Category:Sony HB-10
This page was last modified 09:08, 20 February 2022 by Gdx. Based on work by Mars2000you and Rderooy and others.



For its 3rd series of MSX1 computers, Sony has choosen the simplicity. The design remains similar to the HB-101 and HB-201 series, but all the extras such as firmware and pause or reset button have been removed. The following models exist:

Product Region Keyboard Video and audio out Colour
Sony HB-10 JP QWERTY/JP50on RF, Composite video and audio Red, Black or Gray
Sony HB-10B UK QWERTY with £ key RF, Composite V+A DIN Black
Sony HB-10D DE QWERTZ RF, Composite V+A DIN Black
Sony HB-10P NL QWERTY with £ key RF, Composite V+A DIN Black
ES QWERTY with ñ key

The power supply, a model out of the Sony AC-HB1 series, depending on target region, is external and its connector is proprietary.

Brand Sony
Model HB-10 / HB-10B / HB-10D / HB-10P
Year Late 1985 (HB-10) or 1986 (other models)
Region HB-10: Japan
HB-10B: United Kingdom
HB-10D: Germany
HB-10P: Netherlands and Spain
Launch price JP: ¥34,800
UK: £89.00
RAM 16kB in slot 0 (HB-10) or 64kB in slot 3 (other models)
Media Cartridges
Video Texas Instruments TMS9118NL (HB-10) or Toshiba T6950 (other models)
Audio PSG (YM2149F integrated in MSX-Engine S3527)
Chipset Yamaha S3527
Keyboard layout see table above
Emulation ROM dumped and emulated for the HB-10 and HB-10P versions. ROM dumps needed for all other versions. See this thread for details


Check also the pages about the different models!

Sony HB-10 (black)
Sony HB-10 (red)
Sony HB-10 (pale gray)
Sony HB-10D
Sony HB-10P with 'International' keyboard
Sony HB-10P with Spanish keyboard
Sony HB-10 Power supply (red)
Sony HB-10D PCB
Sony HB-10P PCB
Sony HB-10 back
Sony HB-10P back
Sony HB-10 all models right side


The HB-10 is a MSX1 with a Z80A from NEC (DA780C-1) or Sharp (LH0080A) and an MSX-Engine from Yamaha (S3527).

The used VDP outside Japan is the Toshiba T6950, which does not support some undocumented features of the Texas Instruments TMS9918, TMS9928 and TMS9929 VDP's.

The 16kB model can be upgraded to 64kB by replacing the two 4416 chip with 4464 and add the components: C43 (390pF), C53 (100pF), R62 (47kΩ) and Q4 (NPN transistor like 2SC1815). Then you also need to move the resistor R61(N) to R61(P).

The PSG volume balance with sound expansion cartridges can be improved by replacing R22 (10kΩ) by an 1kΩ and R15 (10k) by a 4.7kΩ. (HB-10B, HB-10D and HB-10P)

Slot Map for 16kB model

Slot 0 Slot 1 Slot 2 Slot 3
Page C000h~FFFFh 16kB RAM Cartridge
Slot 1
Slot 2
Page 8000h~BFFFh
Page 4000h~7FFFh Main-ROM
Page 0000h~3FFFh

Slot Map for 64kB models

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

(*) RAM mirror quirk


Fixes, Repair and Upgrades

Quirk on port A8h (RAM mirror)

All the HB-10 models with 64kB RAM and some very early versions of the HB-20P have a quirk on port A8h that makes RAM Page 3 appear both in slot 0 and in slot 3. This mirroring effect is emulated in openMSX for the Sony HB-10P, it can be very annoying as it can play havoc with games that need more than 16kB RAM, using the 16kB RAM mirror to store system variables and assuming that all the ram is in the same slot 0 as page 3.

This configuration can cause poorly written software to crash. Nevertheless, you can run these games if you type following command before loading:

OUT &hA8,240

For cartridges, the trick is to plug it after booting using a slot expander that has switches to disable each slot and prevent them from auto booting (WARNING!! Do not insert a cartridge when power is ON. It can damage the machine). Then type the following instructions on BASIC after re-enabling the slot:

OUT&hA8,240: DEFUSR=&H7D75: ?USR(0)

Alternatively, you can use ROM loaders like Execrom, LoadROM or OPFX /X. Since they start the game from MSX-DOS, this problem will be automatically solved as DOS already selects the proper slots for the RAM.

This quirk RAM mirror can be removed with the following minor modification. (HB-10B, HB-10D and HB-10P)

Sony HB-10 mirror fix (diagram)
Sony HB-10 mirror fix (PCB)

Links to fixes, repair and upgrades


Pages in category "Sony HB-10"

The following 4 pages are in this category, out of 4 total.