Original processor, programmable chipset
The MC68000 connects to the Spartan-3 XC3S400 through level translators. Six SRAM devices provide 6 MiB of memory. The AT91SAM7S256 handles storage and control.
MINIMIG.CA / HARDWARE DOCUMENTATION
Minimig 1.98 ITX
The original Amiga architecture, in a 170 × 170 mm Mini-ITX board: a physical MC68000, Spartan-3 FPGA and 6 MiB SRAM, with an ARM controller for storage and the on-screen menu.
October 17, 2026 engineering snapshot · 33 A4 schematic sheets · 380 schematic components
Related circuits are consolidated into 33 sheets. Labels and drawings have clear margins; the five-page A4 board guide uses tightly cropped transparent board views and 1:2 assembly plans.
A familiar machine. A clearer design.
Organized by function
Power, FPGA, control, interfaces and mechanical sheets form the hierarchy. All original pin numbers, signal connections, component values and PCB geometry are preserved.
Classic connections
PS/2 keyboard and mouse, DB9 controllers, RGB video and serial meet microSD storage, Mini-USB service, ATX power and front-panel controls.
The board, from every angle.
Five engineering drawings cover assembly, the six-layer stack, routing, power and buses.
Top assembly
Vector drawing ↗
Bottom assembly
Vector drawing ↗
Stackup and fabrication
Vector drawing ↗
Routing guide
Vector drawing ↗
Power and signals
Vector drawing ↗
Connections, pin by pin.
Search or expand a connector to trace its signals. Pin tables describe the circuit; use the assembly drawing to confirm the physical orientation.
J1 · DB15_Female 16 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 3 | BLUE-OUT | 3_3 | passive |
| 0 | Frame0 | Frame_0 | passive |
| 10 | GND | P10_10 | passive |
| 5 | GND | 5_5 | passive |
| 6 | GND | 6_6 | passive |
| 7 | GND | 7_7 | passive |
| 8 | GND | 8_8 | passive |
| 2 | GREEN-OUT | 2_2 | passive |
| 13 | HSYNC-OUT | P13_13 | passive |
| 1 | RED-OUT | 1_1 | passive |
| 14 | VSYNC-OUT | P14_14 | passive |
| 9 | unconnected-(J1-P9-Pad9) | P9_9 | passive+no_connect |
| 12 | unconnected-(J1-P12-Pad12) | P12_12 | passive+no_connect |
| 15 | unconnected-(J1-P15-Pad15) | P15_15 | passive+no_connect |
| 11 | unconnected-(J1-P111-Pad11) | P111_11 | passive+no_connect |
| 4 | unconnected-(J1-Pad4) | 4_4 | passive+no_connect |
J10 · Spare I/O 10 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 10 | GND | Pin_10_10 | passive |
| 2 | GND | Pin_2_2 | passive |
| 4 | GND | Pin_4_4 | passive |
| 6 | GND | Pin_6_6 | passive |
| 8 | GND | Pin_8_8 | passive |
| 1 | VCC +5VREG | Pin_1_1 | passive |
| 3 | VCC +5VREG | Pin_3_3 | passive |
| 5 | VCC +5VREG | Pin_5_5 | passive |
| 7 | VCC +5VREG | Pin_7_7 | passive |
| 9 | VCC +5VREG | Pin_9_9 | passive |
J11 · JTAG 6 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 5 | GND | Pin_5_5 | passive |
| 4 | TCK | Pin_4_4 | passive |
