Casia Tyzack VSD
This page was last modified 21:41, 17 January 2021 by Mars2000you. Based on work by Rderooy.



The Casia Tyzack VSD was constructed between 1989 and 1992 by the Dutch company Casia. It is basically a combination of a modified Philips VG-8230 MSX2 enhanced to MSX2+ and used as main computer with 5 other computers:

It was also planned to use a Philips VG-8020 MSX1 as sequencer.

CP/M 2.2 is used on the Philips P2000C to initialize the sampler before loading the Tymos Operating System from the main computer.

The Philips VG-8230 is enhanced with MSX2+ VDP, MSX-DOS 2 rom, a rom with the Tymos OS including Tymos BASIC and another rom with the TyzackVSD BASIC extensions. The RAM is upgraded to 256kB, a 20Mb SCSI harddisk is built-in and a writable at boot 16kB SRAM is included, allowing loading of the Tymos OS and easy updates of the system.

A little rom added to the Toshiba HX-10P is used during the boot sequence to initialize the subsystem.

Besides, this transputer system has

  • a improved homebrew digitizer with a resolution of 256 x 256 pixels and 32 shades of gray (addition of 3-bit A/D to handle the 19268 MSX2+ colors)
  • two stereo Philips SAA1099 sound generators with 6 channels per generator - for info about the internal registers, see the instruction CMD SND of Tyzack64M BASIC
  • a General Instrument SPO256-AL2 speech synthesizer (64 phonems)
  • a homebrew stereo AD/DA sampler, with its own RAM (partly inspired by the Doepfer/Elektor sampler, though much less sophisticated)
  • a homebrew A/D interface for printer scanner
  • a MIDI interface (AY-3-1015 UART)
  • an RS-232C interface

VSD stands voor Veel Snel Duur, what means Much Fast Expensive.

The following table does not includes the Philips VG-8020 as it was only planned and the Casia team does not have found trace of it in his archive.

Brand Casia
Model Tyzack VSD
Year 1989 to 1992
Region the Netherlands
Launch price
RAM 2076kB : 256kB (Philips VG-8230) + 16kB (SRAM) + 128kB (Sony HB-F9P) + 64kB (Toshiba HX-10P) + 64kB (Philips P2000C) + 512kB (Tulip System 1) + 12kB (Acorn Atom) + 1024kB (sampler RAM)
VRAM 304kB : 128kB (Philips VG-8230)) + 128kB (Sony HB-F9P) + 16kB (Toshiba HX-10P) + 32kB (Philips P2000C)
Media MSX cartridges, 3.5" 1DD floppy disks (Philips VG-8230) + 5.25" floppy disks (Philips P2000C and Tulip System 1)
Video Yamaha V9958 (enhanced Philips VG-8230) + Yamaha V9938 (Sony HB-F9P) + Texas Instruments TMS9929A (Toshiba HX-10P) + Motorola 6845 (Philips P2000C and Tulip System 1) + NEC 7220 coprocessor (Tulip System 1) + Motorola 6847 (Acorn Atom)
Audio PSG (custom chip integrated in MSX-Engine S3527) (Philips VG-8230) + PSG (YM2149 integrated in MSX-Engine S1985) (Sony HB-F9P) + PSG (AY-3-8910A) (Toshiba HX-10P) + speaker 1 channel (Acorn Atom)
Chipset Yamaha S3527 (Philips VG-8230) + Yamaha S1985 (Sony HB-F9P) + Toshiba TCX-1007 (Toshiba HX-10P)
Keyboard layout {{{keylayout}}}
Extras internal 20MB hard disk drive, built-in MSX-DOS 2, two stereo Philips SAA1099 sound generators, General Instrument SPO256-AL2 speech synthesizer, stereo AD/DA sampler, digitizer with 3-bit A/D, A/D interface for printer scanner, interface for music keyboard, MIDI interface, RS-232C interface, Tymos Operating System with Tymos BASIC, TyzackVSD BASIC, reset button
Emulation not applicable


Casia Tyzack VSD - Main box + Sony HB-F9P keyboard
Casia Tyzack VSD - Sub box
Casia Tyzack VSD - Inside of sub box
Casia Tyzack VSD
Main PCB (Philips VG-8230)
Casia Tyzack VSD - Toshiba HX-10P PCB
Casia Tyzack VSD - Sampler I/O PCB
Casia Tyzack VSD - Inside of main box = Philips VG-8230 + Toshiba HX-10P
Casia Tyzack VSD - Digitizer
Casia Tyzack VSD - Main I/O and Speech Synthesizer


Main system

The Philips VG-8230 is an MSX2 with a Z80 from Zilog (Z8400APS) and the MSX-Engine S3527 from Yamaha. It is enhanced with the MSX2+ VDP.

Digitizer subsystem

The Sony HB-F9P is an MSX2 with a Z80A from Sharp (LH0080A) or NEC (uPD780C) and an S1985 MSX-Engine from Yamaha.

48T music keyboard control and MIDI subsystem

The Toshiba HX-10P is an MSX1 with a Z80A from Sharp (LH-0080A).

Sequencer subsystem (as it was planned)

The Philips VG-8020/00 is an MSX1 with a Z80 from NEC (D780C-1) without MSX Engine. The other revisions have a Z80 from NEC (D780C-1) or Zilog (Z8400APS) and the MSX-Engine S3527 from Yamaha.

Sampler subsystem

The Philips P2000C is a 8bit computer with two Z80A (the second is dedicated to I/O) running at 4 MHz.

Number cruncher and word processing subsystem

The Tulip System 1 is a 16bit computer based on the Intel 8086 running at 8 MHz. Its VDP is based on the Motorola 6845 and there's also a built-in NEC 7220 video display coprocessor.

Drums ans synchronicity subsystem

The Acorn Atom is a 8bit computer with a MOS Technology 6502 clocked at 1MHz.


  • RF output
  • RGB output (8-pin DIN)
  • Monitor connectors
  • Audio output connectors
  • Audio input connector
  • Video input connector
  • Keyboard connector
  • Tape recorder connector
  • RS-232C connectors
  • MIDI connectors
  • Connector for music/sampler keyboard
  • Centronics compatible Parallel port for a printer
  • 2 general connectors (joysticks, mouse, paddle controllers, ...)
  • 2 cartridge slots
  • 220V AC Power socket