4 layers170.1 × 170.1 mm
4 layers170.1 × 170.1 mm
OtterX
RetroRemake/OtterX408-Bit computer compatible with Commander X16
- Size
- 170.1 × 170.1 mm
- Copper layers
- 4
- Thickness
- 1.58 mm
- Parts
- 188
- Nets
- 233
- Pads
- 1,077
- Tracks, vias
- 4,664, 473
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 19 Apr 2025
- Updated
- 14 Jun 2026
Overview
OtterX is an open-source printed circuit board by RetroRemake, from the RetroRemake/OtterX repository on GitHub, published under the CERN-OHL-W-2.0 licence. It is a 4-layer board of 170.1 × 170.1 mm with 188 parts on 233 nets, routed with 4,664 tracks and 473 vias.
It is built around the ATTINY861-20PU, LM324 and 74AHCT02D, with the 74AHCT273D, 74ACT163PC and 74AHCT00D among its other parts. Its parts include 44 capacitors, 29 diodes, 28 resistors, 18 ICs and 17 connectors. It belongs with the retro computing and games boards and the AVR (ATmega, ATtiny) boards of this library.
Main components
12
ATTINY861-20PU
PDIP-20-40℃~+85℃ 10bit 16 2.7V~5.5V 20MHz 512Byte 512Byte 8 Bit 8KB AVR Built-in FLASH Power-on reset (POR)、Undervoltage detection (BOR/LVD/LVR/LVI)、Watchdog reset、Built-in general-purpose timer、Programmable watchdog、Built-in temperature sensor PDIP-20 Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)
LM324
SOP-14-1.5V~10V 0℃~+70℃ 24V 250nA 3V~20V 4 40mA 50nA 700uA 7mV 80dB SOP-14 Operational Amplifier ROHSHXY MOSFETOperational Amplifier74AHCT02D
SO-14-40℃~+125℃ 100mV、550mV 2 2V 2uA 3.94V、4.4V 4 4.5V~5.5V 7.5ns@5V,50pF 74AHCT Series 800mV 8mA 8mA NOR Gate Overvoltage-tolerant input SO-14 Logic Gates ROHSNexperiaLogic Gates
74AHCT273D
SO-20-300mil3pF 4.5V~5.5V 4uA 74AHCT Series 75MHz 8mA 8mA 9.2ns@5V,50pF D-Type Reset Rising Edge SO-20-300mil Flip Flops ROHSNexperiaFlip Flops
74ACT163PC
PDIP-16-40℃~+85℃ 1 140MHz 4.5V~5.5V 5.5ns@5V,50pF 74ACT Divide-by-2 Reset function、Cascade counter、Synchronous counting Rising Edge Synchronous Synchronous Up Counter PDIP-16 Counters, Dividers ROHSonsemiCounters, Dividers74AHCT00D
SOP-14-40℃~+125℃ 2 2V 2uA 3.7V、4.4V 4 4.5V~5.5V 550mV 7.9ns@5V,50pF 74AHCT Series 800mV 8mA 8mA NAND Gate SOP-14 Logic Gates ROHSNexperiaGates74AHCT04D
SOP-14-40℃~+125℃ 2V 4.5V~5.5V 4.5ns@5V,50pF 40uA 6 74AHCT 800mV SOP-14 Inverters ROHSNexperiaInverters
74AHCT138D
SO-16-40℃~+125℃ 3/8 4.5V~5.5V 6.2ns@5V,50pF 74AHCT 80uA 8mA 8mA Decoder Single Supply SO-16 Signal Switches, Multiplexers, Decoders ROHSNexperiaSignal Switches, Multiplexers, Decoders74AHCT32D
SO-14-40℃~+125℃ 2V 2uA 4 4.5V~5.5V 7.9ns@5V,50pF 74AHCT Series 800mV 8mA 8mA OR Gate SO-14 Logic Gates ROHSNexperiaGates
AS6C1008-55PCN
PDIP-320℃~+70℃ 1Mbit 1uA 2.7V~5.5V 55ns 60mA PDIP-32 SRAM ROHSAlliance MemorySRAM
AS6C4008-55PCN
PDIP-320℃~+70℃ 2.7V~5.5V 30mA 4Mbit 4uA 55ns Parallel Port (Parallel) PDIP-32 SRAM ROHSAlliance MemorySRAM
P4KE6.8CA
DO-41-55℃~+150℃ 10.5V 1mA 38.1A 400W@10/1000us 5.8V 6.46V Bidirectional TVS DO-41 ESD and Surge Protection (TVS/ESD) ROHSDOWOESD And Surge Protection (TVS/ESD)
README
README.mdOtterX
An Open Source 6502-based, Commander X16-compatible, 8-bit Computer
Where to buy?
