Voltmeter C64/C128/VIC-20

Commodore C64/C128/VIC-20 Voltmeter by Electroware — complete 5 V DC rail meter compatible with C64, C128 and VIC-20 computers

This is the ideal add-on for Electroware adjustable PSU models (the PRO line and standard units upgraded with the Adjust & Protect module). See live 5 V readings while trimming your PSU — without opening the computer or probing pins with a multimeter. Just plug in, adjust, done.

Stay original! Choose genuine C64PSU.com gear — avoid overrated clones.

Commodore C64/C128/VIC-20 voltmeter device by Electroware

Our voltmeter is a complete 5 V DC rail meter compatible with Commodore C64, C128 and VIC-20. Unlike PSU-side OLED readouts that always show a fixed “5.01 V”, this tool measures the voltage where it matters — on the computer mainboard, after the cable and power switch drop (which vary by model and unit). Accurate, repeatable, factory-calibrated, and ready to use via the CN2 cassette/Datasette port.

HOW TO USE IT?

Plug the device into the CN2 cassette/Datasette port. The pass-through connector preserves all signals so you can keep your Datasette connected inline. A bright LED display shows the voltage clearly and can be switched off to keep your retro setup dim. Each unit is factory-calibrated against a precision reference. If you ever need to re-calibrate, a trim potentiometer is accessible through a small hole on the back.

It’s the perfect companion for Electroware adjustable PSUs, letting you watch the live 5 V rail while you trim the output. No more juggling a multimeter and a screwdriver at once — simply adjust the PSU to the recommended 5.00 V at the mainboard and protect key chips like SID, PLA and CPU from over-/undervoltage.

UNIQUE FEATURES & QUALITY

Choose genuine Electroware for build quality and user-focused features you won’t find in clones:

• ON/OFF switch — see voltage when needed; switch off when not, without unplugging
• Factory pre-calibrated with 5 V reference for accurate, repeatable readings
• Bright, clear LED display (green) with optional display-off
• Pass-through (inline) design — does not block the cassette/Datasette port
• Elegant form factor, durable enclosure suited for daily bench use
• Evolved from our in-house tooling used for extended PSU testing to make adjustments faster and safer

TRUST & RESPONSIBILITY

Every Electroware voltmeter is triple-tested before dispatch. For long-term reliability, we verify each unit with original Commodore hardware from our collection.

Stay genuine — Electroware products deliver build quality and features developed specifically for the Commodore 8-bit community.

By choosing this product you support the global C= community and help us keep developing dependable tools for your classic machines. Thank you!

Stay original! Choose genuine C64PSU.com gear and beware of clones flooding eBay & the web.