# Minimalist ECB (MECB) - TMS9918/TMS992x VDP Card
TMS9918/TMS992x VDP Card for the Minimalist Europe Card Bus (MECB). An 8-bit Retro Computing Modular System for 8-bit Retro Experimentation.
- **Seller:** [Digicool Things](https://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://lectronz.com/products/minimalist-ecb-mecb-tms9918992x-vdp-card
## Options
**Hardware Pack**
- No thanks
- Hardware Pack [Add $6.00] (5 left)
**Programmed ATF16V8 PLD Pack**
- No thanks
- Programmed ATF16V8 PLD Pack [Add $4.00] (5 left)
**Tested TMS9929A, TMS9918A, or TMS9928A + Crystal Pack**
- No thanks
- Tested TMS9929A + Crystal Pack [Add $15.00] (5 left)
- Tested TMS9918A + Crystal Pack [Add $15.00] (5 left)
- Tested TMS9928A + Crystal Pack [Add $15.00] (5 left)
## Links
- [Documentation](https://digicoolthings.com/minimalist-europe-card-bus-mecb/)
## Images
## Description
**Note:** The TMS9918/TMS992x VDP Card is supplied in Kitset form only (*assembly required*). The base price is for the double-sided silkscreened TMS9918/TMS992x VDP Card PCB ONLY. The optional packs provide some key components only. **Other components are also required to make a complete TMS9918/TMS992x VDP Card Kitset.** See BOM below (and photo).
### 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 board 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 a KiCAD Template, 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.
### TMS9918/TMS992x VDP Video Card
#### What You Get
To satisfy different people's needs, I've split the TMS9918/TMS992x VDP Card Kitset into optional add-on packs.
Firstly, note that the base price is for the double-sided silkscreened TMS9918/TMS992x VDP Card **PCB Only**.
Then, you can add the *optional* Packs that might be helpful to you. **Then, to complete the Kitset, you'll need to source the remaining parts to complete the BOM below.**
*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)
- 4x M3 Nylon PCB Spacer 12mm
- 8x M3 Nylon Bolt 6mm (for Spacer mounting)
*Optional* **Programmed ATF16V8 PLD Pack** includes:
- An ATF16V8 PLD Chip Tested and Programmed as per the linked Video ($80 I/O Address).
*Optional* **Tested TMS9929A, TMS9918A, or TMS9928A + Crystal Pack** includes:
*Either:*
- Verified Operational TMS9929A 50Hz Colour Difference VDP Chip
- 10.7386MHz Crystal
*OR:*
- Verified Operational TMS9918A 60Hz NTSC Composite Video VDP Chip
- 10.7386MHz Crystal
*OR:*
- Verified Operational TMS9928A 60Hz Color Difference VDP Chip
- 10.7386MHz Crystal
### TMS9918/TMS992x VDP Card BOM
The following is a full Bill Of Materials (BOM) to allow fully assembling your TMS9918/TMS992x VDP Card.
Note that the PCB is supplied, and some select components are available in the three option packs. **The rest of the components will need to be sourced by yourself.**
Some components are noted as being for the TMS9918 only, and a couple of resistors are for the TMS992x only. Also, some components are of course optional. For example the IC Sockets, although I do highly recommend IC Sockets are used.
I have also included an indication of where I sourced my parts from, if this is of assistance.
The Video linked below provides a full presentation of the initial TMS992xA VDP Card, as well as demonstrating the steps I took for assembly. Additional videos are available via the *Documentation* link, including a **presentation of the v2.0 update**, where TMS9918 support was added, and also a later **demonstration of the TMS9928A in use** (also, **comparing outputs of all 3 VDP chips**).
Via the *Documentation* link (below) you'll also find follow-up videos, and other videos presenting different components of the MECB retro 8-bit computing project.
| Item | Qty | Source | Part Number |
| -------- |:--------:| -------- | ---------------- |
| MECB TMS9918/TMS992x VDP Card PCB | 1 | JLCPCB | |
| DIN41612 Male R/A 364 Connector | 1 | AliExpress | 364-RA-M |
| M2.5 Bolt 10mm Thread Length | 2 | AliExpress | |
| M2.5 Nut | 2 | AliExpress | |
| M3 Nylon PCB Spacer 12mm | 4 | AliExpress | |
| M3 Nylon Bolt 6mm | 8 | AliExpress | |
| ATF16V8 PLD DIP20 (U1) | 1 | Mouser| |
| TMS9929A 50Hz (or TMS9928A/TMS9918A 60Hz) VDP DIP40 (U2) | 1 | eBay / AliExpress | |
| 10.7386Mhz Crystal HC49-U (Y1) | 1 | AliExpress | |
| 33pf Capacitor 5mm (C1, C2) | 2 | AliExpress | |
| 0.1µf Capacitor 5mm (C3,C4,C5,C6) | 4 | AliExpress | |
| 4 pin R/A PCB Header (for TMS992x only) | 1 | AliExpress | |
| 3.5mm Phone Connector Audio Jack PCB Mount | 1 | Mouser | SJ1-3523N |
| 9 pin Circular Mini-DIN Connector PCB Mount | 1 | Mouser | KMDGX-9S-BS-1 |
| 470R Axial Resistor 7.62mm (R2) | 1 | AliExpress | |
| 470R Axial Resistor 7.62mm (R1,R3) (for TMS9918 only) | 2 | AliExpress | |
| TMS-RGB Module (for TMS992x only) | 1 | https://tms-rgb.com/ | TMS-RGB |
| 75R Axial Resistor 7.62mm (R4,R5) (for TMS9918 only) | 2 | AliExpress | |
| 100nf Capacitor 5mm (C7) (for TMS9918 only) | 1 | AliExpress | |
| 47uf Capacitor 2.5mm (C8) (for TMS9918 only) | 1 | Mouser | ECE-A1CKA470l |
| B-01-A Ferrite Bead Axial (FB1) (for TMS9918 only) | 1 | Mouser | B-01-A |
| 2N3904 NPN BJT TO-92 (Q1) (for TMS9918 only) | 1 | Mouser | 2N3904 |
| 74HCT244 Tri-State Octal Buffer DIP20 (U3) | 1 | Mouser | SN74HCT244N |
| 4464 Dynamic RAM DIP18 (U4,U5) | 2 | eBay / AliExpress | |
| 74HCT04 Hex Inverter / Buffer DIP14 (U6) | 1 | Mouser | SN74HCT04N |
| DIP40 IC Socket | 1 | AliExpress | |
| DIP20 IC Socket | 2 | AliExpress | |
| DIP18 IC Socket | 2 | AliExpress | |
| DIP14 IC Socket | 1 | AliExpress | |
Your TMS9918/TMS992x VDP 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).
**Note:** Please visit the *Documentation* link (below) for more information on MECB, and for details of the various MECB Cards that have been design so far.
## 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).