Description

The Disk ][ ReAnalog Kit consists of two cards: the ReAnalog card and the Motor Control board. Together, these boards allow you to replace the old, possibly failing boards within your Disk ][ drive and make them just as good (or even better) as when they came off the assembly line! The new boards work great, regardless of whether you’re using your Disk ][ drive with your Apple II computer or with an Applesauce unit.

The Disk ][ ReAnalog and Motor Control boards are modern recreations of the original Apple Disk ][ analog and motor boards, designed to preserve the function of the originals while benefiting from improved PCB layout, modern components, and a cleaner physical design.

Disk ][ ReAnalog Card

The ReAnalog Card is a recreation of the original Apple Disk ][ Analog card from 1978, with the read path fully redesigned from scratch. The original MC3470 all-in-one read amplifier stage has been replaced with a completely new multi-stage analog and digital read chain, resulting in a cleaner and more stable read signal. Built on a 6-layer PCB, the board was designed with clean read paths, low-noise operation, improved grounding, better power handling, and reduced crosstalk in mind. Some inherent noise will always remain due to the brushed drive motor, but the overall signal quality is significantly improved over the original board. The -12V rail is no longer used on the card.

One of the most practical improvements is the large opening in the center of the board, which allows the magnetic head to be cleaned without removing the card from the drive. The board also features a keyed connector to help prevent incorrect cable insertion, along with added protection in case the cable is misconnected at the original Interface side. The ReAnalog Card includes a 3-position write protection jumper for normal operation, always writable mode, or always write-protected mode. A visible red LED indicates write activity, and pads are provided for users who want to add an external LED in parallel. The single potentiometer is factory-tuned for best Apple II read performance and should normally be left untouched, unless the card is being specifically retuned for archival imaging use.

• Complete redesign of the Disk ][ analog read path
• Large center opening allows head cleaning without removing the card
• Keyed connector helps prevent incorrect cable insertion
• Added protection against cable misconnection on the Interface side
• 6-layer PCB with improved grounding, power distribution, and signal routing
• Cleaner and more stable read signal than the original design• No -12V rail required on the card
• 3-position write protection jumper
• Visible write activity LED
• Optional external LED pads
• Single factory-tuned potentiometer for Apple II use

 

Disk ][ Motor Control Board

The Motor Control Board is a recreation of the original Apple Disk ][ Motor Control Board from 1978, using a cleaner modern PCB layout while preserving the original function and overall design approach. As with the earlier version, the original Sony CX065B motor controller IC is retained. The terminal block quick-disconnect is also retained, allowing easy connection without compromising reliability. The potentiometer is pre-tuned for a motor speed of 300 RPM, though minor adjustment may still be required depending on the motor.

• Recreation of the original Disk ][ Motor Control Board
• Retains the original Sony CX065B motor controller IC
• Cleaner modern PCB layout
• Quick-disconnect terminal block retained
• Pre-tuned for 300 RPM operation

 

Installation

The video below shows detailed installation instructions. You will need the following tools: A Philipps screwdriver, wire cutters, and either a small pair of wire strippers or a sharp hobby knife. Although the installation is straightforward, it still requires a minimum level of skill including cutting and stripping wires. You do not need to do any soldering or desoldering unless you specifically wish to avoid cutting the motor wires. If you have any doubts about your skills, please watch the video thoroughly before purchasing.

Note: The videos below show the first “purple” version of the ReAnalog card – the installation is identical with the current version.

Quick Install Video:

Full Install Videos:

Can I Buy the Boards Separately?

No. The ReAnalog and Motor Control boards were designed as a set. The boards are specifically tuned to each other. Only installing one of the boards on your Disk ][ drive would defeat the purpose of creating a modern, low power, noise-free environment. Even if only one of your boards needs replacing, we strongly recommend that you replace both boards for optimal performance.

Disclaimer

This kit involves modification of your original Disk ][ drive. The process is fully reversible, although restoring your Disk ][ to its original configuration will require a soldering iron. CT6502 and Karl ‘KKR75’ Asseily are not responsible for any damage to your Disk ][ drive, your floppy disks, or your Apple II computer or Applesauce unit from the installation or use of the ReAnalog Card and Motor Control Board.