Sanyo PHC-77
This page was last modified 10:33, 14 April 2019 by Rderooy. Based on work by Mars2000you and Gdx 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.

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.

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
Type PHC-77
Year 1987
Region Japan
Original 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
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 on floppy disk


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 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 is in 3 parts: access to the Word Processor, Settings, access to MSX-BASIC. In the Settings, you can choose to work in MSX(1) mode -15 characters- or MSX2 mode -30 characters- and 3 different layouts are available. MSX-Write does not have a SRAM. Savings need to be done on disk, tape or (temporary) memory disk.



Sanyo PHC-77
Sanyo PHC-77 back
Sanyo PHC-77 right side
Sanyo PHC-77 folded
Sanyo PHC-77 unit, manuals and floppy disk
Sanyo PHC-77 dark brown
Sanyo PHC-77 mainboard
Sanyo PHC-77 printer board
Sanyo PHC-77 label
MSX-Write PCB underside


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


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. FDC controller is the MB8877 from Fujitsu.

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

Slot Map

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


External links