4 layers55 × 50 mm
2 layers101.6 × 53.3 mm
Interface1
lowobservable/coax53Connect to IBM 3270 hardware
- Size
- 101.6 × 53.3 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 18
- Nets
- 41
- Pads
- 188
- Tracks, vias
- 333, 5
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 5 (file 20171130)
- Created
- 27 Jun 2019
- Updated
- 8 Feb 2026
Overview
Interface1 is an open-source printed circuit board by lowobservable, from the lowobservable/coax repository on GitHub, published under the ISC licence. It is a 2-layer board of 101.6 × 53.3 mm with 18 parts on 41 nets, routed with 333 tracks and 5 vias.
It is built around the DP8340N, DP8341N and DS3487N. Its parts include 7 resistors, 4 capacitors, 3 ICs, 1 connector and 1 crystal. It belongs with the AVR (ATmega, ATtiny) boards of this library.
Main components
3
DP8340N
DIP-24DIP-24 Microcontrollers (MCU/MPU/SOC)Texas InstrumentsMicrocontrollers (MCU/MPU/SOC)DP8341N
DIP-24DIP-24 Microcontrollers (MCU/MPU/SOC)Texas InstrumentsMicrocontrollers (MCU/MPU/SOC)
DS3487N
DIP-16-40℃~+85℃ 0 4 4.75V~5.25V Driver Enable shutdown DIP-16 RS-485 / RS-422 ICs ROHSHGSEMIRS-485 / RS-422 ICs
README
README.mdcoax
Tools for connecting to real IBM 3270 type terminals.
Documentation
- protocol - Protocol documentation
Hardware
- interface1 - Legacy interface using obsolete National Semiconductor DP8340 and DP8341
- interface2 - Modern interface using a Lattice iCE40 FPGA and STM32 microcontroller
Software
- pycoax - Python interface library
See Also
- oec - IBM 3270 terminal controller (a replacement for the IBM 3174)
Parts
18| Qty | Value | Footprint | References |
|---|---|---|---|
| 3 | 0.1 uF | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm | C2, C3, C4 |
| 2 | 150 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R5 |
| 2 | 33 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R2, R4 |
| 1 | 120 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R6 |
| 1 | 30 pF | Capacitor_THT:C_Disc_D9.0mm_W5.0mm_P7.50mm | C1 |
| 1 | 500 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R7 |
| 1 | 510 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R3 |
| 1 | Arduino_Mega2560_Shield | arduino:Arduino_Mega2560_Shield | XA1 |
| 1 | Crystal | Crystal:Crystal_SMD_HC49-SD | Y1 |
| 1 | DP8340 | Package_DIP:DIP-24_W15.24mm_Socket | U1 |
| 1 | DP8341 | Package_DIP:DIP-24_W15.24mm_Socket | U2 |
| 1 | DS3487 | Package_DIP:DIP-16_W7.62mm | U3 |
| 1 | PE-5762 | library:PE_TH6 | T1 |
| 1 | RG62 | Connector_Coaxial:BNC_Amphenol_B6252HB-NPP3G-50_Horizontal | J1 |
Questions
How big is the Interface1 PCB?
It measures 101.6 × 53.3 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Interface1 use?
18 parts, built around the DP8340N, DP8341N and DS3487N. 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 Interface1 KiCad files?
From the lowobservable/coax repository on GitHub, at the commit this page was made from: the board is interface1/hardware/hardware.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Interface1 design in my own project?
Its repository publishes it under the ISC licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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