Cpu
About the Cpu PCB
Cpu is an open source PCB design by eshazen, published on GitHub. It is a 2-layer board measuring 116.8 × 147.3 mm, with 46 components from 27 distinct parts.
Other key parts include the 74AS74, 74LS374, Z80CPU, AT28C256-15PU and 74LS244. By type, the board carries 16 capacitors, 11 ICs, 7 resistors, 5 diodes, 4 connectors and 1 crystal.
It belongs with the retro computing and displays & leds designs in this gallery.
From the project
Retro-tech HP-25 calculator clone using Z80
This is branch "ScopeClock". Building up another CPU board for used as a general purpose computer for the scope clock, along with the DAC/Interface board from that project, which (whew!) has an actual UART for the serial port.
Time for something new! The VFD HP-25 is cool and all, but I've lusted after an HP-97 most of my life, plus I love nixie tubes! Starting to think about a nixie-display HP-97 emulator. Probably no card reader, but a small printer is certainly doable. Inspiration from Oliver De Smet (archived elswhere in this repository just in case):
Main components on the Cpu
Cpu bill of materials (BOM)
46 components, 27 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | 74AS74 | DIP-14_W7.62mm_LongPads | U1, U17 |
| 1 | 74LS374 | DIP-20_W7.62mm_LongPads | U2 |
| 1 | Z80CPU | DIP-40_W15.24mm_LongPads | U3 |
| 1 | AT28C256-15PU | DIP-28_W15.24mm | U4 |
| 1 | 74LS244 | DIP-20_W7.62mm_LongPads | U5 |
| 1 | 74HC14 | DIP-14_W7.62mm_LongPads | U6 |
| 1 | 74LS139 | DIP-16_W7.62mm_LongPads | U7 |
| 1 | IDT71256SA | DIP-28_W15.24mm | U8 |
| 1 | 74LS32 | DIP-14_W7.62mm_LongPads | U13 |
| 1 | uA7805 | TO-220F-3_Vertical | U16 |
| 1 | 20.000MHz | DIP-14_W7.62mm_Socket_LongPads | X1 |
| 2 | hdr_2x8 | PinHeader_2x08_P2.54mm_Vertical | J1, J3 |
| 1 | Conn_01x06 | PinHeader_1x06_P2.54mm_Vertical | J2 |
| 1 | Conn_01x02 | Hirose_DF63-2P-3.96DSA_1x02_P3.96mm_Horizontal | J5 |
| 1 | jpr3 | PinHeader_1x03_P2.54mm_Vertical | JP1 |
| 1 | SW_Push | SW_PUSH_6mm | SW1 |
| 2 | LED | LED_D3.0mm | D1, D3 |
| 1 | 1N914 | D_DO-35_SOD27_P10.16mm_Horizontal | D2 |
| 2 | 1N914 | D_DO-35_SOD27_P7.62mm_Horizontal | D4, D5 |
| 1 | 10uF | C_Rect_L4.0mm_W2.5mm_P2.50mm | C1 |
Show 7 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 0.33uF | C_Rect_L4.0mm_W2.5mm_P2.50mm | C2 |
| 14 | 0.1uF | C_Rect_L4.0mm_W2.5mm_P2.50mm | C3, C4, C7, C8, C9, C10, C12, C13 +6 |
| 2 | 470 | R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal | R1, R5 |
| 2 | 4.7k | R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal | R2, R7 |
| 1 | 1k | R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal | R3 |
| 1 | 10k | R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal | R4 |
| 1 | RPACK_SIP_8 | R_Array_SIP9 | RN1 |
Cpu design files
The KiCad project lives in the eshazen/retro-25 repository on GitHub; these links point at the commit this page was built from.
Cpu: common questions
How big is the Cpu PCB?
The Cpu measures 116.8 × 147.3 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Cpu?
46 components, from 27 distinct parts. The full bill of materials is listed on this page.
Where can I download the Cpu design files?
From the eshazen/retro-25 repository on GitHub, which has the KiCad layout; the links under Design files point to each one.
Can I use the Cpu design in my own project?
The repository has no license, so all rights stay with eshazen. Use it as a reference, and ask the author before reusing the design.
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