# TK2000 BUS EXTENDER

## DISCLAIMER

Any use of this project is **under your own responsibility**.
You will be responsible of checking the correct construction and functionality of your board.
By using this project You will agree that I cannot be held responsible if it will destroy any of your devices, damage your computer, burn down your house or whatever.

## Introduction

This board is a bus extender for the TK2000 computer, and allows plugging in up to 3 expansion boards into it.

Differently from what happens in the Apple II, the TK2000 does not differentiate between the expansion slots: every connector brings out the same signals, and it's up
to the boards installed in there to decode the signals appropriately and decide which memory/IO range to use.

![Empty adapter connected to a TK2000 clone](pics/adapter_empty.jpg)

![Adapter with two installed boards](pics/adapter_with_boards.jpg)


## Hardware

The board was designed with [KiCad](https://kicad.org/) EDA.

### Bill of Materials

| Component              | Qty | Type / Value                                            | Notes                                                                |
| ---------------------- | --- | ------------------------------------------------------- | -------------------------------------------------------------------- |
| P2, P3, P4             |  3  | 50 pin (2x25) female edge connector, 2.54mm pitch       | https://aliexpress.com/item/1005008354411366.html                    |
| P7                     |  1  | 50 pin (2x25) pin header                                | Optional, debug only                                                 |
| C1 - C6                |  6  | 10uF/25V+ 1206 MLCC capacitors                          |                                                                      |
| F1                     |  1  | 1.5A 1812 fuse                                          |                                                                      |
| F2, F4                 |  2  | 0.5A 1206 fuse                                          |                                                                      |
| F3                     |  1  | 0.25A 1206 fuse                                         |                                                                      |

Bridge JP1, JP2, JP3 and JP4 to connect the DMA and IRQ passthrough chains.

### Ordering the boards

You can order the board for this project at [PCBWay](https://www.pcbway.com/project/shareproject/TODO.html) and support me or download 
the gerbers and have them printed wherever you like!!!