Mark Jelic Rings in 40 Years Since the TEC-1 Launch with a New, Open Source, Upgraded TEC-1G SBC

UPDATE (12/14/2023): Mark Jelic has turned his design for an upgraded Talking Electronics TEC-1 kit-computer into a purchasable product, either as a bare PCB to be populated by the buyer or as a full kit of parts requiring only to be soldered together.

The PCB, which takes a design now 40 years old and makes a range of tweaks and quality-of-life improvements including a better keypad and integrated display, is priced at $20; the full kit starts at $165 with no keyboard keys rising to $202.50 with Fullsik mechanical switches, under-key LED lighting, and keycaps bundled.

All versions are available to order now on Jelic's Tindie store.

Original article continues below.

Vintage computing enthusiast Mark Jelic is celebrating 40 years since the launch of Talking Electronics' TEC-1 single-board computer (SBC) in style — by identifying the limitations of the original and fixing them.

"The TEC-1 […] was first published by the Australian electronics hobbyist magazine 'Talking Electronics' between 1981 and 1991," Jelic explains of the original device. "The TEC-1 was developed as a learning computer, designed to teach the basics of how a microprocessor works at the fundamental hardware and software level, and offered the ability to create and run simple programs in Z80 machine code. TE magazine covered the TEC-1 in six installments from Issue 10 to 15."

Teaming up with the TEC-1's original designers John Hardy and Ken Stone, as well as former Talking Electronics staffer Craig Hart and community members Brian Chiha and Ian McLean, the TEC-1G is a modernized version of the TEC-1 — boasting full compatibility with the original, hardware and software, and even its ability to run original monitor ROMs without modification.

Among the improvements made to the design of the TEC-1G include a default memory capacity of 32kB RAM and 16kB ROM to a maximum of 64kB RAM, RAM write protection capabilities, shadow memory and bank switching, and a faster Zilog Z80A-compatible CPU running at 4MHz with a "slow clock" mode for compatibility. There's support for a full QWERTY keyboard and optional joystick while the on-board hex keyboard has been upgraded with mechanical keyswitches, complete with LED backlighting, and an on-board 20×4 character LCD as the primary display.

Perhaps the biggest feature, though, is not in the hardware itself but in how it is being released to the world. "[The TEC-1G has] been produced with the blessing of Colin Mitchell, Talking Electronics owner," Jelic explains. "For the first time, the TEC-1G will also be fully free and open source, in both its hardware and software. The TEC-1G is the ultimate TEC-1!"

More information on the project is available on Jelic's Hackaday.io page; design files and source code for the TEC-1G are available on GitHub under the reciprocal GNU General Public License 3, along with a guide to assembling the device.