• FPGA-based Gigatron TTL kit
  • FPGA-based Gigatron TTL kit
  • FPGA-based Gigatron TTL kit
  • FPGA-based Gigatron TTL kit
  • FPGA-based Gigatron TTL kit
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innoelement

FPGA-based Gigatron TTL kit

FPGA-based Gigatron TTL kit

$22.00 USD
$22.00 USD
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Shipping calculated at checkout.

What is it?

System Alpha is a direct replacement combo CPU/Driver PCB for Williams System 3-7 pinball machines (1977-1984). It removes common failure points and improves long-term reliability.

What's in the box?

1x System Alpha main PCB. Optional: System 7 Add-on PCB kit for selected System 7 games.

Installation

Plug-and-play replacement: no rewiring or soldering required for standard install. Load ROM files by USB, then install and run setup from coin door service switches.

Warranty

1-year non-transferable warranty covering manufacturing defects. If compatibility or setup issues occur, contact support before return.

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Technical details

Description, documents, and source code.

This kit delivers a refined FPGA implementation of the Gigatron TTL microcomputer, originally built from discrete 7400-series TTL chips and ported to the Tang Nano 9K FPGA board

gigatron.io

hackaday…

This kit delivers a refined FPGA implementation of the Gigatron TTL microcomputer, originally built from discrete 7400-series TTL chips and ported to the Tang Nano 9K FPGA board

gigatron.io

hackaday.io

. It includes a custom adapter board that handles video and audio D/A conversion using discrete resistors and capacitors for an authentic retro experience

hackaday.io

. The VGA output now leverages an improved level-shifting scheme to eliminate the unstable signals observed with the original auto level converter

hackaday.io

. The XC9572XL CPLD originally used for voltage-level translation has been replaced with readily available components following its discontinuation. All resistor and capacitor networks have been reorganized into a cohesive SMD-only assembly for simplified soldering and lower cost. The result is a complete, low-cost, drop-in kit that preserves every Gigatron feature while providing a smoother build and stable performance for lightweight FPGA learning.

What is it?

A ready-to-solder FPGA-based replica of the Gigatron TTL microcomputer.

Includes FPGA bitstream for the Tang Nano 9K board, adapter PCB, all discrete components, and connectors.

Compatible with standard VGA monitors (160×120 @ ~60 Hz) and NES-style game controllers

Why did you make it?

To overcome the original design’s VGA instability caused by its auto-conversion logic, avoid sourcing the discontinued XC9572XL CPLD, and simplify assembly by moving to an all-SMD RC network.

What makes it special?

Stable VGA output with robust level shifting

Uses easily sourced, modern components in place of discontinued CPLDs

Clean, all-SMD passive network for quick assembly and low cost

Fully retains the vintage Gigatron instruction set, video, and audio capabilities

Videos

Original product page: https://www.tindie.com/products/johnson/fpga-based-gigatron-ttl-kit/

Documentation