| 2 | TDI | Pin_2_2 | passive |
| 3 | TDO | Pin_3_3 | passive |
| 1 | TMS | Pin_1_1 | passive |
| 6 | VCC +3.3V | Pin_6_6 | passive |
J12 · Micro_SD_Card 13 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| P7 | /Control/mcu usb sd/DAT0 | DAT0_P7 | bidirectional |
| S1 | Frame0 | Frame_S1 | passive |
| S2 | Frame0 | Frame_S2 | passive |
| S3 | Frame0 | Frame_S3 | passive |
| S4 | Frame0 | Frame_S4 | passive |
| P6 | GND | VSS_P6 | power_in |
| P4 | Net-(J12-VDD) | VDD_P4 | power_in |
| P5 | SDCARD_CLK | CLK_P5 | input |
| P3 | SPI_DIN | CMD_P3 | input |
| C1 | unconnected-(J12-CD-PadC1) | CD_C1 | input+no_connect |
| P8 | unconnected-(J12-DAT1-PadP8) | DAT1_P8 | bidirectional+no_connect |
| P1 | unconnected-(J12-DAT2-PadP1) | DAT2_P1 | bidirectional+no_connect |
| P2 | ~{MMC_SEL_ARM} | DAT3/CD_P2 | bidirectional |
J13 · Amiga-SERIAL 2 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 2 | +3V3_Amiga_Serial_Minimig | Pin_2_2 | passive |
| 1 | VCC +3.3V | Pin_1_1 | passive |
J14 · ON-OFF 2 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 2 | GND | Pin_2_2 | passive |
| 1 | PS_ON | Pin_1_1 | passive |
J15 · ARM-SERIAL 2 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 2 | +3V3_Arm_Serial_Minimig | Pin_2_2 | passive |
| 1 | VCC +3.3V | Pin_1_1 | passive |
J16 · ESP-01 8 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 4 | +3V3_WIFI_Minimig | Pin_4_4 | passive |
| 8 | +3V3_WIFI_Minimig | Pin_8_8 | passive |
| 1 | GND | Pin_1_1 | passive |
| 2 | WIFI_RXD | Pin_2_2 | passive |
| 7 | WIFI_TXD | Pin_7_7 | passive |
| 3 | unconnected-(J16-Pin_3-Pad3) | Pin_3_3 | passive+no_connect |
| 5 | unconnected-(J16-Pin_5-Pad5) | Pin_5_5 | passive+no_connect |
| 6 | ~{MCLR} | Pin_6_6 | passive |
J17 · DE9_Plug_MountingHoles 10 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 8 | D_CTS | 8_8 | passive |
| 7 | D_RTS | 7_7 | passive |
| 2 | D_RXD | 2_2 | passive |
| 3 | D_TXD | 3_3 | passive |
| 0 | Frame0 | PAD_0 | passive |
| 5 | GND | 5_5 | passive |
| 4 | Net-(J17-Pad4) | 4_4 | passive |
| 6 | Net-(J17-Pad4) | 6_6 | passive |
| 1 | unconnected-(J17-Pad1) | 1_1 | passive+no_connect |
| 9 | unconnected-(J17-Pad9) | 9_9 | passive+no_connect |
J2 · 874272442 24 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 9 | 5VSB | 9_9 | passive |
| 10 | 12V-Supply | 10_10 | passive |
| 11 | 12V-Supply | 11_11 | passive |
| 15 | GND | 15_15 | passive |
| 17 | GND | 17_17 | passive |
| 18 | GND | 18_18 | passive |
| 19 | GND | 19_19 | passive |
| 24 | GND | 24_24 | passive |
| 3 | GND | 3_3 | passive |
| 5 | GND | 5_5 | passive |
| 7 | GND | 7_7 | passive |
| 16 | PS_ON | 16_16 | passive |
| 8 | PWROK | 8_8 | passive |
| 1 | unconnected-(J2-Pad1) | 1_1 | passive+no_connect |
| 2 | unconnected-(J2-Pad2) | 2_2 | passive+no_connect |
| 4 | unconnected-(J2-Pad4) | 4_4 | passive+no_connect |
