2 layers177.8 × 130.8 mm
2 layers99.1 × 69.9 mm
FC UNROM512-PRGRAM
ponchick/FC-UNROM512-PRGRAM3UNROM512 + PRG RAM Famicom cartridge PCB
- Size
- 99.1 × 69.9 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 35
- Nets
- 89
- Pads
- 305
- Tracks, vias
- 900, 48
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 1 May 2026
- Updated
- 1 May 2026
Overview
FC UNROM512-PRGRAM is an open-source printed circuit board by ponchick, from the ponchick/FC-UNROM512-PRGRAM repository on GitHub, published under the CERN-OHL-P-2.0 licence. It is a 2-layer board of 99.1 × 69.9 mm with 35 parts on 89 nets, routed with 900 tracks and 48 vias.
It is built around the 74HC32D, 74HC139D and 74HC20D, with the 74HC377D and BAT85 among its other parts. Its parts include 8 ICs, 7 capacitors, 2 resistors, 2 diodes and 1 transistor. It belongs with the retro computing and games boards of this library.
Main components
5
74HC32D
SOP-14-40℃~+125℃ 1.5V~4.2V 1.9V、4.4V、5.9V 100mV、400mV、400mV 2 2V~6V 2uA 4 5.2mA 5.2mA 500mV~1.8V 6ns@6V,50pF 74HC Series OR Gate SOIC-14 Logic Gates ROHSNexperiaLogic Gates
74HC139D
SO-16-40℃~+125℃ 11ns@6.0V,50pF 160uA 2/4 2V~6V 74HC Decoder Single Supply SOIC-16 Signal Switches, Multiplexers, Decoders ROHSNexperiaSignal Switches / Encoders & Decoders / Multiplexers74HC20D
SOP-14-40℃~+125℃ 1.5V~4.2V 100mV、400mV、400mV 15ns@6V,50pF 2 2V~6V 2uA 4 5.2mA 5.2mA 500mV~1.8V 74HC Series NAND Gate SOP-14 Logic Gates ROHSNexperiaGates
74HC377D
SO-20-300mil-40℃~+125℃ 1 12ns 16ns@4.5V,50pF 2V~6V 3.5pF 3ns 4mA 4mA 74HC Series 77MHz 8 8uA D-Type Enable Rising Edge SOIC-20-300mil Flip Flops ROHSNexperiaFlip Flops
BAT85
DO-341 Independent 200mA 2uA@25V 30V 5A 800mV@100mA DO-34 Schottky Diodes ROHSNexperiaSchottky Diodes
README
README.mdFC-UNROM512
UNROM512 Famicom cartridge PCB (UNROM/UOROM family, extended PRG-ROM bank switching) with additional PRG RAM.
Russian version: README.ru.md
More details about UNROM512 format and compatibility:
Jumpers (board configuration)
1) Flash memory mode (write protection / self-flashing)
| Configuration | FL1-FL4 | FLASHABLE | 74*139 | Bus conflicts |
|---|---|---|---|---|
| Not Flashable (write-protected) | Closed | Open | Not installed | Present |
| Flashable (self-flashable) | Open | Closed | Installed | Absent |
2) Mirroring
Mirroring must match the ROM you are programming. The game expects a specific mode (vertical/horizontal/1-screen). A wrong setting causes visual glitches.
Only one of these jumpers should be closed. For Vertical mirroring, close VERT and keep HORIZ and ONE open.
3) CHR RAM size configuration (8/16/32 KiB)
The actual CHR RAM size is defined by the physical RAM chip (for example, 62256 = 32 KiB). Jumpers only route the required address lines.
| Size | 8k | 8k/16k | 16k/32k | 32k |
|---|---|---|---|---|
| 8 KiB | Closed | Closed | Open | Open |
| 16 KiB | Open | Closed | Closed | Open |
| 32 KiB | Open | Open | Closed | Closed |
Use smaller CHR RAM sizes (8/16 KiB) only if the target ROM explicitly supports them. Most UNROM512 / Mapper 30 software expects 32 KiB. Forcing a smaller size on unsupported ROMs can cause errors.
License
This project is licensed under CERN Open Hardware Licence Version 2 - Permissive (CERN-OHL-P-2.0), see LICENSE.
SPDX-License-Identifier: CERN-OHL-P-2.0
Parts
35| Qty | Value | Footprint | References |
|---|---|---|---|
| 5 | 0.1u | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C1, C2, C3, C4, C5 |
| 2 | 74HC32 | Package_DIP:DIP-14_W7.62mm | U3, U5 |
| 2 | BAT85 | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | D1, D2 |
| 1 | 100k | Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal | R1 |
| 1 | 10u | Capacitor_THT:CP_Radial_D4.0mm_P2.00mm | C7 |
| 1 | 16k/32k | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP11 |
| 1 | 1k | Resistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal | R2 |
| 1 | 1n | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C6 |
| 1 | 2032 | Battery:BatteryHolder_Keystone_1060_1x2032 | BT1 |
| 1 | 2N3904 | Package_TO_SOT_THT:TO-92_Inline_Wide | Q1 |
| 1 | 32k | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP12 |
| 1 | 74HC139 | Package_DIP:DIP-16_W7.62mm | U6 |
| 1 | 74HC20 | Package_DIP:DIP-14_W7.62mm | U8 |
| 1 | 74HC377 | Package_DIP:DIP-20_W7.62mm | U4 |
| 1 | 8k | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP9 |
| 1 | 8k/16k | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP10 |
| 1 | CHR RAM | Cart:DIP-28_Dual | U2 |
| 1 | FAMICOM_EDGE | Cart:CONN_EDGE_2x60 | J1 |
| 1 | FL1 | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP1 |
| 1 | FL2 | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP2 |
| 1 | FL3 | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP3 |
| 1 | FL4 | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP4 |
| 1 | FLASHABLE | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP5 |
| 1 | HORIZ | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP8 |
| 1 | LOGO | 0-Logo:ponchick | LOGO# |
| 1 | ONE | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP6 |
| 1 | PRG RAM | Cart:DIP-28_Dual | U7 |
| 1 | PRG ROM | Package_DIP:DIP-32_W15.24mm_Socket | U1 |
| 1 | VERT | Jumper:SolderJumper-2_P1.3mm_Open_Pad1.0x1.5mm | JP7 |
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Questions
How big is the FC UNROM512-PRGRAM PCB?
It measures 99.1 × 69.9 mm and has 2 copper layers, 1.6 mm thick.
What parts does the FC UNROM512-PRGRAM use?
35 parts, built around the 74HC32D, 74HC139D, 74HC20D and 74HC377D. 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 FC UNROM512-PRGRAM KiCad files?
From the ponchick/FC-UNROM512-PRGRAM repository on GitHub, at the commit this page was made from: the board is FC-UNROM512-PRGRAM.kicad_pcb and its schematic FC-UNROM512-PRGRAM.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the FC UNROM512-PRGRAM design in my own project?
Its repository publishes it under the CERN-OHL-P-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).