Junior universal memory
About the Junior universal memory PCB
Junior universal memory is an open source PCB design by laurent-fr, published on GitHub under the CC-BY-NC-4.0 license. It is a 2-layer board measuring 160 × 100 mm, with 38 components from 28 distinct parts.
Other key parts include the 6522, 2114, 2716, NE565 and LM311. By type, the board carries 15 ICs, 9 connectors, 9 capacitors, 4 resistors and 1 switch.
From the project
A replica of the Junior Computer (a KIM-1 clone) published by Elektor in the 80's
This board is inspired by Elektor Universal Memory Card published in 1983 http://retro.hansotten.nl/uploads/junior/articlesuk/universalmemoryuk198303.pdf with a different address decoding.
- be careful about resistor networks orientation - if you cannot find the various 100K resistor networks you can instead use standard 100K resistors soldered vertically with a common lead on top
Main components on the Junior universal memory
Junior universal memory bill of materials (BOM)
38 components, 28 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 6522 74LS373 | DIL-20 | IC1 |
| 1 | 2114 74LS373 | DIL-20 | IC2 |
| 1 | 2114 74LS245 | DIL-20 | IC3 |
| 2 | 2716 74LS138 | DIL-16 | IC4, IC5 |
| 1 | NE565 74LS00 | DIL-14 | IC6 |
| 1 | LM311 74LS30 | DIL-14 | IC7 |
| 1 | LM311 5564 | DIL-28 | IC8 |
| 2 | 74LS241 5564 | DIL-28 | IC9, IC10 |
| 2 | 74LS243 5564 | DIL-28 | IC11, IC12 |
| 1 | 74LS27 5564 | DIL-28 | IC13 |
| 1 | 74LS01 5564 | DIL-28 | IC14 |
| 1 | 74LS30 5564 | DIL-28 | IC15 |
| 1 | CONN_01X03_SOCKET C64AC | DIN-41612-AC | J1 |
| 3 | CONN_01X03_SOCKET Conn_01x03_Pin | CONN-3 | J2, J3, J4 |
| 3 | Conn_01x03_Pin | CONN-3 | J5, J8, J9 |
| 1 | C64AC Conn_01x03_Pin | CONN-3 | J6 |
| 1 | C64AB Conn_01x03_Pin | CONN-3 | J7 |
| 1 | SW_DIP_x08 | SW-8 | SW1 |
| 1 | 220N 100n | CAP-4 | C1 |
| 2 | 100n | CAP-4 | C2, C4 |
Show 8 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 22N 100n | CAP-4 | C3 |
| 1 | 6N8 10µ | CAP-POL-3 | C5 |
| 2 | 6N8 100n | CAP-3 | C6, C7 |
| 1 | 100N 100n | CAP-3 | C8 |
| 1 | 47N 100n | CAP-3 | C9 |
| 2 | R_Network08 | RES-NET-8 | RN1, RN3 |
| 1 | R_Network09 | RES-NET-9 | RN2 |
| 1 | R_Network04 | RES-NET-4 | RN4 |
Junior universal memory design files
The KiCad project lives in the laurent-fr/junior_computer_replica repository on GitHub; these links point at the commit this page was built from.
Junior universal memory: common questions
How big is the Junior universal memory PCB?
The Junior universal memory measures 160 × 100 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Junior universal memory?
38 components, from 28 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 Junior universal memory design files?
From the laurent-fr/junior_computer_replica 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 Junior universal memory design in my own project?
It is published under CC-BY-NC-4.0, which limits how it may be reused; read the license before building on it.
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