Coco salt replacement
About the Coco salt replacement PCB
Coco salt replacement is an open source PCB design by qbancoffee, published on GitHub under the GPL-3.0 license. It is a 2-layer board measuring 27.6 × 34.3 mm, with 20 components from 14 distinct parts.
Other key parts include the LM2596SX-5.0/NOPB, MAX3232EUE+T and LM393DR2G. By type, the board carries 8 resistors, 4 capacitors, 3 ICs, 2 diodes, 1 transistor and 1 connector.
From the project
- Installation instructions - View PDF version of the schematic - Download the latest release - How to order from JLCPCB - Peppers in the wild
- Installation instructions - View PDF version of the schematic - Download the latest release - How to order from JLCPCB - Peppers in the wild
This board replaces the functionality of the SALT chip in the CoCo (CoCo 2 in my case). The SALT chip (Supply and Level Translator) is responsible for supply regulation, RS-232 interface, level translation, cassette read operations, and driving the cassette relay.
Main components on the Coco salt replacement
Coco salt replacement bill of materials (BOM)
20 components, 14 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | LM2596SX-5.0/NOPB LM2596S-5 LCSC | TO-263-5_TabPin3 | U1 |
| 1 | MAX3232EUE+T MAX3232 LCSC | TSSOP-16-1EP_4.4x5mm_P0.65mm | U2 |
| 1 | LM393DR2G LM393 JLCPCB | SOIC-8_3.9x4.9mm_P1.27mm | U3 |
| 1 | MMBT9014C LCSC | SOT-23 | Q1 |
| 1 | SALT chip package pins DNI | DIP-16_W7.62mm_Socket | J1 |
| 1 | SS54 5A 40V JLCPCB | D_SMA | D1 |
| 1 | 1N4148WS JLCPCB | D_SOD-323 | D2 |
| 1 | YSPI0740-330M 33uH LSCSC | L_Sumida_CDMC6D28_7.25x6.5mm | L1 |
| 1 | C1005X7R1H104KT000F .1uF JLCPCB | C_0402_1005Metric | C6 |
| 3 | CL10B474KA8NNNC .47uF LCSC | C_0603_1608Metric | C7, C8, C9 |
| 2 | 0402WGF1003TCE 100K LCSC | R_0402_1005Metric | R1, R3 |
| 2 | 0402WGF1002TCE 10K LCSC | R_0402_1005Metric | R2, R8 |
| 3 | 0402WGF5101TCE 5.1K LCSC | R_0402_1005Metric | R4, R5, R6 |
| 1 | 0402WGJ0206TCE 20M LCSC | R_0402_1005Metric | R7 |
Coco salt replacement design files
The KiCad project lives in the qbancoffee/coco_salt_replacement repository on GitHub; these links point at the commit this page was built from.
Coco salt replacement: common questions
How big is the Coco salt replacement PCB?
The Coco salt replacement measures 27.6 × 34.3 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Coco salt replacement?
20 components, from 14 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the Coco salt replacement design files?
From the qbancoffee/coco_salt_replacement repository on GitHub, which has the KiCad layout and the BOM; the links under Design files point to each one.
Can I use the Coco salt replacement design in my own project?
Yes, under the terms of its GPL-3.0 license, which qbancoffee chose for the repository.