

Ps2usb
Adapting USB devices to work on old computers
- Size
- 40 × 55 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 26
- Nets
- 50
- Pads
- 174
- Tracks, vias
- 413, 49
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 14 Aug 2022
- Updated
- 13 Sep 2026
Overview
Ps2usb is an open-source printed circuit board by rasteri, from the rasteri/HIDman repository on GitHub. It is a 2-layer board of 40 × 55 mm with 26 parts on 50 nets, routed with 413 tracks and 49 vias.
It is built around the MAX232N and B3173BGR-20C0001Q3U1930. Its parts include 12 capacitors, 5 connectors, 2 ICs, 1 diode and 1 switch. It belongs with the keyboards and input boards and the 8051 (CH55x, STC, AT89) boards of this library.
Main components
2README
README.mdHIDman
USB HID to XT / AT / PS/2 / Serial converter
HIDman is an open source device to allow the use of modern USB keyboards and mice on legacy PCs.
Peripherals that support legacy PCs are becoming hard to find, especially for the very first PCs. This project aims to provide a simple cheap solution that will cover everything from the original IBM 5150 PC all the way up to modern computers that have PS/2 ports.
<img src=/images/hidmanfront.jpg width=50%/> <img src=/images/hidmanrear.jpg width=50%/>
Features
- (should) Support the majority of standard USB keyboards and mice, including ones that use wireless dongles.
- Also supports (some) USB Game controllers - buttons/axes are mapped to keypresses or mouse actions
- Can emulate the following keyboards :
- Original IBM PC, XT and clones
- AT / PS/2
- Amstrad PC (PC1512, PC1640, PC2xxx, PC3xxx, PC4xxx)
- And the following mice :
- Serial Mouse (with optional Logitech-style 3rd button)
- PS/2 Mouse (with optional Intellipoint-style scroll wheel and up to 5 buttons)
- Driverless configuration menu - change settings just by opening a text editor
How to get one
Purchase :
- I have some for sale on my tindie page - https://www.tindie.com/products/rasteri/hidman/
- If you're in the US, retro hack shack also has stock - https://retrohackshack.com/product/hidman-usb-keyboard-converter/
DIY :
- Grab an assembled PCB from PCBway : https://www.pcbway.com/project/shareproject/HIDman_USB_to_Retro_PC_Adapter_3b4fb5d5.html
- Also grab the front plate : https://www.pcbway.com/project/shareproject/Front_enclosure_plate_for_HIDman_0aec2ae9.html
- And the rear plate : https://www.pcbway.com/project/shareproject/Rear_Enclosure_for_HIDman_c0ff0b8a.html
- And the enclosure : https://lincolnbinns.com/e-case-a-black-40mm.html
- Don't forget 8x screws : https://lincolnbinns.com/e-case-screws.html (I suggest the thread former ones)
- After assembling the unit, you will need to install firmware. See the "Firmware Update" section below.
Quickstart Guide
USB Connection
You can connect many different combinations of USB devices to HIDman.
The most obvious being to connect a keyboard to one USB port, and a mouse to the other one :
<img src=/images/usbsetup1.svg width=300/>
Or, you could perhaps connect a wireless keyboard+mouse dongle to one port, and a game controller to the other :
<img src=/images/usbsetup2.svg width=500/>
Hub support can be hit-and-miss. This is (mostly) not HIDman's fault - many modern hubs don't support low-speed USB devices properly.
Newer PCs (PS/2)
- Connect male-to-male Mini-DIN cables from HIDman’s keyboard and mouse ports to your PC’s PS/2 ports.
- Turn on your PC.
- If necessary, press HIDman's ⏻ power button to select PS/2 mode (light blue).
<img src=/images/newerpcs.svg width=400/>
Older PCs (AT/XT and Serial)
- Connect a male-to-male Mini-DIN Cable from HIDman's keyboard port into a Mini-DIN to DIN adapter.
- Connect that adapter to your PC's keyboard port.
- Connect a straight-through male-to-female DE-9 cable from HIDman's serial port to your PC's serial port.
- Turn on your PC.
- Press HIDman's ⏻ power button to select AT mode (light blue), or XT mode (orange) for early 80's IBM PCs and clones.
<img src=/images/olderpcs.svg width=500/>
Configuration
Configuration is provided through a built-in menu system. No software install is required - all interaction is through the keyboard.
Simply open a text editor on your target PC (eg notepad, edit, vi), then hold HIDman's power button for a few seconds. The menu will be typed out into your text editor.
<img src=/images/menu1.png width=394/>
"Adv.Keyboard" and "Adv.Mouse" switch the keyboard and mouse respectively into "Native Mode". This may be required to access certain functions such as scroll wheels and extra buttons on mice.
Note : Some USB devices with both keyboard and mouse interfaces (e.g. mice with configurable buttons) require both Adv.Keyboard and Adv.Mouse to be enabled otherwise they behave unpredictably.
"Intellimouse" enables scroll wheel and 5-button support for PS/2 mice.
"Debug" enables the debug menu. The most useful debugging option is "Dump HID Data". Enabling this dumps information about all USB devices connected after that point.
