RC1 65K Expansion
tebl·RC-ONE·RC1 65K Expansion/RC1 65K Expansion.kicad_pcb
About the RC1 65K Expansion PCB
RC1 65K Expansion is an open source PCB design by tebl, published on GitHub under the CERN-OHL-1.2 license. It is a 2-layer board measuring 99.1 × 55.2 mm, with 23 components from 16 distinct parts.
Other key parts include the 74LS138, 74LS08, R6532 and 74LS00. By type, the board carries 6 ICs, 6 jumpers, 6 capacitors and 5 connectors.
It belongs with the retro computing and displays & leds designs in this gallery.
From the project
A recreation of the MOS KIM-1 microcomputer, the start of the Commodore-line of computers. Complete with hex keypad, six digit displays and a lot of 8-bit fun!
Among the years I've built quite a few computers, some bought as kits from various vendors and some I even designed myself based on available designs describes in books and other technical resources - above all, there was one I really wanted above all of them; the KIM-1! The RC-ONE is a functional replica designed in a modular fashion, for the specifics seaddresse specific module.

Main components on the RC1 65K Expansion
RC1 65K Expansion bill of materials (BOM)
23 components, 16 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | 74LS138 | DIP-16_W7.62mm_Socket | U1, U2 |
| 2 | 74LS08 | DIP-14_W7.62mm_Socket | U3, U5 |
| 1 | R6532 | DIP-40_W15.24mm_Socket | U4 |
| 1 | 74LS00 | DIP-14_W7.62mm_Socket | U6 |
| 1 | Expansion | Pin_Header_Angled_1x39_Pitch2.54mm | J1 |
| 1 | External IO | Pin_Header_Straight_2x10_Pitch2.54mm | J2 |
| 1 | Extra | Pin_Header_Straight_1x03_Pitch2.54mm | J3 |
| 1 | K1-K4 | Pin_Header_Straight_1x04_Pitch2.54mm | J4 |
| 1 | LOW RAM | Pin_Header_Straight_2x04_Pitch2.54mm | J5 |
| 1 | 8K1_RAM | Pin_Header_Straight_1x03_Pitch2.54mm | JP1 |
| 1 | 8K2_RAM | Pin_Header_Straight_1x03_Pitch2.54mm | JP2 |
| 1 | A4_INV | Pin_Header_Straight_1x03_Pitch2.54mm | JP3 |
| 1 | 8K3_RAM | Pin_Header_Straight_1x03_Pitch2.54mm | JP4 |
| 1 | IRQ_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP5 |
| 1 | 6532_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP6 |
| 6 | 100nF | C_Disc_D4.7mm_W2.5mm_P5.00mm | C1, C2, C3, C4, C5, C6 |
RC1 65K Expansion design files
The KiCad project lives in the tebl/RC-ONE repository on GitHub; these links point at the commit this page was built from.
RC1 65K Expansion: common questions
How big is the RC1 65K Expansion PCB?
The RC1 65K Expansion measures 99.1 × 55.2 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the RC1 65K Expansion?
23 components, from 16 distinct parts. The full bill of materials is listed on this page.
Where can I download the RC1 65K Expansion design files?
From the tebl/RC-ONE repository on GitHub, which has the KiCad layout; the links under Design files point to each one.
Can I use the RC1 65K Expansion design in my own project?
Yes, under the terms of its CERN-OHL-1.2 license, which tebl chose for the repository.
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