keyboard with the TRS- 80. This device also supports
keyboard macros and correctly resets the Color Computer
when the Ctrl-Alt-Delete sequence is keyed in.
Another innovative product that Cloud- 9 has is the
SuperSD. This device — a complete embedded system
with the ATMEL AVR Xmega 128a1 as its heart — allows
using an SD memory card with the TRS- 80.
The SD card behaves as though it were a solid-state
hard drive, and can be used to store files or ROM images.
SuperSD can load these images into the CoCo’s memory
space emulating a 32K ROM, provided that Tandy’s
specifications are followed. This will make it easy to load
OSes whose image is stored in the SD card in a
SuperSD is compatible with the FAT file system, using
the onboard 64K of fast static RAM to hold the FAT file
handle buffers. This means that files can easily be read
and written by a DOS/Windows computer, and read or
written by the SuperSD. In addition to holding file
allocation table information, the memory is also used for
the Ethernet buffers and extended memory for the AVR
SuperSD will use the Drive Wire protocol to
communicate between it and the TRS- 80. In addition, this
device will also provide a Wiznet expansion slot. Wiznet
will be supported by using SPI (Serial Peripheral Interface)
controlled by the AVR. Using this platform, Ethernet
connectivity will be possible. Lots of firmware that
supports various protocols is ready for action, with more
on the way.
Another useful feature will be the implementation of
AES 128-bit encryption for the firmware files. This allows
Cloud- 9 to post updates to the firmware on their website.
The SuperSD owner only needs to download these files
and store them in the SD per instructions. SuperSD will
decrypt these files and update its firmware.
HAWKSoft — owned and operated by Christopher
Hawks — had a display at the CoCoFEST! HAWKSoft is a
vendor that provides hardware and software for the Color
Computer. Some noted products include an RGB to S-video converter and software that allows NitrOS- 9 to read
By far the most interesting item at the HAWKSoft
booth was the Raspberry Pi (RPi) Color Computer. At first
glance, it looked just like any other Color Computer 3
with its full travel keyboard and white case, but as Chris
explained it was anything but just another Color
First of all, there was no CoCo 3 motherboard or
electronics inside the case. Instead, there was a Raspberry
Pi that booted into Linux. A CoCo emulator ran within the
Linux environment to provide the familiar green welcome
Next, Chris built a small circuit based on the Atmel
tinyAVR microcontroller to interface the Raspberry Pi to
the TRS- 80’s keyboard. The small circuit sensed whatever
key was pressed on the keyboard and sent the relevant
information via the USB interface to the Raspberry Pi.
Chris also added a USB hub and installed it inside the
Color Computer case. The various USB ports could be
seen peering out of the computer’s cartridge slot.
The emulator software took care of correctly
interpreting the pressed keys and taking the corresponding
action. Chris used the MESS CoCo emulator which works
under Linux. MESS is Multiple Emulator Super System, and
is capable of emulating various computer systems.
Chris mentioned that the version running on the
RPi was a stripped down adaptation that only
emulated the Color Computer. This helped reduce
the size of the application to something more
At the time of this writing, Chris was working on
putting the software in a publicly available DropBox
resource, along with an article that will describe how
anyone can build their own RPi Coco. The article will
be published in the Glenside Color Computer Club
newsletter. The club makes the newsletter available to
everyone free of charge. Go to www.glensideccc.com
to find out how you can receive it.
56 March 2015
HAWKSoft’s Raspberry Pi CoCo 3.
Richard Crislip’s exhibit showcasing Drive Wire.