6 layers300 × 248.8 mm
2 layers97.8 × 81.3 mm
TR4org ROM
nanamitm/TR4org-ROMStandalone KiCad 10 project for the external ROM board used with the TR4org TD4 4-bit CPU reproduction. The schematic implements a jumper-programmed 16 x 8 diode-matrix ROM.
- Size
- 97.8 × 81.3 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 221
- Nets
- 199
- Pads
- 727
- Tracks, vias
- 1,672, 94
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 27 Jul 2026
- Updated
- 30 Jul 2026
Overview
TR4org ROM is an open-source printed circuit board by nanamitm, from the nanamitm/TR4org-ROM repository on GitHub. It is a 2-layer board of 97.8 × 81.3 mm with 221 parts on 199 nets, routed with 1,672 tracks and 94 vias.
It is built around the SN74HC04DR, SN74HC138DR(LX) and 1N4148WS, with the XL-1608UYC-06, XL-1608UGC-04 and CC0603KRX7R9BB104 among its other parts. Its parts include 156 diodes, 36 resistors, 4 capacitors, 4 ICs and 1 connector.
Main components
6
SN74HC04DR
SOIC-14-40℃~+85℃ 1 1.5V~4.2V 1.9V、4.4V、5.9V 100mV、100mV、100mV 16ns@6V,50pF 2V~6V 2uA 5.2mA 5.2mA 500mV~1.8V 6 74HC SOIC-14 Inverters ROHSTexas InstrumentsInverters
SN74HC138DR(LX)
SOP-16-40℃~+105℃ 15ns@4.5V,15pF 2V~6V 3/8 5.2mA 74HC 8uA Decoder Single Supply SOP-16 Signal Switches, Multiplexers, Decoders ROHSlingxingicSignal Switches, Multiplexers, Decoders
1N4148WS
SOD-3231.25V@150mA 100V 150mA 1uA@75V 200mW 2A 4ns Independent SOD-323 Switching Diodes ROHSJiangsu Changjing Electronics Technology (CJ)Switching Diodes
XL-1608UYC-06
0603-40℃~+85℃ 120° 2.4V 20mA 435mcd 50mW 585nm~595nm 590nm Discrete Diode Top-mount Water Clear Yellow 0603 LED Indication - Discrete ROHSXINGLIGHTLED Indication - DiscreteXL-1608UGC-04
0603-40℃~+85℃ 120° 20mA 3.3V 515nm~535nm 525nm 70mW 810mcd Discrete Diode Emerald Green Top-mount Water Clear 0603 LED Indication - Discrete ROHSXINGLIGHTLED Indication - Discrete
CC0603KRX7R9BB104
0603100nF 50V X7R ±10% 0603 Multilayer Ceramic Capacitors MLCC - SMD/SMT ROHSYAGEOMultilayer Ceramic Capacitors MLCC - SMD/SMT
README
README.mdTR4org-ROM
Standalone KiCad 10 project for the external ROM board used with the TR4org TD4 4-bit CPU reproduction. The schematic implements a jumper-programmed 16 x 8 diode-matrix ROM.
The circuit is reproduced from the original TD4 design by M. Yamamoto
(xyama.sakura.ne.jp). See the schematic title block for the source
attribution.
Project layout
| Path | Purpose |
|---|---|
TR4org-ROM.kicad_pro | KiCad project settings |
TR4org-ROM.kicad_sch | ROM schematic |
TR4org-ROM.kicad_pcb | PCB layout |
lib/TD4.kicad_sym | Project-local custom symbol library |
sym-lib-table | Library table using ${KIPRJMOD}-relative paths |
manufacturing/jlcpcb/gerber/ | Gerber and drill files for fabrication |
manufacturing/jlcpcb/production_files/ | JLCPCB BOM, CPL, and ready-to-upload Gerber archive |
TR4org-ROM-backups/, *.kicad_prl, and
manufacturing/jlcpcb/project.db are local KiCad/tool state and are not
intended for version control.
Main-board connection
J2 is the ROM-board interface: a vertical 1 x 15, 2.54 mm pin header. It
mates with the 1 x 15, 2.54 mm pin socket labelled EX CONN (ROM) on the
TR4org main board.
Opening the project
Open TR4org-ROM.kicad_pro with KiCad 10. The custom TD4 library resolves
from lib/TD4.kicad_sym; no absolute library paths are required.
Fabrication data
The JLCPCB fabrication package is kept under manufacturing/jlcpcb/. Before
placing an order, regenerate it from the current PCB after running ERC and DRC,
then review the BOM, CPL, and Gerber archive.
License
No license has been selected for this repository yet. Choose and add an appropriate license before making the project public.
Parts
221| Qty | Value | Footprint | References |
|---|---|---|---|
| 128 | 1N4148WS | Diode_SMD:D_SOD-323 | D1, D10, D11, D100, D101, D102, D103, D104, D105, D106, D107, D108, D109, D110, D111, D112 +112 |
| 28 | 1k | Resistor_SMD:R_0603_1608Metric | R1, R2, R3, R10, R11, R12, R13, R14, R15, R16, R25, R26, R27, R28, R29, R30 +12 |
| 20 | Yellow | LED_SMD:LED_0603_1608Metric | D65, D66, D67, D68, D137, D138, D139, D140, D141, D142, D143, D144, D153, D154, D155, D156 +4 |
| 8 | 10k | Resistor_SMD:R_0603_1608Metric | R17, R18, R19, R20, R21, R22, R23, R24 |
| 8 | Green | LED_SMD:LED_0603_1608Metric | D145, D146, D147, D148, D149, D150, D151, D152 |
| 4 | 100n | Capacitor_SMD:C_0603_1608Metric | C1, C2, C3, C4 |
| 4 | MountingHole | MountingHole:MountingHole_2.2mm_M2 | H1, H2, H3, H4 |
| 2 | SN74HC04DR | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U1, U4 |
| 2 | SN74HC138DR | Package_SO:SOIC-16_3.9x9.9mm_P1.27mm | U2, U3 |
| 1 | EX CONN | Connector_PinHeader_2.54mm:PinHeader_1x15_P2.54mm_Vertical | J1 |
| 1 | ROM00 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP1 |
| 1 | ROM01 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP2 |
| 1 | ROM02 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP3 |
| 1 | ROM03 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP4 |
| 1 | ROM04 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP5 |
| 1 | ROM05 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP6 |
| 1 | ROM06 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP7 |
| 1 | ROM07 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP8 |
| 1 | ROM08 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP9 |
| 1 | ROM09 | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP10 |
| 1 | ROM0A | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP11 |
| 1 | ROM0B | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP12 |
| 1 | ROM0C | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP13 |
| 1 | ROM0D | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP14 |
| 1 | ROM0E | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP15 |
| 1 | ROM0F | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | JP16 |
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Questions
How big is the TR4org ROM PCB?
It measures 97.8 × 81.3 mm and has 2 copper layers, 1.6 mm thick.
What parts does the TR4org ROM use?
221 parts, built around the SN74HC04DR, SN74HC138DR(LX), 1N4148WS and XL-1608UYC-06. 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 TR4org ROM KiCad files?
From the nanamitm/TR4org-ROM repository on GitHub, at the commit this page was made from: the board is TR4org-ROM.kicad_pcb and its schematic TR4org-ROM.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the TR4org ROM design in my own project?
Its repository states no licence, so its author keeps all rights: ask nanamitm before reusing the design.