30 open source boards using the 74LS138
Real designs built with the 74LS138, from public GitHub projects: a quick way to see how others power, decouple and connect it. Each board comes with its KiCad files, full parts list and a render — and you can simulate its firmware on HardLabs.
Multi
homebrew8088
243.8 × 172.7 mm85 parts2LGPL-3.0238
Vic2020mainboard
danwerner21
357.8 × 124.5 mm127 parts2LNo license78
TI99 22
350 × 224.3 mm242 parts2LNo license50
TEC-1G
MarkJelic
63.5 × 85.6 mm31 parts2LGPL-3.046
TRS-80 Color Computer 3
qbancoffee
280 × 156.3 mm205 parts2LGPL-3.040
Dragon64
333.2 × 205.9 mm220 parts2LNo license34
Microdigital - TK 2000
clemarfolly
236.8 × 169.8 mm195 parts2LNo license17
Homebrewkeyboard
gfoot
162.6 × 99.1 mm85 parts1LUnlicense10
ESP32TI99 22
244 × 244 mm257 parts4LNo license4
AVR/ArduinoAPL1
acwright
150 × 100 mm44 parts2LCERN-OHL-P-2.01
V40 64K 640K ISA
145.8 × 91.4 mm23 parts2LGPL-3.0238
TRS-80 Color Computer 2 NTSC ( 26-3134B & 26-3136B)
230 × 170 mm150 parts2LGPL-3.040
Backup
333.2 × 205.9 mm218 parts2LNo license34
RC202-68000 SIO 1
MarkD833
101.6 × 53.3 mm40 parts4LCC-BY-NC-4.08
Lomax Thunder 186 Redux
RichCini
253.6 × 137.7 mm116 parts4LNo license1
Backup1
333.2 × 205.9 mm218 parts2LNo license34
Z80CTCDART2
lynchaj
100 × 100 mm73 parts2LNo license31
128 X 16 RAM V4 FINAL
ibm2030
180 × 95 mm108 parts4LNo license13
PPort
104 × 73.9 mm20 parts2LGPL-3.0238
BMS Master V5
TERA-TU-Graz
93.5 × 61 mm145 parts4LSHL-2.13
68000 LBE Board
101.6 × 53.3 mm34 parts4LCC-BY-NC-4.08
68000 SIO BOARD
101.6 × 53.3 mm33 parts4LCC-BY-NC-4.08
Z80VDC
100 × 100 mm63 parts2LNo license31
RC107-68000 ROM RAM 1
101.6 × 53.3 mm28 parts4LCC-BY-NC-4.08
68000 MPF BOARD
101.6 × 53.3 mm27 parts4LCC-BY-NC-4.08
64K 640K ISA
104 × 73.9 mm12 parts2LGPL-3.0238
RC203-68000 PIO 1
101.6 × 53.3 mm24 parts4LCC-BY-NC-4.08
68000 PIO BOARD
101.6 × 53.3 mm23 parts4LCC-BY-NC-4.08
512k
104 × 73.9 mm10 parts2LGPL-3.0238
RC208-68000 BOOTROM RAM 2
101.6 × 53.3 mm20 parts4LCC-BY-NC-4.08
The 74LS138 in open source designs
The gallery holds 30 open source boards using the 74LS138 from 15 GitHub repositories; a typical one measures about 124.9 × 97 mm and carries around 68 components.
60% are two-layer designs, the rest use four layers or more, and 33% carry an open source license.
The most starred is Multi by homebrew8088.
Parts used alongside the 74LS138
Microcontrollers on boards using the 74LS138
What boards using the 74LS138 are built for
74LS138: common questions
Where can I find a 74LS138 reference design?
Each of the 30 boards on this page is a real design using the 74LS138. Open one to see how it is wired up, with the full BOM, a render of the layout and links to its KiCad files.
What parts are used alongside the 74LS138?
The 74LS04, 74LS245, 74LS244, 74LS00 and 74LS32 appear in the most repositories here.
Which microcontrollers do boards using the 74LS138 use?
Most are built on AVR/Arduino (1) and ESP32 (1).
How big is a typical board using the 74LS138?
The median is 124.9 × 97 mm, and 60% are two-layer designs.
What is the most popular open source board using the 74LS138?
By GitHub stars, Multi by homebrew8088, with 238 stars.
Can I simulate one of these boards using the 74LS138 before building it?
Yes. HardLabs turns a board's netlist and BOM into a working simulation, so you can boot and test firmware against it with no hardware on your desk.