| 6 | unconnected-(J2-Pad6) | 6_6 | passive+no_connect |
| 12 | unconnected-(J2-Pad12) | 12_12 | passive+no_connect |
| 13 | unconnected-(J2-Pad13) | 13_13 | passive+no_connect |
| 14 | unconnected-(J2-Pad14) | 14_14 | passive+no_connect |
| 20 | unconnected-(J2-Pad20) | 20_20 | passive+no_connect |
| 21 | unconnected-(J2-Pad21) | 21_21 | passive+no_connect |
| 22 | unconnected-(J2-Pad22) | 22_22 | passive+no_connect |
| 23 | unconnected-(J2-Pad23) | 23_23 | passive+no_connect |
J3 · KMDGX-6S_6S-S4N1 17 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| A6 | /Interfaces/ps2/KBDCLK-CON | A6_A6 | passive |
| A8 | /Interfaces/ps2/KBDCLK-CON | A8_A8 | passive |
| MH1 | Frame0 | MH1_MH1 | passive |
| MH2 | Frame0 | MH2_MH2 | passive |
| MH3 | Frame0 | MH3_MH3 | passive |
| MH4 | Frame0 | MH4_MH4 | passive |
| MH5 | Frame0 | MH5_MH5 | passive |
| A3 | GND | A3_A3 | passive |
| B3 | GND | B3_B3 | passive |
| A1 | KBDDAT-CON | A1_A1 | passive |
| A2 | KBDDAT-CON | A2_A2 | passive |
| B6 | MSCLK-CON | B6_B6 | passive |
| B8 | MSCLK-CON | B8_B8 | passive |
| B1 | MSDDAT-CON | B1_B1 | passive |
| B2 | MSDDAT-CON | B2_B2 | passive |
| A5 | VCC +5VREG | A5_A5 | passive |
| B5 | VCC +5VREG | B5_B5 | passive |
J4 · Front panel 12 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 7 | DISKLED_H_+ | Pin_7_7 | passive |
| 8 | DISKLED_H_- | Pin_8_8 | passive |
| 12 | GND | Pin_12_12 | passive |
| 4 | GND | Pin_4_4 | passive |
| 6 | GND | Pin_6_6 | passive |
| 11 | Net-(J4-Pin_11) | Pin_11_11 | passive |
| 9 | PWRLED_H+ | Pin_9_9 | passive |
| 10 | PWRLED_H- | Pin_10_10 | passive |
| 1 | PWR_ATX | Pin_1_1 | passive |
| 2 | PWR_ATX_G | Pin_2_2 | passive |
| 5 | SW6_Push | Pin_5_5 | passive |
| 3 | ~{MCLR} | Pin_3_3 | passive |
J5 · 178-009-613R571 22 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| B2 | /Interfaces/joystick/JOYA4-CON | B2_B2 | passive |
| A7 | /Interfaces/joystick/JOYB0-CON | A7_A7 | passive |
| A5 | /Interfaces/joystick/JOYB1-CON | A5_A5 | passive |
| A3 | /Interfaces/joystick/JOYB2-CON | A3_A3 | passive |
| A2 | /Interfaces/joystick/JOYB4-CON | A2_A2 | passive |
| MH1 | Frame0 | MH1_MH1 | passive |
| MH2 | Frame0 | MH2_MH2 | passive |
| MH3 | Frame0 | MH3_MH3 | passive |
| MH4 | Frame0 | MH4_MH4 | passive |
| A6 | GND | A6_A6 | passive |
| B6 | GND | B6_B6 | passive |
| B7 | JOYA0-CON | B7_B7 | passive |
| B5 | JOYA1-CON | B5_B5 | passive |
| B3 | JOYA2-CON | B3_B3 | passive |
| B1 | JOYA3-CON | B1_B1 | passive |
| B8 | JOYA5-CON | B8_B8 | passive |
| A1 | JOYB3-CON | A1_A1 | passive |
| A8 | JOYB5-CON | A8_A8 | passive |
| A4 | VCC +5VREG | A4_A4 | passive |
| B4 | VCC +5VREG | B4_B4 | passive |
| A9 | unconnected-(J5-PadA9) | A9_A9 | passive+no_connect |
| B9 | unconnected-(J5-PadB9) | B9_B9 | passive+no_connect |
J6 · WiFi-ON 2 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 2 | +3V3_WIFI_Minimig | Pin_2_2 | passive |
