# Minimalist ECB (MECB) - Grid 16V8 PLD Card
Plain Grid 16V8 PLD Card for the Minimalist Europe Card Bus (MECB). A Retro Computing Modular System Bus for 8-bit Retro Experimentation.
- **Seller:** [Digicool Things](https://www.lectronz.com/stores/digicoolthings), Auckland, New Zealand
- **Price:** $4.90 (USD, before shipping and taxes)
- **Availability:** In stock
- **Categories:** Retrocomputing, Kits, Platform
- **Product page:** https://www.lectronz.com/products/minimalist-ecb-mecb-grid-16v8-card
## Options
**Hardware Pack**
- No thanks
- Hardware Pack [Add $6.00] (5 left)
**Component Pack**
- No thanks
- Component Pack [Add $8.00] (5 left)
## Links
- [Documentation](https://digicoolthings.com/minimalist-europe-card-bus-mecb/)
## Images
## Description
**Note:** The Grid 16V8 PLD Card is supplied in Kitset form only (assembly required). The base price is for the double-sided silkscreened Grid 16V8 PLD Card PCB ONLY. The optional packs are required to make a complete Grid 16V8 PLD Card Kitset. If you already have the required components, then you can just order the PCB only.
You may also be interested in the similar **Grid 22V10 PLD Card**, and also the **Prototype** Card family (all listed seperately).
## 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) robust and reliable 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 16V8 PLD Card Design
### Grid 16V8 PLD 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.
- A MECB standardised 16V8 PLD glue-logic chip to provide 3 Chip Select outputs (CS0, CS1, CS2) with a 2KB MREQ and a 8 byte IORQ memory map granularity.
- All remaining board space (with exception of mounting hole clearance), utilised for through-hole pads, in a 0.1″ perf-board style plain Grid.
The Grid Card family 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.
This Grid 16V8 PLD Card enhances the related plain MECB Grid Card (see seperate listing), with the addition of the glue-logic 16V8 PLD chip to simplify prototyping new MECB I/O cards etc. There are also **Prototype** Card equivalents available with connected 3-hole strips (for ease of wiring 0.3" and 0.6" DIL packages). Please see the seperate Tindie product listings.
**Note:** Please also see the seperately listed **Grid 22V10 PLD Card** for an ATF22V10 version of this card.
## What You Get
To satisfy everyone's differing needs, I've split the Grid 16V8 PLD Card Kitset into Optional Add-on Packs.
Firstly, note that the base price is for the double-sided silkscreened Grid 16V8 PLD Card **PCB Only**.
Then you add the *optional* packs 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 and 1x 3 pin headers)
- 4x M3 Nylon PCB Spacer 12mm
- 8x M3 Nylon Bolt 6mm (for Spacer mounting)
*Optional* **Component Pack** includes:
- 1x 20 pin Zero Insertion Force (ZIF) IC Socket
- ATF16V8 PLD Chip Tested and Programmed as per the linked Video (i.e. CS0 = $E0-$E7, CS1 = $E8-$EF, CS2 = $F0-$F7 I/O Address ranges).
- 0.1µf Bypass Capacitor
**BONUS:** If you order ***both*** Optional Packs (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 16V8 PLD Card BOM
The following is a full Bill Of Materials (BOM) to allow fully assembling your Grid 16V8 PLD Card, ready for adding your own project designs.
Note that the PCB is supplied, and **all components are available via the two option packs**.
Some components are of course optional. For example, you may not want the 16V8 PLD to get started. Also, you may choose to just use a regular IC Socket. I do highly recommend an IC Socket is used as it is likely you will eventually want to re-program your 16V8 PLD.
### Default (PCB Only)
| Item | Qty |
| -------- |:--------:|
| MECB Grid 16V8 PLD Card PCB | 1 |
### Optional Packs
| Item | Qty | Source |
| -------- |:--------:| -------- |
| DIN41612 Male R/A 364 Connector | 1 | Hardware Pack |
| 40 pin PCB Header Strip | 2 | Hardware Pack |
| M2.5 Bolt 10mm Thread Length | 2 | Hardware Pack |
| M2.5 Nut | 2 | Hardware Pack |
| M3 Nylon PCB Spacer 12mm | 4 | Hardware Pack |
| M3 Nylon Bolt 6mm | 8 | Hardware Pack |
| DIP20 Zero Insertion Force (ZIF) IC Socket | 1 | Component Pack |
| ATF16V8 PLD DIP20 (U1) | 1 | Component Pack |
| 0.1µf Capacitor 5mm (C1) | 1 | Component 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 Grid 16V8 PLD 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 Prototype Cards (which preceded the current Grid Card family). A specific MECB Grid Card family introduction video will be released soon.
## Shipping policy
We pride ourselves with our "Next Business Day" Shipping Policy, and robust carton packaging. We also build to order, so if you order items with an "Assemble it for me" option selected, it may slightly delay shipping (while we build it for you).