Z80 programming help

[Thedarkb]

Hello, I'm wondering if there's any way to modify the onboard ram on the z80 chip externally is it possible? and if so what pins do i use?

 

[Raven Luni]

Dam - I got all excited there expecting a good Z80 topic

 

[KrisBlueNZ]

Hello and welcome to the Electronics Point forums

AFAIK the Z80 doesn't have any on-board RAM - unless you consider the registers to be RAM! Perhaps you're talking about some Z80-based device that has on-board RAM? If so, tell us the name of it, and look in its data sheet. If it's less than 15 years old it may have some kind of debugging feature like JTAG or similar, which may support modifying RAM. If not, you're probably out of luck.

 

[Thedarkb]

Thanks, the chip has 256 bytes if internal ram like all z80s and i'll check the datasheet see if it is possible.

 

[p.erasmus]

This topic brings a qustion to my mind
How many people still use these Z80 types to me it seems they are out of the stone age ,Are they still useful for todays applications?

 

[Raven Luni]

Thanks, the chip has 256 bytes if internal ram like all z80s and i'll check the datasheet see if it is possible.

Z80s are single CPUs and do not have on-chip RAM or peripherals, You must be referring to a development board or something. A quick search turns up H-Z80 and Zboard as the top results - one of those perhaps?

This topic brings a qustion to my mind
How many people still use these Z80 types to me it seems they are out of the stone age ,Are they still useful for todays applications?

You kids are spoiled these days The Z80 will rock for all time! I have 10 of them which I plan to use soon

 

[p.erasmus]

You kids are spoiled these days The Z80 will rock for all time! I have 10 of them which I plan to use soon

Yea We might be spoiled however did not see much about them going around in the last few years.
I think the world has move on some how

 

[Raven Luni]

Yea We might be spoiled however did not see much about them going around in the last few years.
I think the world has move on some how

Theyre used internally in alot of common devices including hard drives

 

[p.erasmus]

Thanks for the info sure helps to realize that they are still used quite often

 

[Solidus]

Yep. They're also used in a lot of simple projects as the lack of standardized bussing protocols that exist in newer chips at the time meant that connecting peripheral chips such as RAM or UART converters (things like that) were a lot easier.

Z80 had an address bus and a data bus. Get out of my way, PCIe, 4MHz and 8bits should be good enough for anyone.

Hence why Z80/8080 projects use schematics, not block diagrams, and you don't have to wade through a multi-volume, 750-page datasheet to understand how to use them.

There's many documented SBCs using Z80s, although I'm rather ashamed of myself for never having the real want to build one.

 

[gorgon]

Some 25+ years ago I used several of the Zilog chips, and they are great. Z80 both NMOS and CMOS, Z8 microcontrollers in different variants, and the SUPER8 microcontroller. I simply loved the SUPER8, a great microcontroller, the best I've ever used, but with a sadly short lifetime.
Z80 is a great workhorse in many products and in several variants.