Sanyo PHC-77
This page was last modified 13:37, 24 May 2023 by Mars2000you. Based on work by Gdx and Msxholder and others.




The Sanyo PHC-77, a.k.a Wavy77, is a "Word-pro PersoCom" (Word processor Personal Computer) with a built-in 24 dots thermal transfer printer and an FDD drive.

The PHC-77 was aimed at the Japanese market and available in one color but depending the serie it is more or less black, or dark brown.

A special edition was released by the Com Intex (= Computer Communication Inter Exchange) company in a monstruous educational box containing the computer and 20 floppy disks with 85 lessons (was also sold in a set with the MSX2 National FS-4600F, Sanyo MPC-25FS and the MSX2+ Panasonic FS-A1WX).

The keyboard can be folded onto the unit for storage or travel. A wheel on the right side allow to change the print density.

The printer part includes two roms, 16kB for the control of the printer and 256kB for printing of Kanji characters.

The original replacement ink cartridge is the SWP-MR.

This model uses a c7 power connector this is unusual for a non European device. It is 100 Volt.

Size opened: 440×352×100 (WxLxH)
Size folded: 440×210×125 (WxLxH)
Weight: 4.7kg

Brand Sanyo
Model PHC-77
Year 1987
Region Japan
Launch price ¥138,000
RAM 64kB (in slot 3-3)
VRAM 128kB
Media MSX cartridges, 2DD floppy disks
Video Yamaha V9938
Audio PSG (YM2149 integrated in MSX-Engine S1985)
Chipset Yamaha S1985
Keyboard layout QWERTY/JP50on + numeric keypad
Extras 720kB 3,5" floppy disk drive, MSX-JE (ASCII Japanese MSX-Write including Kanji-ROM level 1), computer reset button, built-in printer, printer reset button, wheel for selecting print density, folding keyboard, switch for enabling/disabling the firmware, MSX-DOS 1 and Wavy Note on 2 floppy disks
Emulation ROMs dumped and emulated with exception of the internal printer. The firmware application menu switch is enabled by default and cannot be changed. Dump of floppy disks is still needed.


This computer comes with a built-in Japanese Word Processor with kana-kanji conversion, MSX-Write, that ASCII had released in 1986 as apart cartridge and includes a Kanji-ROM level 1. It's actually the first version of the MSX-JE system.

This Word Processor seems to have been created by Yamaha, as the indication "YAMAHA-MSX-JWP-SYSTEM" appears at three different locations of the rom.

The firmware is automatically launched when you boot the machine, but you can bypass it by changing the position of the front switch before booting the computer. Note however that on emulators, this switch is not yet emulated.

The firmware menu has 3 options:

  • Access to the Word Processor
  • Settings - you can choose to work in MSX(1) mode -15 characters- or MSX2 mode -30 characters- and 3 different layouts are available
  • Access to MSX-BASIC

MSX-Write does not have a SRAM. Savings need to be done on disk, tape or (temporary) memory disk.

Floppy disks

Two floppy disks were provided with this computer:

- the first disk contains MSX-DOS1 and access to MSX-Write

- the second disk contains Wavy Note with 6 applications: Clock - Calendar - Memo - Address - Schedule - Calculator



Note: MSX-Write is integrated on the printer board. The pictures of the cartridge PCB v.1 and v.2 are available below to make easy a comparison.

Sanyo PHC-77 dark brown
MSX-Write PCB v.1
MSX-Write PCB v.2
Sanyo PHC-77 dark black
Sanyo PHC-77 back
Sanyo PHC-77 right side
Sanyo PHC-77 box
Sanyo PHC-77 folded
Sanyo PHC-77 black/gray
Sanyo PHC-77 unit, manuals and Wavy Note floppy disk
Sanyo PHC-77 label
PHC-77 manual and floppy disks
Sanyo PHC-77 floppy disks
Sanyo PHC-77 mainboard
Sanyo PHC-77 printer board
Sanyo PHC-77 - Com Intex box
PHC-77 Com intex package
Sanyo PHC-77 with Com Intex disks


MSX-Write Intro screen
MSX-Write Menu
MSX-Write Settings
MSX-Write Word Processor MSX2 mode layout 1
MSX-Write Word Processor MSX2 mode layout 2
MSX-Write Word Processor MSX2 mode layout 3
MSX-Write Work screen after pressing on ESC
MSX-Write Word Processor MSX1 mode


Wavy Note Menu


The PHC-77 is an MSX2 with two Z80A from Sharp (LH0080A), a MSX-Engine S1985 from Yamaha and a Gate Array chip M60011 from Mitsubishi. The floppy disk controller is the MB8877A from Fujitsu Microelectronics.

The floppy disk drive made by Toshiba doesn't require rubber belt. The second Z80A is used by the printer.

The cartridge slots and general connectors (for joystick, mouse, etc...) are on the printer board, not on the mainboard.

Slot Map

Slot 0 Slot 1 Slot 2 3-0 3-1 3-2 3-3
Page C000h~FFFFh Cartridge
Slot A
Slot B
Page 8000h~BFFFh
Page 4000h~7FFFh Main-ROM Disk ROM
Page 0000h~3FFFh Sub-ROM


Note: No printer port!

External links