Looking to order and build your own OtterX? Official kits are available from:
Parts
188| Qty | Value | Footprint | References |
|---|---|---|---|
| 26 | 0.1u | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C1, C2, C3, C4, C10, C12, C21, C22, C23, C24, C25, C26, C27, C28, C29, C41 +10 |
| 15 | P4KE6.8CA | Diode_THT:D_DO-41_SOD81_P7.62mm_Horizontal | D1, D11, D12, D16, D17, D20, D21, D22, D23, D24, D25, D26, D27, D28, D29 |
| 10 | 1K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R2, R4, R5, R6, R30, R31, R32, R33, R34 |
| 6 | 10K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R9, R11, R16, R17, R19, R20 |
| 6 | 1N4148 | Diode_THT:D_DO-34_SOD68_P7.62mm_Horizontal | D3, D6, D7, D8, D9, D10 |
| 6 | 330p | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C13, C14, C15, C18, C19, C20 |
| 4 | 10u | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C51, C52, C53, C57 |
| 4 | 15K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R15, R18, R21, R22 |
| 4 | 1N4148 | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | D13, D14, D15, D19 |
| 4 | MountingHole | MountingHole:MountingHole_3.2mm_M3 | H1, H2, H3, H4 |
| 4 | MountingHole | MountingHole:MountingHole_4.3mm_M4 | H5, H6, H7, H8 |
| 3 | 100R | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R23, R24, R27 |
| 3 | 2N7000 | Package_TO_SOT_THT:TO-92_Inline | Q1, Q2, Q3 |
| 3 | FSM4JH | OtterX:Tactile Switch Dual | SW1, SW2, SW3 |
| 2 | 1n | Capacitor_THT:C_Rect_L7.2mm_W2.5mm_P5.00mm_FKS2_FKP2_MKS2_MKP2 | C42, C43 |
| 2 | 2.2u | Capacitor_THT:C_Rect_L10.3mm_W5.7mm_P7.50mm_MKS4 | C46, C47 |
| 2 | 2K2 | Resistor_THT:R_Array_SIP7 | RN1, RN6 |
| 2 | 2K2 | Resistor_THT:R_Array_SIP5 | RN2, RN3 |
| 2 | 3.3n | Capacitor_THT:C_Rect_L7.2mm_W2.5mm_P5.00mm_FKS2_FKP2_MKS2_MKP2 | C55, C56 |
| 2 | 3p | Capacitor_THT:C_Disc_D3.8mm_W2.6mm_P2.50mm | C16, C17 |
| 2 | 560 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R7, R8 |
| 2 | 74AHCT02 | OtterX:DIP-14_W7.62mm_ShortWidePads | U15, U17 |
| 2 | 74AHCT20 | OtterX:DIP-14_W7.62mm_ShortWidePads | U19, U20 |
| 2 | 74AHCT273 | OtterX:DIP-20_W7.62mm_ShortWidePads | U5, U6 |
| 2 | FerriteBead_Small | Inductor_THT:L_Axial_L5.0mm_D3.6mm_P10.00mm_Horizontal_Murata_BL01RN1A2A2 | FB1, FB2 |
| 1 | 1.5MB RAM Expansion | Connector_PinSocket_2.00mm:PinSocket_2x20_P2.00mm_Vertical | J10 |
| 1 | 1N5819 | Diode_THT:D_DO-34_SOD68_P7.62mm_Horizontal | D2 |
| 1 | 2K2 | Resistor_THT:R_Array_SIP8 | RN5 |
| 1 | 2K2 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R3 |
| 1 | 390R | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R29 |
| 1 | 470uH | Inductor_THT:L_Axial_L5.0mm_D3.6mm_P10.00mm_Horizontal_Murata_BL01RN1A2A2 | L1 |
| 1 | 560R | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R28 |
| 1 | 60 Pin Edge Conn | OtterX:TE155308438 | P1 |
| 1 | 74ACT163 | OtterX:DIP-16_W7.62mm_ShortWidePads | U11 |
| 1 | 74AHCT00 | OtterX:DIP-14_W7.62mm_ShortWidePads | U14 |
| 1 | 74AHCT04 | OtterX:DIP-14_W7.62mm_ShortWidePads | U16 |
| 1 | 74AHCT10 | OtterX:DIP-14_W7.62mm_ShortWidePads | U4 |
| 1 | 74AHCT138 | OtterX:DIP-16_W7.62mm_ShortWidePads | U21 |
| 1 | 74AHCT32 | OtterX:DIP-14_W7.62mm_ShortWidePads | U18 |
| 1 | 74LS06 | OtterX:DIP-14_W7.62mm_ShortWidePads | U3 |
