers and Space (1985)
  6. 1985 05 Dr Dobbs Journal (1985)
  7. 1985 05 Dr Dobbs Journal (1985)
  8. profiles v2n10
  9. msx computer magazine 42 nov 1990 (1990)
  10. msx computer magazine 42
  11. msx computer club magazine 73
  12. msx computer club magazine 86
  13. msx computer magazine 73 feb 1995 (1995)
  14. msx computer magazine 86 nov dec 1996 (1996)
  15. msx computer magazine 03
  16. msx computer magazine 03 jul aug 1985 (1985)