TRS-80-Model-I-Expansion-Interface-Rev-D
About the TRS-80-Model-I-Expansion-Interface-Rev-D PCB
TRS-80-Model-I-Expansion-Interface-Rev-D is an open source PCB design by RetroStack, published on GitHub under the MIT license. It is a 2-layer board measuring 301.9 × 194.8 mm, with 185 components from 79 distinct parts.
By type, the board carries 79 capacitors, 35 resistors, 10 connectors, 3 transistors, 1 crystal and 1 relay.
From the project
Hardware Replica of the TRS-80 Model I Expansion Interface - Revision D
This project is a faithful reimplementation of the Expansion Interface (Revision D) of the iconic TRS-80 Model 1 computer system. My own revision, the E1, is designed to replicate the original board's functionality by using a PCB design 1-to-1 to the original, including components, interfaces, and even traces. The Expansion Interface extends the base Model 1 with additional dynamic RAM, a floppy disk controller, a parallel printer port, a second cassette interface, and a real-time clock. The entire project is available under the MIT license.
TRS-80-Model-I-Expansion-Interface-Rev-D bill of materials (BOM)
185 components, 79 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | MJE2955 | Q_Heatsink_Small_BCE | Q1, Q2 |
| 1 | 2N3904 | Q_Circle_EBC | Q3 |
| 1 | 4 MHz | Crystal | Y1 |
| 1 | Expansion Board Connector | Edge_Connector_40 | J1 |
| 1 | M1 Edge Connector | Edge_Connector_40_Reverse | J2 |
| 1 | Buffered Edge Connector | Edge_Connector_40_Reverse | J3 |
| 1 | Line Printer Connector | Edge_Connector_34 | J4 |
| 1 | Shugart Floppy Disk Bus | Edge_Connector_34 | J5 |
| 1 | Front View n(Cassette 1) | DIN5 | J6 |
| 1 | Front Viewn(Cassette 2) | DIN5 | J7 |
| 1 | Front Viewn(Cassette M1) | DIN5 | J8 |
| 1 | Front ViewnPower | DIN5 | J9 |
| 1 | Internal Expansion Connector | Internal_Expansion_Interface | J10 |
| 1 | 1N4148 | D | CR1 |
| 1 | MDA202 | D_Bridge | CR2 |
| 1 | 1N5231 | D | CR3 |
| 1 | 1N4735 | D | CR4 |
| 1 | ~ | Relay | K1 |
| 1 | ~ | Sw_Large | S1 |
| 16 | MK4116 | DIP16 | Z1, Z2, Z3, Z4, Z5, Z6, Z7, Z8 +8 |
Show 59 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | 74LS00 | DIP14 | Z17, Z28 |
| 1 | 75452 | DIP8 | Z18 |
| 1 | 4049B | DIP16 | Z19 |
| 2 | LM723C | DIP14 | Z20, Z21 |
| 1 | 74LS90 | DIP14 | Z22 |
| 2 | 4518 | DIP16 | Z23, Z24 |
| 2 | 74LS74 | DIP14 | Z25, Z26 |
| 1 | 74LS32 | DIP14 | Z27 |
| 2 | 74LS244 74LS244_Split | DIP20 | Z29, Z31 |
| 2 | 74LS243 | DIP14 | Z30, Z38 |
| 1 | 74LS04 | DIP14 | Z32 |
| 1 | 74LS123 | DIP16 | Z33 |
| 2 | 7416 | DIP14 | Z34, Z41 |
| 2 | 74LS157 | DIP16 | Z35, Z36 |
| 1 | DDU-4-7835 | DIP14 | Z37 |
| 1 | 74LS155 | DIP16 | Z39 |
| 1 | 74LS139 | DIP16 | Z40 |
| 1 | FD1771 | DIP40 | Z42 |
| 1 | 74LS30 | DIP14 | Z43 |
| 2 | 74LS244 | DIP20 | Z44, Z45 |
| 1 | 74LS20 | DIP14 | Z46 |
| 1 | 74LS175 | DIP16 | Z47 |
| 1 | 74LS273 | DIP20 | Z48 |
| 1 | 74LS367 | DIP16 | Z49 |
| 2 | 74LS240 74LS240_Split | DIP20 | Z50, Z51 |
| 27 | 0.1uF 50V | C_Disc_Small | C1, C3, C5, C7, C9, C11, C13, C15 +19 |
| 20 | 0.01uF 16V | C_Disc_Small | C2, C4, C6, C8, C10, C12, C14, C16 +12 |
| 1 | 10PF 10pF | C_Disc_Small | C43 |
| 1 | 75PF 75pF | C_Disc_Small | C44 |
| 4 | 47uF 16V | C_Pol_Radial_5D | C46, C47, C52, C56 |
| 1 | 47UF 47uF | C_Pol_Radial_5D | C48 |
| 2 | 1NF 1nF | C_Disc_Small | C50, C53 |
| 17 | 0.1uF 12V | C_Disc_Small | C54, C58, C59, C64, C65, C66, C67, C68 +9 |
| 1 | 2200uF 35V | C_Pol_Axial_41L | C55 |
| 1 | 10000uF 16V | C_Pol_Axial_63L | C57 |
| 1 | 220uF 16V | C_Pol_Radial_10D | C60 |
| 1 | 200PF 200pF | C_Disc_Small | C61 |
| 1 | 33UF 33uF | C_Pol_Radial_5D | C62 |
| 1 | 10uF 16V | C_Pol_Radial_5D | C63 |
| 1 | 10M | R_0.25W | R1 |
| 1 | 1k | R_0.25W | R2 |
| 2 | 2.2K 2.2k | R_0.25W | R3, R5 |
| 2 | 1.2K 1.2k | R_0.25W | R4, R15 |
| 1 | 2k | R_0.25W | R6 |
| 2 | 1k | R_Pot | R7, R8 |
| 2 | 3.3K 3.3k | R_0.25W | R9, R10 |
| 1 | 12K 12k | R_0.25W | R11 |
| 1 | 0.33 | R_2W | R12 |
| 1 | 68 | R_0.5W | R13 |
| 5 | 4.7K 4.7k | R_0.25W | R14, R16, R20, R24, R34 |
| 1 | 560 | R_0.25W | R17 |
| 1 | 4.7K 4.7k | R_Network5 | R18 |
| 3 | 33 | R_Network8 | R19, R26, R27 |
| 1 | 220 | R_0.5W | R21 |
| 4 | 150 | R_0.25W | R22, R31, R32, R33 |
| 1 | 20K 20k | R_0.25W | R23 |
| 1 | 200K 200k | R_0.25W | R25 |
| 3 | 10K 10k | R_0.25W | R28, R29, R30 |
| 1 | 5.6 | R_3W | R35 |
TRS-80-Model-I-Expansion-Interface-Rev-D design files
The KiCad project lives in the RetroStack/TRS-80-Model-I-Expansion-Interface-Rev-D repository on GitHub; these links point at the commit this page was built from.
TRS-80-Model-I-Expansion-Interface-Rev-D: common questions
How big is the TRS-80-Model-I-Expansion-Interface-Rev-D PCB?
The TRS-80-Model-I-Expansion-Interface-Rev-D measures 301.9 × 194.8 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the TRS-80-Model-I-Expansion-Interface-Rev-D?
185 components, from 79 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 TRS-80-Model-I-Expansion-Interface-Rev-D design files?
From the RetroStack/TRS-80-Model-I-Expansion-Interface-Rev-D 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 TRS-80-Model-I-Expansion-Interface-Rev-D design in my own project?
Yes, under the terms of its MIT license, which RetroStack chose for the repository.