TPDD Cable M4-tie
bkw777·TPDD_Cable·PCB/TPDD_Cable_M4-tie.kicad_pcb
About the TPDD Cable M4-tie PCB
TPDD Cable M4-tie is an open source PCB design by bkw777, published on GitHub under the CC-BY-SA-4.0 license. It is a 2-layer board measuring 10.4 × 16 mm, with 8 components from 6 distinct parts.
By type, the board carries 5 connectors and 3 transistors.
From the project
TTL-RS232 level-shifting cable for Tandy Portable Disk Drive
The BOM includes a grey cable. This black cable can be substituted if you want.
If you want to make 2 cables, one for Model 100 and one for PC/WP-2, then double the BOM components except for the cable, and cut the cable in half right in the middle. Otherwise just cut off the 9-pin plug to make one longer cable for Model 100 and other KC-85 clones.
Cut the unwanted plug off the cable. If building a Model 100 cable, cut off the 9-pin plug. If building a PC/WP-2 cable, cut off the 25-pin plug. If building both cables, cut the cable in half in the middle.

TPDD Cable M4-tie bill of materials (BOM)
8 components, 6 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 3 | DTA114EKA | SC-59 | Q1, Q2, Q3 |
| 1 | M20-7830442 TPDD_RS-232C | 2x4x2.54mm_edge_mount | J1 |
| 1 | RX | SMD_1.2x3 | P3 |
| 1 | RTS | SMD_1.2x3 | P4 |
| 1 | CTS | SMD_1.2x3 | P5 |
| 1 | DSR | SMD_1.2x3 | P6 |
TPDD Cable M4-tie design files
The KiCad project lives in the bkw777/TPDD_Cable repository on GitHub; these links point at the commit this page was built from.
TPDD Cable M4-tie: common questions
How big is the TPDD Cable M4-tie PCB?
The TPDD Cable M4-tie measures 10.4 × 16 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the TPDD Cable M4-tie?
8 components, from 6 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the TPDD Cable M4-tie design files?
From the bkw777/TPDD_Cable repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.
Can I use the TPDD Cable M4-tie design in my own project?
Yes, under the terms of its CC-BY-SA-4.0 license, which bkw777 chose for the repository.