# Rebuilding a 1995 GPS Time Server so I don't get Telstra'd

DevFeed: [Rebuilding a 1995 GPS Time Server so I don't get Telstra'd](<https://devfeed.tech/articles/rebuilding-a-1995-gps-time-server-so-i-don-t-get-telstra-d-10484.md>)

Original publisher: [Read original article](<https://www.jeffgeerling.com/blog/2026/truetime-xl-gps-time-server-restomod/>)

Author: jeff@jeffgeerling.com (Jeff Geerling)

Published: 2026-09-04T14:00:00Z

Content type: article

Language: en

Sources: [Jeff Geerling](<https://devfeed.tech/sources/jeff-geerling.md>)

Topics: [Hardware](<https://devfeed.tech/topics/hardware.md>), [Server](<https://devfeed.tech/topics/server.md>), [configuration](<https://devfeed.tech/topics/configuration.md>), [Network](<https://devfeed.tech/topics/network.md>), [data](<https://devfeed.tech/topics/data.md>)

Tags: [australia](<https://devfeed.tech/tags/australia.md>), [data](<https://devfeed.tech/tags/data.md>), [daytime](<https://devfeed.tech/tags/daytime.md>), [gps](<https://devfeed.tech/tags/gps.md>), [hardware](<https://devfeed.tech/tags/hardware.md>), [network](<https://devfeed.tech/tags/network.md>), [ntp](<https://devfeed.tech/tags/ntp.md>), [raspberry-pi](<https://devfeed.tech/tags/raspberry-pi.md>), [raspberry-pi-5](<https://devfeed.tech/tags/raspberry-pi-5.md>), [server](<https://devfeed.tech/tags/server.md>), [symmetricom](<https://devfeed.tech/tags/symmetricom.md>), [time](<https://devfeed.tech/tags/time.md>), [truetime](<https://devfeed.tech/tags/truetime.md>), [usb](<https://devfeed.tech/tags/usb.md>)

## AI overview

The article documents the restoration of a 1995 TrueTime GPS time server using a Raspberry Pi 5 and GNSS HAT. It explains the hardware integration and configuration of the Pi as a stratum 1 NTP server, including Chrony, LCD and LED status displays, and timing protocols.

## Source excerpt

In June I purchased this TrueTime XL-AK time server, so I could learn more of the history of GPS-based time. I received it on June 22, and just 16 days later a similar GPS time server took down Australia's cell service for 12 hours! I made a short video about it but put off digging into the TrueTime... until now. Over the past couple weeks, I've 'restomodded' this device with a Raspberry Pi, to build a stratum 1 NTP Time server, which I'd like to eventually add to the NTP Pool. I found a way to drop in a Pi 5 and GNSS HAT, display the time and GPS status on the built-in 16x2 LCD, show the status on the bicolor LED, and make this box useful again.