Note: The Grid Card is supplied in Kitset form only (assembly required). The base price is for the double-sided silkscreened Grid Card PCB ONLY. The optional Hardware pack is required to make a complete Grid Card Kitset. So if you already have the required parts, then you can just order the PCB only.

Additional Note: If you prefer a prototype card with connected 3-hole strips (for ease of wiring 0.3" and 0.6" DIL packages), then please refer to my seperate Minimalist ECB (MECB) - Prototype Card listing.

What is Minimalist Europe Card Bus

Europe Card Bus (ECB) is a Retro CPU Bus standard from the late 1970’s / early 1980’s.

The “Minimalist Europe Card Bus” (as I’ve called it), is a Retro 8-bit CPU Bus and PCB design standard that I decided to define & document. The purpose of which is to provide a modular platform for me to re-experience the fun of experimenting with the different 8-bit CPU’s, and the various video and peripheral devices, that I grew up with in the late 1970’s and early 1980’s.

My goal is that of a robust and modular design platform which allows me to create interchangeable PCB cards, based on time proven reliable bus connectors and modern low-cost prototype PCB manufacturing.

i.e. A robust, flexible, and low cost way for me to re-create some of the early microprocessor circuits, that I’d originally built using Wire-Wrap methods back in the day.

As evident from the name, the Bus itself is based on a Minimalist implementation of the original Europe Card Bus (ECB) standard.

Standardised Mechanical Specification for a Minimalist ECB “MECB” Board

MECB Standardised Board Design Parameters:

• Satisfy the 100mm square maximum board size, for low-cost prototype PCB manufacturing.
• Utilise the lower cost 64-pin (Row A&C) DIN 41612 type C connectors, for cost saving.
• Ensure the DIN 41612 connector(s) can be easily centred across the board width, grid aligned.
• Provide two standardised corner holes, on the edge opposing the right-angle DIN connector, to allow for attachment of card handles (to ease board insertion & extraction), or for board mounting – refer next point.
• Provide an additional two standardised corner mounting holes on the edge with the right-angle DIN connector, to provide a full set of four corner holes (to allow for stand-alone board mounting).
• Standardise PCB corner rounding, for sharp corner removal consistency across all boards & visual tidiness.

MECB Standardised Board Design Notes:

• PCB layout is designed utilising 0.127mm (5.0 mils) grid setting.
• Board size is 99.822mm, which represents the greatest even multiple of 0.127mm (i.e. multiple of 0.254mm – 10.0 mils), that will fit within the desired maximum 100mm board dimension.
• Standard M3 sized mounting holes were chosen. An additional two mid-edge located mounting holes are specified for the Backplane boards only (to provide additional mechanical support).
• For reference, DIN 41612 connectors can utilise standard M2.5 mounting bolts (8mm length for the straight connectors, 10mm length for right angle connectors).
• Implemented as KiCAD Templates, to assist with simplifying the creation of each new MECB board design.

Please refer to the attached photo outlining all dimensions for the MECB Standardised Board Mechanical Specifications.

Grid Card Design

Grid Card Design Parameters:

• All dimensions and corner mounting holes, as per the MECB Standardised Board Mechanical Specification.
• A 64-pin header, clearly labelled with the A & C rows and pins 1 – 32, for ease of access to all bus signals.
• Power bus bars along the two sides of the card, to distribute the +5V and Ground power connections.
• All of the remaining board space (with exception of mounting hole clearance), to be utilised for free use through-hole pads, in a 0.1″ perf-board style plain Grid.

The Grid Card was inspired by my re-visiting my original 1980's Wire-Wrap process, where a plain grid is preferable for dense positioning of wire-wrap IC sockets and socket strips. Also, for those who prefer a plain grid for point-to-point wiring.

Note that there are also Grid Cards available with an on-board glue-logic PLD (either 16V8 or 22V10). There are also Prototype Card equivalents available which instead have connected 3-hole strips (for ease of wiring 0.3" and 0.6" DIL packages). Please see the seperate Tindie product listings.

What You Get

To satisfy everyone's differing needs, I've split the Grid Card Kitset into an optional add-on pack.

Firstly, note that the base price is for the double-sided silkscreened Grid Card PCB Only.

Then you add the optional Hardware Pack to complete the Kitset, depending on your parts requirements.

Optional Hardware Pack includes:

• 1x Right Angle Male DIN41612 364 Keyed Bus Connector
• 2x M2.5 Stainless Steel Bolt 10mm (2 required for Right Angle Connector)
• 2x M2.5 Stainless Steel Hexagonal Nut (for above Bolts)
• 2x 40 pin PCB Headers (to be cut into 2x 32 pin headers)
• 4x M3 Nylon PCB Spacer 12mm
• 8x M3 Nylon Bolt 6mm (for Spacer mounting)

BONUS: If you order the Optional Hardware Pack (to make a Complete Kitset), I'll include a laminated full colour MECB pin-out guide (as per photos). This can be then be glued to the side of your DIN41612 connector, for a very handy adjacent reference to the 64 pin header for bus signal access!

Grid Card BOM

The following is a full Bill Of Materials (BOM) to allow fully assembling your Grid Card, ready for adding your own project designs.

Note that the PCB is supplied, and all components are available via the optional Hardware Pack.

Default (PCB Only)

Optional Pack

Via the Documentation link (below) you'll also find related videos, and other videos presenting different components of the MECB retro 8-bit computing project.

Your MECB Grid Card Kitset order is shipped in a robust cardboard carton with packing, for safe delivery via New Zealand International Air Parcel (see example shipping photo).

PLEASE NOTE: The video linked below features the original V1.0 Prototype Card (which preceded the current Grid Card). A specific MECB Grid Card family introduction video will be released soon.