Bring your RCBus/RC2014 build into the 90's with true native support for Universal Serial Bus. Enable the Z80 drivers in a new RomWBW ROM images and then connect your system to:
- USB Hubs
- USB flash devices
- USB magnetic mechanical hard disks
- USB 3.5" Floppy drives
- USB Keyboards
- And Many more types to come..
There are plans to update the software to further improve keyboard support, and add support for other USB devices, such as USB to Centronics adapters for dot matrix printers, ethernet adapters, and other useful USB devices.
General Description
This is a kit based on the CH376 USB Module.
The CH376 module provides a high level interface for connecting to the most common mass storage devices, but that interface is limited and will not work through hubs. The CH376 module also supports driving the USB communication directly, enabling the ability to operate any compatible USB device. The drivers I originally wrote for MSX-DOS have been ported to RomWBW. These drivers, written in C for the Z80, fully support enumerating and discovering the attached USB devices, and enable the Z80 to understand the 'USB Protocol' directly.
Key features
- USB 1.1/2.0 compatible (although certainly not certified)
- Tested with a large assortment of flash drives, HDD, Floppy, and hubs.
- Drivers written in C so a little more accessible than pure Z80 assembly
- Individually programmable LEDs to indicate USB operation
Testing Status
The correct interfacing with any USB device is mostly limited by the software drivers that have been specifically written to enable appropriate support under MSX-DOS/NEXTOR. So any limitation or issue can probably, once identified, be corrected with a software update.
There has certainly not been any USB certification conducted. Just lots of manual testing by me. There are possibly still things in the software that are not following the rules.
Hot swapping of devices is not supported. Insert your USB devices then power on or reset. You can change floppies, but unpluging and re-inserting any USB device will require a reboot
Please note, that due to some timing limitation of the CH376 mode, some devices or the module itself, may fail to get detected on initial boot/power-on. Hit the reset button and it should be detected fine.
There are 4 main USB classes implemented to date:
- enumeration/discovery of devices through USB hubs.
- UFI which is used by floppy drives
- SCSI which is used by flash, HDD and other large storage devices
- HID for a keyboard (requires an appropriate video module to be installed and enabled)
What's included in this kit
The full kits includes everything you need (PCB, capacitors, IC sockets, CH376S module, connectors, and the ICs). And an optional small Flash drive that's been tested and confirmed to work.
Bill of Materials
| Count | Name |
|---|---|
| 4 | 0.1uF |
| 1 | 220uF |
| 3 | 1N4148 |
| 2 | 3mm leds |
| 1 | 4.7kΩ (3mm) |
| 2 | 470Ω Resistor (3mm) |
| 1 | CH376S USB Module |
| 1 | 74HCT138 |
| 1 | 74HCT32 |
| 1 | 74HC74 |
| 2 | Right Angle 1x20 Header |
| 2 | 14 POS IC SOCKET |
| 1 | 16 POS IC SOCKET |
| 1 | 512MB USB Flash Drive (optional) |
What else do I need to make this work?
- A working RC2014/RCBus system
- An updated RomWBW ROM image configured to enable the CH376 'native' driver.
More information
More information can be found on my website:
https://www.dinoboards.com.au/usb-for-rc
Disclaimer
Please note that this is a kit, produced by a non-expert (me) for hackers, DIYers' and retro lovers, to tinker with. Please exercise caution and follow good safety practices. You will be working with sharp knives, a hot soldering iron, and small metal components. Be mindful of the risks involved in the build process. I will do my best to answer any questions you may have.
This kit is provided as-is, with no guarantees or warranties. By assembling and using this kit, you acknowledge that you do so at your own risk. The creator cannot be held responsible for any damage, injury, or loss that may occur during the assembly or operation of this kit.
Links to code and documentation
Documentation (dinoboards.com.au)
Design Files (dinoboards.com.au)
Shipping policy
Normally shipped next working day, however during busy periods this may extend slightly.
It is your responsibility to pay any import duty or other taxes where appropriate.
For EU locations:
* Please see Lectronz's Terms and Condititions (https://lectronz.com/pages/terms_and_conditions)
* For order 150 EUR or over, it will be your responsibility to pay any import duty or other taxes where appropriate.