| 1 | VCC +3.3V | Pin_1_1 | passive |
J7 · SJ1-3514 4 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 2 | AUDIOL-CON | passive | |
| 4 | AUDIOL-CON | passive | |
| 3 | AUDIOR-CON | passive | |
| 1 | GND | passive |
J8 · RAPC712X 3 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| PIN | 12V-Supply | passive | |
| SLEEVE | GND | passive | |
| SHUNT | unconnected-(J8-PadSHUNT) | passive+no_connect |
J9 · USB_B_Mini 6 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 3 | /Control/mcu usb sd/D-TO-CON+ | D+_3 | bidirectional |
| 2 | /Control/mcu usb sd/D-TO-CON- | D-_2 | bidirectional |
| 6 | Frame0 | Shield_6 | passive |
| 5 | GND | GND_5 | passive |
| 4 | unconnected-(J9-ID-Pad4) | ID_4 | passive+no_connect |
| 1 | unconnected-(J9-VBUS-Pad1) | VBUS_1 | power_out+no_connect |
SW2 · PAL/VGA 3 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 1 | 15KHz | A_1 | passive |
| 2 | GND | B_2 | passive |
| 3 | GND | C_3 | passive |
SW3 · Fast SPI 3 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 2 | MCC_CLKEN | B_2 | passive |
| 1 | SPI_CLK | A_1 | passive |
| 3 | unconnected-(SW3-C-Pad3) | C_3 | passive+no_connect |
SW4 · SW_Reset 4 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 3 | Frame0 | Frame0_3 | passive |
| 4 | Frame0 | Frame0_4 | passive |
| 2 | GND | 2_2 | passive |
| 1 | ~{MCLR} | 1_1 | passive |
SW5 · SW_Menu 4 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 3 | Frame0 | Frame0_3 | passive |
| 4 | Frame0 | Frame0_4 | passive |
| 2 | GND | 2_2 | passive |
| 1 | SW6_Push | 1_1 | passive |
SW6 · SW_ATX 4 pins
| Pin | Net | Signal | Type |
|---|---|---|---|
| 3 | Frame0 | Frame0_3 | passive |
| 4 | Frame0 | Frame0_4 | passive |
| 1 | PWR_ATX | 1_1 | passive |
| 2 | PWR_ATX_G | 2_2 | passive |
The schematic index.
| Sheet | Function | Components |
|---|---|---|
| 01 | System overview | |
| 02 | Power input, protection and rails | |
| 03 | ATX power and front panel | C110, C141, C142, D14, J2, J4, J14, R19, R20, R21, R22, R68, SW6, U7 |
| 04 | Power input and buck regulator | C23, C24, C25, C26, C27, C98, CR1, D1, D6, F1, FB4, J8, L1, R1, R10, R12, R13, R14, R136, TP4, TP5, TP6, TP7, TP8, TP9, TP10, U6 |
| 05 | Regulated rails — 3.3 V, 1.25 V and 2.5 V | C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C13, C16, C28, C29, D2, D3, D4, FB1, FB2, FB3, Q2, Q3, R2, R3, R4, R5, R6, R7, R8, R9, R99, R137, R138, TP1, TP2, TP3, U3, U4, U5 |
| 06 | Spartan-3, clocks and memory | |
| 07 | Spartan-3 — MC68000 interface | IC1 |
| 08 | Spartan-3 — Asynchronous SRAM interface | IC1 |
| 09 | Spartan-3 — Video and audio outputs | IC1 |
| 10 | Spartan-3 — Joysticks, PS/2 and serial | IC1 |
| 11 | Spartan-3 — Configuration, control and master clock | IC1 |