<img src=/images/menu2.png width=450/>
If you are having trouble getting a USB device to work, enable HID Dumping then connect the troublesome USB device. Wait for it to finish dumping, then press ESC and save the resulting data to a text file. Then send it to me for analysis.
Firmware Update
Firmware development is continuing, so if you have problems it's always worth updating to the latest version.
If you're on windows, first install WCH's ISP tool - https://www.wch.cn/downloads/WCHISPTool_Setup_exe.html If on Mac or Linux, install ch55xtool : https://github.com/MarsTechHAN/ch552tool
The next step is to put the HIDman in firmware update mode.
- Disconnect everything from HIDman, including all USB devices and PCs. (failure to do this may result in damage to HIDman, your PC, or both).
- Hold down HIDman's ⏻ power button.
- Use a USB A-to-A cable to connect HIDman's LOWER USB port to a USB port on your modern PC.
If HIDman doesn't appear in your computers' device list, follow the instructions in the "Debricking" section below.
After that, update instructions will depend on your operating system.
Windows
Follow the instructions in this diagram :
<img src=/images/firmware2.svg width=800/>
Linux or Mac
Pass the -f parameter to ch55xtool specify the firmware file to load. For example :
python3 ch55xtool.py -f hidman_axp_v1.1.binDebricking
If this is your first time programming HIDman, or you accidentally program a corrupted firmware, you can force it into firmware update mode another way. It can be a bit fiddly though.
<img src=/images/C5.png width=500/>
- Disassemble HIDman.
- Connect the two pads of component C5 (shown above) together using a pair of tweezers or similar.
- While keeping the pads connected, use a USB A-to-A cable to connect HIDman's LOWER USB port to a USB port on your modern PC.
Advanced Setups
Combined PS/2 port
HIDman actually outputs keyboard and mouse signals on BOTH PS/2 connectors. If you have a PC that can take advantage of this (typically Mini PCs or Laptops), you can keep the cabling neater by using only one cable. NOTE : You will need to enable "PS2 AUX Output" in the advanced menu.
<img src=/images/combined1.svg width=500/>
Note that there are two different types of Combined PS/2 ports, and HIDman provides for both types. Generally, laptops will need plugged into the Mouse port on HIDman, and Mini PCs want the Keyboard port. If it doesn't work with one port, try the other one.
Splitter
Another way to take advantage of the Combined PS/2 port functionality is to use a widely-available PS/2 splitter :
<img src=/images/splitter.svg width=500/>
This also allows neater cabling, as you could connect both keyboard and mouse ports to the rear, and not have to connect to the front mouse port.
Technical description
The HIDman is based around the CH559 from WCH, a remarkably flexible chip with two USB HOST ports. This makes it ideal for our purposes.
The code is forked from atc1441's excellent repository - https://github.com/atc1441/CH559sdccUSBHost
PCB and enclosure was designed in KiCad - source files are in the hardware directory.
Development is very active but it is usable in its current state.
Parts
26| Qty | Value | Footprint | References |
|---|---|---|---|
| 10 | 3.3u | Capacitor_SMD:C_0603_1608Metric | C1, C2, C3, C4, C6, C7, C8, C9, C10, C12 |
| 2 | 10pF | Capacitor_SMD:C_0603_1608Metric | C5, C11 |
| 2 | 1K | Resistor_SMD:R_Array_Convex_4x0603 | RN1, RN2 |
| 2 | DIN8 | ps2usb:DIN8 | J1, J3 |
| 1 | 12MHz | Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm | Y1 |
| 1 | 150 | Resistor_SMD:R_Array_Convex_4x0603 | RN3 |
| 1 | 500mA | Fuse:Fuse_1206_3216Metric | F1 |
| 1 | B3173BGR-20C0001Q3U1930 | ps2usb:B3173BGR-20C0001Q3U1930 | D1 |
| 1 | CH559L-less | ps2usb:QFP-12x12_14x14_Pitch0.5mm | U1 |
| 1 | Conn_01x03_Pin | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J5 |
| 1 | DE9 | Connector_Dsub:DSUB-9_Female_Horizontal_P2.77x2.84mm_EdgePinOffset7.70mm_Housed_MountingHolesOffset9.12mm | J4 |
| 1 | MAX232 | Package_SO:SOIC-16_3.9x9.9mm_P1.27mm | U2 |
| 1 | RATACSWITCH | ps2usb:TS11 | S1 |
| 1 | USB1035 | ps2usb:USB1035 | J2 |
Questions
How big is the Ps2usb PCB?
It measures 40 × 55 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Ps2usb use?
26 parts, built around the MAX232N and B3173BGR-20C0001Q3U1930. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Ps2usb KiCad files?
From the rasteri/HIDman repository on GitHub, at the commit this page was made from: the board is hardware/axp/ps2usb.kicad_pcb and its schematic hardware/axp/enclosure/frontcase/frontcase.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Ps2usb design in my own project?
Its repository states no licence, so its author keeps all rights: ask rasteri before reusing the design.
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