Description

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 devicesHID 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.

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.