PI/Arduino Processor Emulator

[andrewsm]

Well I finally started to build my Cheapo fluke emulator into a case today. Still working on it but so far it will do most essential stuff for a 8080 and a Z80. Thought I would share it on here. When I have got it all together I could prob make more up for a reasonable price if anybody wants a good debug tool but cant afford the flukes.

Hurray Banana2016-09-04 14:37:09

 

[Hurray Banana]

very interesting project

 

[silverfox0786]

wow that looks cool

 

[andrewsm]

Thanks. I know others are working on similar arduino based emulators on here but I started this without knowing and developed it to debug the space invader boards I had. Its since fixed frogger and is growing arms and legs. I picked a Raspberry Pi as I could use that as a front end for the Arduino code. Up to that point the arduino executed a list of commands via a terminal, but that was getting tedious so a Pi has provided a simple output. Stick a 3.5" display on it and some LEDS, and now it is a decent bit of kit. Still got the interface connectors to wire up and a few other things but getting there.

 

[andrewsm]

So far it can do the following:
1) Create a static address bus with any bit pattern for tracing stuck address lines etc.

2) Read data from an address

3) Write data to and address, works so far with 2114 RAM, others will follow

4) Read and write to I/O ports

5) Read a block of data from any address. Ideal for checking the ROMS are working

6) Performs a shift test on Space Invaders boards.

7) Writes a Block of data.

8) Copies a block of data

9) Can load a block of memory into a datafile. Im working on it to create a BIN file directly and either send it over WIFI or onto a memory stick.

10) For space Invaders it will clear the video RAM and write any characters or strings to it.

The above list is current and has helped me debug a few boards so far however its only the start as Im working on other things such as a audio probe and logic probe etc etc.

Processors will be switched by simply clicking a box to select them. I cant justify a fluke but this probably is the next best thing hopefully.

 

[PaulSwan]

Looks nice! I've not done much on the "front end" side of things on mine - it's not my area of expertise
I'm working on DEC T11 at the moment but after that I have a probe head with cut tracks ready to use with 8080.

 

[andrewsm]

Thanks Paul. I know you have been working on something similar. Im still learning as a I go along since not programmed for years so now getting into C and also Python. Its coming on well as Ive now wired the connectors up and bolted it all together. Its an ongoing project but getting used as well.

 

[grobda]

nice! want!

 

[andrewsm]

Still working on it. Today I fitted a probe so it now has a built in logic probe that can be switched to audio for probing sound as well.

Once Im happy its working well, I will prob offer them for sale at a figure yet to be decided. My aim is to make a unit which will be a standalone debug station for variety of boards. Other ideas I have is to make it read and write eproms etc etc.

 

[Hurray Banana]

I think I definitely would be up for one if these mate

 

[andrewsm]

where abouts in Glasgow are you Grobda? Maybe we could meet up and you can see it in action?

 

[andrewsm]

Hey Hurraybanana. Once Ive got it stable and doing what I want then definately mate. Its quite labour intensive to build but then this is the first one. I have been using it strewn around my desk for a while now but putting it in a box had made it look pretty decent I think. If I do make more up to order, then a full operating manual would be provided plus software updates as really the hardware all works its just down to software now.

 

[Hurray Banana]

cool

 

[Paul_in_nottingham]

Great project - love stuff like this.

 

[KmanSweden]

Once Im happy its working well, I will prob offer them for sale at a figure yet to be decided. My aim is to make a unit which will be a standalone debug station for variety of boards. Other ideas I have is to make it read and write eproms etc etc.

Best news I've read all day.

 

[DABYX]

That's a pretty neat looking piece of kit! Amazes me how clever some of you lads on here are.

I'm sure it'd come in useful for many people, nice job

 

[andrewsm]

Another update on this project.

I've now added a full function probe arrangement. When set to digital, it will display either Low or High for the logic levels. No problem I hear you say, except this will also show Floating pins, duty cycle and also a indication on what type of signal its seeing. So without using a scope, you can see whether its active low or high or more a clock pulse.

Couple of pics in action.

On the left is the signal probed using a scope. On the right is the same signal probed with my tester.

Reading the display from left to right is as follows: Duty Cycle in %, Type of signal. (Active High), L indicates its a Logic probe and the last o is the activity indicator. One the top line, the first 4 digits are the address and then data is displayed in the right two digits. At the moment no data is present and the address is set 0000.

If the probe is set to analogue, The display changes to display the measured voltage plus a selectable amplifier is engaged to probe for audio signals so tracing sound faults is possible too.

I have decided that I will be building these to order if anybody is interested. Price has yet to be set as need to work out materials and labour.

andrewsm2016-04-17 15:48:38

 

[andrewsm]

Bit more progress has been made on my Functional tester. Ive now added a full test screen allowing test sequences to be stored in files for different boards. Once stored, they can be loaded back in and run as single tests or as a full test sequence on another board of the same type. If a test fails, debug info is then provided. Additional commands can be added in to set addresses or data buses etc.

 

[Hurray Banana]

This is awesome mate, I feel feature creep coming into play, great when you see a multitude of possibilities. Top effort

 

[andrewsm]

Cheers mate. Ye growing arms and legs!