TK2000 Disk Interface REDUX

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.

Sponsorship

This project is kindly sponsored by PCBWay. PCBWay specializes in manufacturing high-quality PCBs and makes them affordable to hobbyist and professionals alike.

The range of services they offer include PCB prototyping, assembly, instant quotes for your order, a verification process by a team of experts and an easy to use, hassle-free order process.

I'm grateful to PCBWay for the help in evolving and testing this project. You can order the currently released revisions of the board from them, see the link below!

Introduction

The TK2000 had a floppy disk adapter that came in form of a cart, connected directly to the computer, and supported only a single drive connected to it.

Luckily, the adapter was nothing more than a ripoff of the original Apple Disk II interface with some changes to adapt it to the TK2000 bus, so, starting with the recreation by btb as a base, I converted the original interface back to the TK2000, gaining support for a second floppy disk and configurable (via jumpers) I/O and ROM addresses.

Hardware

The board was designed with KiCad EDA.

Bill of Materials

Component	Qty	Type / Value	Notes
U1, U2	2	74LS138 DIP-14
U3, U8	2	27C32/64/128/256/512	Any of these EPROMS will work, as long as the access time is <=100ns
U4	1	74LS259 DIP-16
U5	1	74LS05 DIP-14
U6	1	NE555P or compatible DIP-8
U7	1	74LS132 DIP-14
U9	1	74LS323 DIP-20
U10	1	74L174 DIP-16
Q1	1	2N3096 TO-92
C1, C9	2	22uF/16V+ 2.5mm electrolytic capacitor
C2 - C8	7	100bF/25V+ 5.0mm ceramic caps

The ROMs

TODO

Configuring the address