Z80 Home
My first Z80 system
Yes, this system is made by me Thomas Scherrer

Z80 system
My First Z80 system

1: 7493, clock divider
2: 7493, clock divider
3: 7493, clock divider
4: 7493, clock divider, the CPU runs a 1KHz, so I did not require any delay loops :-)

A1: 74138, CE RAM.
A2: 74138, CE both PIO'S.
A3: 74138, WR clock pulse to O1 and O2, with 7414 and 7432
74123: is a reset timer, used to give reset in a specified time after power-up or reset-button

O1: AM2952, Output Latch for the Display Address and control.
O1: AM2952, Output Latch for the Display Data Bus, 7bit.

RAM: 8 Kb, A special one made of 4 SMD 6116 (2 more at the bottom of the IC) and a decoder, nice eh?
EPROM: 2732, 4Kb I will rip the data from this soon..
Z80 CPU: A special military temperature range type
PIO: a pair of 8255' are used, one for the PARALLEL port, the other is for future use.
DISPLAY: LED ASCII DL2416 from HP, they look really cool.

The DIP-Switch are connected to the first PIO.

I'm sorry but I don't have the schematics for this system (yet), I did this back in 1990 at that time I started my education.

Some of my first assembler programs for this system, was written and assembled by hand !! here is my old original papers
All hex data was then programmed into an EPROM 2732 bit for bit in my own homemade EPROM programmer.
RAM TEST 1 A memory test program that works
RAM TEST 2 Display write routine for ram test "RAM IS 100% OK !"
RAM TEST 3 Display write routine for ram test "RAM FAIL *FEJL* "
RAM TEST 4 Display write routine for ram test "RAM-TEST RUNNING"

Another program called "Pulser" it uses both INT and NMI interrupts for inputs
PULSER 1 Main program 1
this program has also the display write routine like ram test placed at:
100H writing "CENTRONIKS PORT "
200H writing "EPROMER +128 ADR"
300H writing "STOP,PRESS RESET"