HardLabs

Z80-Calculator

BrandonMitchell1920·Z80-Calculator·KiCAD/Z80 Computer.kicad_pcb

Z80-Calculator PCB layout, top view — open source board by BrandonMitchell1920

About the Z80-Calculator PCB

Z80-Calculator is an open source PCB design by BrandonMitchell1920, published on GitHub. It is a 2-layer board measuring 199.4 × 125.7 mm, with 86 components from 32 distinct parts.

Other key parts include the NE555P, 74HCT245, Z80, 74HCT138 and 28C64. By type, the board carries 17 ICs, 17 capacitors, 16 modules, 14 resistors, 10 switches and 8 diodes.

It belongs with the retro computing and displays & leds designs in this gallery.

From the project

Simple Z80 calculator built as a learning exercise

This is a simple Z80 based calculator. I have been doing various electronics projects designed by other people and wanted to try making my own. I figured a calculator using the Z80 microprocessor would be a good choice as I had several of them on hand and could reference other projects if needed.

8K of RAM 8K of ROM 2 8-bit inputs (DIP switches) 6 push buttons Program select switch (software controlled) 4 seven segment displays (16-bit output) Expansion header for additional RAM or devices Blinkenlights! * 555 timer for variable clock rate (useful for debugging)

Main components on the Z80-Calculator

NE555P74HCT245Z8074HCT13828C647 Seg CK6264LED

Z80-Calculator bill of materials (BOM)

86 components, 32 distinct parts.

QtyPartRefs
1
NE555P
U1
7
74HCT245
U2, U4, U11, U14, U15, U16, U17
1
Z80
U3
2
74HCT138
U5, U9
1
28C64
U6
4
7 Seg CK
U7, U10, U12, U13
1
6264
U8
16
LED
A0, A1, A2, A3, A4, A5, A6, A7 +8
1
4MHz
Y1
1
5V Center Pos.
J1
1
2x20 Shrouded Header
J2
1
50K
50K Pot.
1
Program Select
SW1
1
Y + X
SW2
1
Y - X
SW3
1
Y * X
SW4
1
Y / X
SW5
1
gcd(Y, X)
SW6
1
sqrt(X)
SW7
1
Reset
SW8
Show 12 more
QtyPartRefs
2
SW_DIP_x08
SW9, SW10
8
LED
D0, D1, D2, D3, D4, D5, D6, D7
2
1uF
C1, C16
2
10uF
C2, C15
11
0.1uF
C3, C4, C5, C6, C7, C8, C11, C12 +3
2
104
C9, C10
3
2K
R1, R3, R4
1
1K
R2
1
22K
R5
4
10K
RN1, RN4, RN5, RN9
2
100 Isolated Network
RN2, RN3
3
2K
RN6, RN7, RN8

Z80-Calculator design files

The KiCad project lives in the BrandonMitchell1920/Z80-Calculator repository on GitHub; these links point at the commit this page was built from.

Z80-Calculator: common questions

How big is the Z80-Calculator PCB?

The Z80-Calculator measures 199.4 × 125.7 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Z80-Calculator?

86 components, from 32 distinct parts. The full bill of materials is listed on this page.

Where can I download the Z80-Calculator design files?

From the BrandonMitchell1920/Z80-Calculator repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Z80-Calculator design in my own project?

The repository has no license, so all rights stay with BrandonMitchell1920. Use it as a reference, and ask the author before reusing the design.

Similar boards