Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Zilog Z80 Support for begginers

Not open for further replies.

Mario Blunk

Newbie level 6
Oct 30, 2009
Reaction score
Trophy points
Activity points
Zilog Z80 Support

Hello all !

If there are any questions on programming and hardware designing of Z80 components like CPU, SIO, PIO, CTC I give advise.

Personally I strongly recommend the Z80 for educational purposes. Please also have a look at my site

Cheers, Mario

Re: Zilog Z80 Support

Hi! Yes, I agree. Z80 and peripheral chips are excellent tools to learn basic computer theory hardware and software.

I designed the N8VEM SBC and peripherals for education because it is such a good tool. The parts are cheap and boards easy to make. They are very reliable too.

**broken link removed**

Thanks and have a nice day!

Andrew Lynch

Re: Zilog Z80 Support

Hi Andrew !

thanks for your comments. If you don't regard me as a competitor: What if we link our homepages to each other ? Means I set up a link to your site. You in turn set up a link to my site ?

Cheers, Mario

Hi! Thanks! I offer the N8VEM project for educational and/or entertainment purposes only. If others also do similar things, I think it is great and do not consider you or any one else "competition". The N8VEM home brew computing project is strictly non-commercial and competition implies some sort of business arrangement.

The N8VEM project is purely non-commercial amateur/volunteer project to help builders make their own home brew computer. All the information for hardware and software is freely available and publicly posted. The PCBs are available for convenience only but if you can make your own that would be great.

I wish you the best of luck with your project! You are welcome to the N8VEM home brew computing project if you would like to join. No purchases necessary.

Thanks and have a nice day!

Andrew Lynch

helooo ,
hey i recently start playing with a z80 ilog but i have a question for u because i can t find anywhare on the net . I want to make a guessing the number game for z80 assembler code but i need a code . i want to put z80 CTC in counter mode to let it number continuously until i pre3ss the go key after i press go the value from the counter should be stored in a register and after that i must enter numbers from 0 to 15 from the z80 keyboard and the value which i enter from z80 should be compared with the value stored in a register from the counter if the number are equals than it will show on the z80 7sgdisplay the guessed number if are not equal than it should ring a tone pls help me send me the code please if ukindly can on or post it here thank u very muchj

CTC programming

;Ok, so first you need to assign your CTC hardware addresses like:

CH0 equ 0h
CH1 equ 1h
CH2 equ 2h
CH3 equ 3h

;Now you need to initialize a timer channel e.g. Ch0:

;init CH0
;CH0 divides CPU CLK by (256*16)
ld A,00100111b ; interrupts off, timer mode on
; prescaler=256, external start mode off,
; start upon loading time constant,
;loading the time constant follows later
; channel reset, this is a control command

out (CH0),A ; load configuration into channel 0
ld A,00Fh ; time constant 15d defined
out (CH0),A ; and loaded into channel 0
; timer output pin T0 outputs pulses
; of frequency f= CPU_CLK/(256*16)

;the timer should be running continously now


;now every time you read from channel 0 you get a random value into A:

in A,(CH0)

;now compare A with any other register
ld B,077h ;B loaded with 77h
cp B ;compare A with B
;the zero flag is set when A=B

;do something depending on the zero flag like:

jp z,match

; or

jp nz,mismatch

;hope this helps solving your problem. cheers, Mario
Not open for further replies.

Part and Inventory Search

Welcome to