v1.4
PRECISION ARRAYS / THE AMICUBE V1.4 PROJECT
Spartan-7 logic.
Cortex-M7 control.
A new Spartan-7 FPGA and SAMV71 controller, connected by quad SPI. Two independent SDRAM channels and the physical 68000 interface keep classic computing at the heart of this 170 mm motherboard.
02 / HARDWARE EXPLORER
Explore the current native KiCad board, turn it over, or separate the connector and component groups to reveal the PCB beneath.
Interactive 3D is unavailable. Explore the native renders and assembly drawings below.
View assembly guide ↓The board Current native components, connectors and silkscreen.
Exploded view Separate component groups to see the board beneath.
Both faces Inspect the underside, pads and printed markings.
03 / THE ARCHITECTURE
Follow the design from programmable logic and memory to picture, sound and the connections around the board.
The Spartan-7 FPGA connects to two independent SDRAM channels, a translated 68000 socket and the SAMV71 Cortex-M7 controller through separate SPI, QSPI and configuration paths.
FOLLOW THE DESIGN
The XC7S100 brings 28 nm Spartan-7 logic and Vivado tooling to AmiCube, with two independent SDRAM channels and the physical MC68000 socket.
Two independent 64 MiB SDRAM channels and the physical 68000 interface retain their distinct roles.
The Spartan-7 implements the system logic. The SAMV71 provides a larger firmware and buffering foundation for storage, configuration and I/O.
BENEATH THE COMPONENTS
Signal routing, power and ground share a defined eight-layer stack. In1.Cu and In4.Cu provide the main internal ground references, with dedicated routing and supply layers between them.
04 / THE BOARD DESIGN
A physical CPU interface and programmable logic share one motherboard. Follow the design from the 68000 bus to the connections that make it a complete system.
V1.4 / NATIVE BOARDPHYSICAL 68000 · PROGRAMMABLE LOGIC
A 64-pin MC68000 socket connects to the Spartan-7 through dedicated level translation. All 60 signal pins have their own FPGA connection, bringing the physical processor into the programmable design.
170 MM / EIGHT LAYERSMINI-ITX FOOTPRINT · CLASSIC CONNECTIONS
Dual floppy headers, PS/2, DB9 controllers and serial sit alongside HDMI, USB and Ethernet. An ATX supply connection and front-panel header bring the board into a complete system.
The SAMV71 Cortex-M7 is rated for up to 300 MHz and provides 1 MiB flash and 384 KiB SRAM: four times the flash and six times the SRAM of the previous SAM7S256. SWD and a dedicated debug UART support bring-up.
QSPI adds four data lines, clock and chip select for runtime MCU–FPGA exchange. During the quad data phase it can carry four bits per SCK clock versus one for single-bit SPI: up to four times the raw payload per clock. Command, dummy and turnaround cycles affect actual throughput; FPGA configuration keeps its separate link.
Explore every connection ↗Current v1.4 development hardware. The model follows the saved PCB, including updated connector geometry. Device ratings describe capability: the new MCU/FPGA application, QSPI protocol and implemented timing still need integration and prototype testing. AmiCube’s hardware reset and CPU-release interlock are retained.
05 / THE ASSEMBLY BOOK
Start with top assembly, then turn the board over and explore its stackup, routing and power guides.
Open the 5-page board guide ↗06 / WHERE WE ARE
The latest routed board refines reset control, HDMI sideband protection, USB hub decoupling and floppy READY handling, with more clearance around nearby through-hole pads. Spartan-7 logic, SAMV71 control and the complete 68000 bus remain at its heart.
Source revision 5fd8fba · native geometry throughout.Top and bottom assembly, the eight-layer stackup, routing, power and buses. Regenerated from the same saved hardware snapshot as the interactive model.
Engineering checks document the design snapshot.Spartan-7 core porting, the SAMV71 application, QSPI protocol, storage and USB drivers, implemented timing and prototype qualification. The bring-up target is a foundation for this work.
Hardware and firmware validation continue together.