| 1 | ACH-16.000MHZ-EK | Oscillator:Oscillator_DIP-8 | X1 |
| 1 | ACT LED Bypass | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP7 |
| 1 | AS6C1008-55PCN | OtterX:DIP-32_W15.24mm_ShortWidePads | U8 |
| 1 | AS6C4008-55PCN | OtterX:DIP-32_W15.24mm_ShortWidePads | U9 |
| 1 | ATX-24 | OtterX:1-1775099-3-Fixed | J16 |
| 1 | ATtiny861-20P | OtterX:DIP-20_W7.62mm_ShortWidePads | U12 |
| 1 | Act LED Disable | Jumper:SolderJumper-2_P1.3mm_Bridged_Pad1.0x1.5mm | JP6 |
| 1 | AudioPlug3 | Connector_Audio:Jack_3.5mm_CUI_SJ1-3525N_Horizontal | J29 |
| 1 | BAT-HLD-001-THM | OtterX:CELL_BATT_CLIP | BT1 |
| 1 | ECS-.327-6-13X | Crystal:Crystal_DS26_D2.0mm_L6.0mm_Horizontal | Y1 |
| 1 | ECS-2100AX-3.579545MHZ | Oscillator:Oscillator_DIP-8 | X2 |
| 1 | EXTRAM_ENABLE | Connector_PinHeader_2.00mm:PinHeader_1x03_P2.00mm_Vertical | J27 |
| 1 | Ext. NMI | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J6 |
| 1 | Flash WR EN | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J14 |
| 1 | Front Panel | Connector_PinHeader_2.54mm:PinHeader_2x05_P2.54mm_Vertical | J26 |
| 1 | HK19F | OtterX:HK19F-DPDT-Relay | K1 |
| 1 | I2C | Connector_JST:JST_PH_B4B-PH-K_1x04_P2.00mm_Vertical | J9 |
| 1 | IO3 Clk Stretch | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP12 |
| 1 | ISP | Connector_IDC:IDC-Header_2x03_P2.54mm_Vertical | J21 |
| 1 | JK30 | Fuse:Fuse_Bourns_MF-RG400 | F1 |
| 1 | KMDGX-6SG | OtterX:Kycon KMDGX-6SG P-S4N | J11 |
| 1 | LED_GRN | LED_THT:LED_D3.0mm | D4 |
| 1 | LED_RED | LED_THT:LED_D3.0mm | D18 |
| 1 | LED_YEL | LED_THT:LED_D3.0mm | D5 |
| 1 | LM324 | OtterX:DIP-14_W7.62mm_ShortWidePads | U26 |
| 1 | LOGO | OtterX:Fancy_X_FCu | G*** |
| 1 | LOGO | OtterX:Fancy_X_Mask | G*** |
| 1 | MCP7940N-xP | Package_DIP:DIP-8_W7.62mm | U13 |
| 1 | PS2 Pwr Src | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J25 |
| 1 | Pow LED Disable | Jumper:SolderJumper-2_P1.3mm_Bridged_Pad1.0x1.5mm | JP5 |
| 1 | RTC GPIO | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J7 |
| 1 | RXEF010 | Fuse:Fuse_Bourns_MF-RG400 | F5 |
| 1 | RXEF025 | Fuse:Fuse_Bourns_MF-RG300 | F4 |
| 1 | RXEF110 | Fuse:Fuse_Bourns_MF-RG400 | F3 |
| 1 | SBY LED Disable | Jumper:SolderJumper-2_P1.3mm_Bridged_Pad1.0x1.5mm | JP3 |
| 1 | SDF-60J | OtterX:SDF60J | J24 |
| 1 | SMC Alarm | Jumper:SolderJumper-2_P1.3mm_Bridged_Pad1.0x1.5mm | JP8 |
| 1 | SNES0 | OtterX:SNES_L | J18 |
| 1 | SNES1 | OtterX:SNES_R | J19 |
| 1 | SNES23 | Connector_PinSocket_2.54mm:PinSocket_2x03_P2.54mm_Vertical | J17 |
The 175 most common of 188 parts.
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Questions
How big is the OtterX PCB?
It measures 170.1 × 170.1 mm and has 4 copper layers, 1.58 mm thick.
What parts does the OtterX use?
188 parts, built around the ATTINY861-20PU, LM324, 74AHCT02D and 74AHCT273D. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the OtterX KiCad files?
From the RetroRemake/OtterX repository on GitHub, at the commit this page was made from: the board is Sirius_DV1/OtterX.kicad_pcb and its schematic BodgeBoard/BodgeBoard.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the OtterX design in my own project?
Its repository publishes it under the CERN-OHL-W-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).