Z-80 Simple system v1.0

I used JLC PCB to make my first PCB version of my Wire wrap build.

PCB's arrive

IC Sockets soldered on to the board.

Assembled and ready for Testing

New board with test breakout board assembled

A simple system is taking shape, left is breakout board connected to Z-80 PIO for PS/2 Keyboard interface.

Schematic Page 1 of 2, System Clock, Reset, Address decoding.

Schematic Page 2 of 2, Z-80 CPU, Z-80 PIO, Z-80 CTC, 8K EPROM/RAM

Parts list:

IC 1 = Z80AIC 2 & 3 = 27C64 EPROM or 6264 SRAMIC 4 = Z80A CTCIC 7 = Z80A PIO IC 8 = 74HCT32NIC 9 = 74HCT04IC 10 = 74HCT139Q2 = 4Mhz Crystal Diodes Incorporated GB0400034R1,2 & 7 = 10K ohm resistor 1/4 wattR4 & 6 = 1 Meg ohm resistor 1/4 wattR8 = 4.7K ohm resistor 1/4 wattRN3 = 4.7K Resistor Network Bourns Inc 4606X-101-472LF RN4 = 4.7K Resistor Network Bourns Inc 4609X-101-472LFSV1 & 3 = 40 Dual row FEMALE Pin Header with long leads, Samtec Inc. SSQ-120-03-T-DSV2-7 = 3 Pin Male header T2 = 2N3904 NPN Transistor C1 = all 0.1 uf Capacitors KEMET C322C104K5R5TA7301C2 = 1.0 uf Capacitor C4 = 220 uf Capacitor Rubycon 5ZLH220MEFC8X11.5C3 & 10 = 22 pf Capacitor

z88dk base setup using their generic Z80 model

This file modifies the generic Z80 model's settings at compile time

File: simz80.inc

#pragma output CRT_ORG_CODE = 0#pragma output CRT_INCLUDE_PREAMBLE = 0#pragma output CRT_ORG_DATA = 0x2000 // Point to start of RAM for data#pragma output CRT_MODEL = 1#pragma output REGISTER_SP = 0x4000#pragma output CRT_STACK_SIZE = 256#pragma output CLIB_MALLOC_HEAP_SIZE = 0#pragma output CLIB_STDIO_HEAP_SIZE = 0
Example of my command line compiler settings, create a BIN file, use the simz80 modifications. See the z88dk for details on all the compiler options:
zcc +z80 -m -g -s --max-allocs-per-node2000 -SO3 -startup=1 -clib=sdcc_iy Hyundai_256x128.c z80_pio.c main.c -o z80_test_code -lm -create-app -pragma-include:simz80.inc --c-code-in-asm

Example program write and write to the Z80 PIO

#include "z80_io.h" // Z80 PIO define functions#include <z80.h>#include <stdlib.h>
int main(){
char c;// initialize PIO ports
z80_outp( Z80_PIO_A_CTL, Z80_PIO_M0); // set mode 0 byte outputz80_outp( Z80_PIO_B_CTL, Z80_PIO_M1); // set mode 1 byte input
z80_outp( Z80_PIO_A, 0x05); // write data to port A
c = z80_inp(Z80_PIO_B ); // read data from port B

return 0;};

File: z80_io.h

/* Z80_IO.h *//* Z80 IO DEF */

/* define logic mask */
#define Bit_mask0 0b00000001#define Bit_mask1 0b00000010#define Bit_mask2 0b00000100#define Bit_mask3 0b00001000#define Bit_mask4 0b00010000#define Bit_mask5 0b00100000#define Bit_mask6 0b01000000#define Bit_mask7 0b10000000

// User system Define Z80 PIO location#define Z80_PIO_A 0x00 // Port A#define Z80_PIO_B 0x01 // Port B#define Z80_PIO_A_CTL 0x02 // Port Control A#define Z80_PIO_B_CTL 0x03 // Port Control B
// Z80 PIO Mode define#define Z80_PIO_M0 0x0f // Mode 0 Port is output only#define Z80_PIO_M1 0x4f // Mode 1 Port is input only#define Z80_PIO_M2 0x8f // Mode 2 Port is Bidirectonal operation#define Z80_PIO_M3 0xCf // Mode 3 Port is port direction can be // set per bit via direction mask. // this command expects a mask byte to follow // 0 bit = output and 1 bit = input //
// Z80 PIO interruot setup
#define Z80_PIO_EI 0x87 // Enable PIO interrupts// The following bit wise OR with above
// Mode 3 interrupt options// Bit D5 Look for port to be High or low state.// where set to 0 for low, 1 for high// Bit D6 AND/OR state, AND all ports must be in// active state, or only one need be in active state // for interrupt. Bit D4 is mask byte to follow,// Bit set to 1 that port bit is ignored, 0 watch port bit.

#define Z80_PIO_EI_MF 0b00010000 // Mask follows command#define Z80_PIO_EI_AND 0b01000000 // AND Bits #define Z80_PIO_EI_OR 0b00000000 // OR Bits #define Z80_PIO_EI_HIGH 0b00100000 // HIGH Transistion triggers#define Z80_PIO_EI_LOW 0b00000000 // LOW Transistion triggers

#define Z80_PIO_DI 0x07 // Disable PIO interrupts
// Z80 PIO 0 address__sfr __at 0x00 Z80PIOA;__sfr __at 0x01 Z80PIOB;__sfr __at 0x02 Z80PIOA_REG;__sfr __at 0x03 Z80PIOB_REG;
extern void z80_io_write( unsigned char port, unsigned char data);extern unsigned char z80_io_read( unsigned char port);
void z80_pio_write_bit(unsigned char port, unsigned char bit, unsigned bit_state);unsigned char z80_pio_read_bit(unsigned char port, unsigned char bit);

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