Homemade z80 card with leds

[TheJetexproductions]

@pcuser80 I like it. Do you have the schematics for it?

[pcuser80]

@TheJetexproductions

No, i have done this on the fly, its real simple. only you need is datasheets.

[TheJetexproductions]

@pcuser80 Could you send them?

[pcuser80]

@TheJetexproductions

I dont have them any moore, Google is your friend.

Z80

74LS137 for the leds (latch)

74HC4020 divder for the clock (counter)

27128 eprom

clock module i used a 8Mhz

4093 Schmitt-trigger

some wire

and and lot looooooot of patience

[TheJetexproductions]

@pcuser80 I don't know much about this as im not from that era but does the latch connect to the address bus or the data bus

[pcuser80]

@TheJetexproductions

Data bus

[TheJetexproductions]

@pcuser80 Could you run by me what connects to what?

[extremisto47]

What compilatroa are you using for writing programm??? Is there some kind of AVR Studio for Zilog Z80??? Or it's only assembler???

[HLSDK]

Uou can get a z80 in dip or lots of other formats at mouser... but they are $5-10.

I'm considering this or another perhaps older cpu. Building a 256KByte card with some old motherboard ram for use with it.

I don't like that the z80 runs at only 6mhz, I'm used to 16-20 with the Atmel AVRs

[QuazarSamCoupe]

Z80 CPUs are available at maximum speeds of 4,6,8,10 and 20MHz.

Also worth experimenting with overclocking them - I've had a Z80 running stable at 28MHz.

[sundhaug92]

From what I know Zilog sells Z80 compatibles at up top a whopping 33MHZ.

[linuxrobotdude]

I think you can get the Z180s up to 40MHz TI uses them in their graphing calculators

[sundhaug92]

Meybe they are overclocking

[linuxrobotdude]

A saw a z80 clone designed in an FPGA running at 200 MHz.

[extremisto47]

@linuxrobotdude

200MHz ??????????

[linuxrobotdude]

@extremisto47 Yep. The point is that its not the design that makes older chips slow. Its the manufacturing process and the materials used. A Xilinx Virtex 5 FPGA can be flashed to emulate a 8088 at over a gigahertz. Its all in the transistor tech. For example IBM just designed a carbon based transistor that can be clocked at 150 GHz. No its not a typo.

[metasuperhyper]

You should make a computer with lots of switches and blinkenlights. And very little RAM. Yeah, lots of blinkenlights and 16 bytes of ram, thats what you should do. Or if you can't live with 16 bytes use 256 bytes.

[r06u3AP]

That sounds like and old IBM System/360 Mainframe!

[ZXRulezzz]

Sounds more like MITS Altair 8800 :-)

[MarkWillsUK]

Dear PCUser80,

This is great. I am getting ready to build some Z80 projects for the first time. Do you have a schematic for the clock circuit, or the whole circuit? I would love to build the same thing... Many thanks. Mark.

[Vyggy]

How much do I have to pay for a Z80 on ebay anyone know?

[Marks256]

a few bucks.

[256byteram]

Nice. Have you done any other boards? Good to see someone experimenting with old microprocessors.

[pcuser80]

Nope, only this board.

Maybe i start a new project with bright leds.

[FlyByPC]

It helps that the Z80 is available in DIP-40 form factor. (That, and it doesn't have all the memory-addressing weirdness of the x86 chips...)

[linuxrobotdude]

Yea, you don't need 3 latches and 2 buffers and a transceiver to use the Z80.