HardLabs

Tandy1400

arlaneenalra·Tandy1400·1400-PSU/1400-PSU.kicad_pcb

Tandy1400 PCB layout, top view — open source AVR/Arduino board by arlaneenalra

About the Tandy1400 PCB

Tandy1400 is an open source AVR/Arduino PCB design by arlaneenalra, published on GitHub under the CC-BY-SA-4.0 license. It is a 2-layer board measuring 173.4 × 62.1 mm, with 39 components from 35 distinct parts.

Its main chip is the ARDUINO_NANO_V3.X, from the AVR/Arduino family. Other key parts include the MC34063, MEZD41502A-C, MEZD72401A-G, LM340T-12 and N7812-1PH. By type, the board carries 10 capacitors, 9 resistors, 6 ICs, 5 diodes, 3 connectors and 1 module.

It belongs with the power & battery designs in this gallery.

From the project

A small collection of KiCad boards for old/ancient Tandy 1400 Laptop Computers

A very rough potential replacement for a Tandy 1400 PSU. At this point the board has not been tested in any way, shape, or form and is only published for potential review.

2024-12-15 - Bug Fixes Upped C2 to 100uF, 47 seems to not quite be enough for the LCD to work well, you get some fading and potentially contrast issues. Ordered potentially replacement for the 15v DC-DC converter, if it works, I'll add the converter module to the repo and start an SMD version of the board.

Tandy1400, from the project README
From the project README

Main components on the Tandy1400

MC34063MEZD41502A-CMEZD72401A-GLM340T-12N7812-1PHTP5100 ModuleARDUINO_NANO_V3.X

Tandy1400 bill of materials (BOM)

39 components, 35 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
MC34063
U1
1
MEZD41502A-C
U2
1
MEZD72401A-G
U3
1
LM340T-12
U4
1
N7812-1PH
U5
1
TP5100 Module
U6
1
ARDUINO_NANO_V3.X
Arduino_Nano_v3.x
A1
1
IRF9540N
Q1
1
Battery
J1
1
Jack-DC
J2
1
MAINBOARD_OUT
J3
1
3A
F1
1
4.7K
4.7k
RV1
1
SW_DPST
SW1
1
31DQ06
D1
1
31D106
D2
2
1N5819
D3, D5
1
31DQ06
D4
1
330UH
330uH
L1
1
100uF 50V
C1
Show 15 more
QtyPartRefs
1
100uF 50V
C2
1
220PF
220pF
C3
1
0.1UF
0.1uF
C4
1
22uF 25V
C5
1
10UF
10uF
C6
1
2.2uF 50V
C7
1
0.22UF
0.22uF
C8
1
10uF 50V
C9
1
330uF 25V
C10
2
1k
R1, R6
1
10K
10k
R2
1
1
R3
1
15K
15k
R4
2
200K
200k
R5, R8
2
150K
150k
R7, R9

Tandy1400 design files

The KiCad project lives in the arlaneenalra/Tandy1400 repository on GitHub; these links point at the commit this page was built from.

Tandy1400: common questions

What microcontroller does the Tandy1400 use?

The Tandy1400 is built around the ARDUINO_NANO_V3.X, from the AVR/Arduino family.

How big is the Tandy1400 PCB?

The Tandy1400 measures 173.4 × 62.1 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Tandy1400?

39 components, from 35 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 Tandy1400 design files?

From the arlaneenalra/Tandy1400 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 Tandy1400 design in my own project?

Yes, under the terms of its CC-BY-SA-4.0 license, which arlaneenalra chose for the repository.

Can I test firmware for the Tandy1400 without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug AVR/Arduino firmware against it before you order a PCB.

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