Vintage DRAM Tester for 15 different RAM Types

Fast, open-source DRAM tester for retro computers – C64, C128, Amiga, Atari, ZX Spectrum, BBC Micro, Apple IIe and many more. Built around an ATmega328P, tests memory thoroughly in seconds.

Over 200 units sold worldwide. As featured on:

• Adrian's Digital Basement (May 2026): Mail Call #5 – 25 min hands-on: "This is freaking awesome"
• Hackaday (Dec 2025): "Cheap and Aggressive DRAM Chip Tester"
• Elektor Magazine (Dec 2025): "Ram-Tester Is an Open-Source DIY Solution for Retro Computer RAM"

Why this tester?

• No chip knowledge needed – Set the pin count via DIP switch — the tester auto-detects the chip type. No deciphering chip markings, no menus, no datasheet lookups. Grab a chip from the parts bin, plug it in, get a result.
• Fast – Most tests complete in under 10 seconds. Full 41256 test in 7.4s. Test a whole tray in minutes, not hours.
• Thorough – Patterns, crosstalk, address line verification, retention time, CAS-Before-RAS refresh, fast page mode, static column, nibble mode, ground short detection.
• Practical – Clear good/bad result. A DRAM chip can't be repaired – you need to know if it works, not why it doesn't.
• Safe – Short-circuit protection, current limiting, ground short detection. Self-test mode included.
• Fully Open Source – Hardware, firmware, schematics on GitHub. No black box, no vendor lock-in.

How it works

1. Insert the chip (16, 18 or 20 pins, DIP or ZIP).
2. Set the DIP switch to match the pin count.
3. Connect USB-C power (or press RESET if already powered).
4. Read the result: OLED display shows a plain-text report, or LED blink codes (green = pass, red = fail).

Supported chips & test times

Test times include OLED display. Without display approx. 1s shorter. Full compatibility list: compatibility.md on GitHub

What's in the box

• Pre-assembled V3 PCB with all SMD parts soldered
• Programmed and tested microcontroller with latest firmware
• All parts to complete the tester (ZIF socket, OLED display, DIP switch, ZIP sockets)
• Instruction leaflet with self-adhesive foam pad for the finished PCB

Product options:

• RAM Tester Only – Complete kit for all supported RAMs except 4027/4116
• with 4116 Adapter – RAM Tester + 4027/4116 adapter board kit
• 4116 Adapter Only – Requires RAM Tester with firmware ≥ 3.x.x

What you need

• Soldering iron (50 solder points, +36 for 4116 adapter)
• USB-C power supply (5V, 1A) with cable
• Assembly video and docs on GitHub

Shipping

• Switzerland: Swiss Post Economy.
• Europe: Swiss Post Economy. Import duties handled by Lectronz - no additional fees on delivery
• USA: Swiss Post PDDP (Delivered Duty Paid) – all import duties prepaid. NO additional fees on delivery.
• Rest of World: Check your country's import regulations regarding import fees.

Ships within 2–3 business days from Switzerland.

⚠ Laboratory / Maker Kit – Not a consumer product. Open-source kit, sold as-is. Operate only with certified USB-C power supply. Not for unattended use.

Voluntary take-back: Devices may be returned to the developer for recycling. Shipping costs borne by sender. No WEEE scheme participation.