| 12 | Spartan-3 — Power, ground and supply bypass | C11, C12, C14, C15, C17, C18, C19, C20, C21, C22, C66, C67, C68, C95, C96, C113, C114, C115, C116, C117, C118, C119, C120, C121, C122, C123, C124, C125, C126, C127, C128, C129, C130, C131, C132, C133, C134, C135, C136, C137, C138, C139, C140, IC1 |
| 13 | Asynchronous SRAM — 6 MiB (1/2) | C54, C55, C56, C57, C147, C148, IC6, IC7, IC14 |
| 14 | Asynchronous SRAM — 6 MiB (2/2) | C50, C51, C52, C53, C145, C146, IC4, IC5, IC13 |
| 15 | MC68000, ARM and storage | |
| 16 | MC68000, supply bypass and bus pull-ups | C46, C47, C48, C49, C101, C107, C108, C109, IC3, R29, R30, R31, R32, R33, R34, R35, R36, R37, R38, R39, R40, R41, R42, R43, R44, R45, R50, R51, R52, R53 |
| 17 | MC68000 bus translation — IC8 to IC12 | C36, C37, C38, C39, C40, C41, C42, C43, C44, C45, IC8, IC9, IC10, IC11, IC12 |
| 18 | AT91SAM7S256, clock and local controls | C70, C71, C72, C73, C75, C77, C79, C80, C81, C82, C83, C84, IC2, R104, R105, R108, R119, R120, R121, S1, SW4, SW5, X1 |
| 19 | ARM USB, boot and microSD | C74, C76, C78, C143, C144, J9, J12, L2, Q1, R100, R101, R102, R103, R106, R107, R110, R112, R114, R115, R116, R117, R118, SW3 |
| 20 | Audio, video and external interfaces | |
| 21 | Stereo audio output | C30, C31, C32, C33, C34, C35, J7, R11, R15, R16, R17, R18 |
| 22 | clock | C58, C59, C60, R79, R80, U2, Y1 |
| 23 | controller | C69, C85, C86, C87, C88, C89, C90, C91, C92, C93, C97, C112, D13, D17, D18, J10, J11, Q4, Q5, Q6, Q7, R23, R24, R25, R26, R27, R28, R46, R47, R135 |
| 24 | joystick | C102, C103, J5, R123, R124, R125, R126, R127, R128, R129, R130, R131, R132, R133, R134 |
| 25 | PS/2 keyboard and mouse | C94, C100, J3, R69, R70, R81, R82, R83, R84 |
| 26 | RS-232 and ESP-01 interfaces | C61, C62, C63, C64, C65, D11, D12, D15, J6, J13, J15, J16, J17, Q8, Q9, Q10, Q11, Q12, Q13, R48, R49, R54, R55, R56, R57, R58, R59, R60, R61, R62, R63, R64, R65, R66, R67, U1 |
| 27 | VGA DAC, sync and supply bypass | C99, C104, C105, C106, C111, D5, D7, D8, D9, D10, J1, R85, R86, R87, R88, R89, R90, R91, R92, R93, R94, R95, R96, R97, R98, SW2 |
| 28 | Mechanical details and board documentation | FID1, FID2, FID3, FID4, FID5, FID6, FID7, FID8, H1, H2, H3, H4 |
| 29 | Top assembly | |
| 30 | Bottom assembly | |
| 31 | Stackup & fabrication | |
| 32 | Routing & impedance | |
| 33 | Power & signal identification |
Preserved. Checked. Documented.
The independent audit passes all 17 preservation checks, including 403 net partitions across 1,623 physical pins, 380 component references and values, and all 208 FPGA pin definitions.
The schematic retains two inherited ERC findings: J12 pin P4 has no output-power driver, and one original wire has an open endpoint. This documentation refresh preserves the circuit and PCB; it does not silently change those source conditions.
A project that travels.
Use the schematic PDFs, manufacturing exports, assembly drawings and interactive BOM for this board revision.