Carte Blanche FPGA CPU Socket Plug-On Board
A Field Programmable Gate Array-based Apple II processor socket plug-on board
Carte Blanche Atto installed in an Apple IIe replacing the 6502 processor with speaker cable connected direct to Atto.
Altium Project Archive
FPGA Configuration Bitstream
Altium Schematic and PCB Archive
Carte Blanche Atto has been updated to Virtualette.
Info on Virtualette can be found here.

Carte Blanche Atto is currently in the experimental stages of design. CB Atto is an FPGA processor socket (up to 40 pins) plug on PCB board designed to replace the main processor and provide additional or enhanced features for Apple II's, IIe's, IIc's and III's. The design is based around an exchangable FPGA module that allows the mixing and matching of FPGA speed, size and cost, depending on what processor it is replacing , or what additional peripherals it will be adding to its host address space.

Carte Blanche Atto brings new capabilities to its host machine. On the main Atto board, the following capabilities as well as physical IO are available;

- Replacement of existing CPU with a high speed synthesised FPGA CPU
- 4x uSD cards for extra hard disk volumes in addition to existing drives
- 12 Bit SVGA/VGA Interface (4096 colours unrestricted)
- Delta Sigma stereo audio, for such peripherals like a Mocking board
- A Single SD slot for wireless Ethernet
(11mbps with standard SPI interface or 54mbps with SDIO)
- 1MB fast SRAM
- 4MB Flash (Also used to store the FPGA's bit stream)
- A FPGA slot for selectable FPGA technology.
(The current version has a 1600E 1.6M gate FPGA)

The Atto, although having the same 40 pin DIP footprint as say an ASIC, is optimised to replace 6502 family devices only, as the board has been routed with clocking preferences given to those pins of the 6502 series that require clocking functions. With clocking aside, the 40 pin interface can be configured to suit any DIP40 (or less) device with the option to set either INPUT, OUTPUT, IO, GND, or VCC on each pin of the 40 pin interface. The Atto is powered via the host CPU socket.

The red and black cable you see in the photographs is the JTAG interface which also contains an out of band console, such as a UART or soft JTAG interface.

Carte Blanche Atto top view. The Wireless Ethernet SD card is underneath the FPGA module.
Carte Blanche Atto with the FPGA module open, revealing the SD wireless Ethernet card.
Underside of Carte Blanche Atto showing the 40 pin processor interface, the four Micro SD card sockets, VGA and Audio interfaces.
The Atto in an Apple IIc. Notice the speaker cable connects direct to the Atto's speaker connector.
The Atto in an Apple IIc. The edge of the Wireless Ethernet card can be seen under the FPGA module.
Just not right. A 700MHz ARM7 front side bus interfaced to the Apple IIe's bus. The pictured green plug on board is a Gumstix OMAP module running Linux 2.6