Відео

For accessing the data bus directly without using a flip-flop, you can access the input register directly. If you rewire the data bus to pin 42 - 49 you can read the bus value from reg PINL. Ex: ``` // Set as input DDRL = 0x00; // Read bus byte bus_val = PINL; ``` I really like idea!

i cant wait for the next version. long ago , i build one myself with the cypres chip , and 2 seperate eproms for the PID and the VID. I also made it with input protection diodes , the BAT83S . These have a low capacitanse. I also made some computer software in Delphi , but it was lost somehow.

This is great! I wonder if there is a fast micro that could do all that address decoding in software to reduce the chip count? I recently used a Ben Heck cool way of wiring to make a complex board - using thin wire wrap wire, on the board underside- you just solder through the insulation to the pins - so no wire stripping and you can do multipoint connections without cutting. Much more fun than measuring each wire. Quicker and neat too. Cool vid thanks.

Very nice little project. Perhaps another LED strip showing the number of lives?

Creative, terima kasih:)

I WANT one.

This looks great! For those of us with less focus on retro tech it would really help if there was a 1.8 V reference voltage built into the board as that's a super common voltage nowadays :)

I can't find the executable exe file on github...

Great video, need project!

My question is, since you can access the whole data and address bus, would it be possible to use an arduino to load programs into ram and execute using a special peek or poke command?

A little suggestion instead of the wire you used for this project I would suggest getting some 30 gauge Kynar wire wrapping wire. It is smaller, easy to solder, easier to manage and also comes in many different colors. I have been using that type of wire since the 80's for doing projects like this all the way back in elementary school. Hope you have fun

This is epic, I swear, before I got to the bit where you said what your idea was, I was going to post that you could output from the arduino to set some sort of mood lighting or environment lighting depending on the game being played. It made me think of that guy who decorated a Christmas tree with programmable lights and ran submitted code. You think that's a mess, you aint seen nothing! Happy New Year by the way mate (late I know)

the interface has 74LS244 , but the explanation digrams you're showing 74LS240 (inverted outputs) .. 😮

You could use one of those electric shock games and when you die you get a shock that would be funny 😂 well done on the project 👍

Hi, what a great idea 👍 Really enjoyed the way that you described the steps from the drawing to the working prototype. You made it very easy to understand what was happening within the actual hardware. How about Health in Dan Dare or one of the Dizzy games?

It’s fun to play with old hardware when the designs were so much simpler…. Ah

An idea I had, started but not seen through, was to do something similar for a speedometer and rpm cluster to read directly from the memory from older games. I wanted to send the data directly to the cluster as an initial PoC, but then creating a UDP telemetry server so other standard racing sim telemetry clients could consume the data. Inversely, I also wanted to inject inputs from an external controller into the game (in this case a steering wheel with analog throttle and brake) where only digital inputs were available.

I love this, very imaginative, though I have to say you are really hardcore doing this on vero, i’d have gone straight to ki cad and got them from china. You could add a little oled screen and some buttons to the arduino, to select from a number of games (that you know the address to monitor) then ad a jumbo led type thing for a life counter.

Cool.

I made 3 of these Z80 PIO breakout boards. One with Channel A as input and B as output, another with A and B as inputs and the third with A and B as outputs. I also put opto isolators on the I/O pins of the PIO for extra protection. (Hence the three versions) BTW, If you use the shorter edge conector, you can use these on the ZX81. LOL. The pinouts are in the same place.

I'm sad that dip ICs are slowly disappearing (because smd) and builds like yours will no longer be possible.

Great little circuit. You could have it flash a load of red LED's when you crash a car or get shot while flying a plane. You could try hooking up a rumble seat ?

I was thinking about the effective code in each led to process the incoming data from your arch up. I was expecting your code not to work as you were effectively forming & transmitting the end frame from your led frame - I assumed you’d then find out that the global didn’t go up to all ones) - but I was wrong. I’m now assuming that you don’t need the end frame at all. Never transmitting the end frame, and just the start frame must be sufficient to reset each led to await data. You might want to give that a try and see if it still works correctly

Lovely! What a great idea. How about hooking up IORQ and picking up port writes as well? Grab the lower three bits going to port 254 (or any even numbered port actually) and you've got the border colour; sync that to your LEDs for a nifty Philips "Ambilight" effect! Maybe? I wonder if the beeper (or tape loading) would drive it too fast, though? There's lots of interesting stuff in the system variables that might be fun to watch while BASIC is running. PPC (23621) is the line number being executed. Output that to an LCD?

Nice e-ink display showing the score on a Match Day or Jonah Barringtons Squash

That wire looks thick enough to start a car! - you need what I used to call “mod wire” which is far thinner, seems to be known as kynar wire.

Thanks for sharing your impressive work

I assume this is the approach the ZX HD interface takes. Sniff any writes to screen memory, then use that to rebuild the picture locally on the Raspberry Pi, and output the result using the HMDI port.

back in the day...u could link the speccy with a serial to an amstrad cpc developers would input on the spectrum and make minor ajustments to the software thats bulk dumped into the amstrads memory

Another interesting video. I think that Ben Eater has some videos about such cable management. Happy diode hacking!

That is silly. And I loves it!

The Z80 takes at least 3 clock cycles to write to the bus, although you wouldn't see the /WR and /MREQ until the second cycle, so assuming a 3.5Mhz Z80, and 16Mhz Arduino you'd have just under 10 clocks on the Arduino to capture the value on the data bus. This isn't enough time for a pin change interrupt handler due to the overhead (pushing registers to stack etc). However, a tight ASM loop *could* handle this, so long as the data was all on the same 8-bit port, and NOR gate input on another port, with all other pins unused. There are single cycle instructions to copy a port value to a register, so yeah, it's possible to remove the latch 😁

Very Interesting. :-)

Very nice! You could use an MCP23017 I2C expander chip. This will give you 16 bits of input or output which is controllable from the micro controller via the I2C pins (SCL and SDA pins). That means you only need two pins on the micro controller to control 16 pins on the MCP23017. That means you could run the project on a regular Arduino rather than an Arduino Mega. If you added a PCF8574, that will give you another 8 bits of IO on the I2C interface for the data bus. You would only then need one hardware IO to the micro controller: The trigger for when you get an address match. You could then read the latched data value via the PCF8574 and even run the project on an Arduino Nano 🙂

@Jim for the bottom layer you can use bare wires and then use insulated wires they way you can have less wires, and not tying the pull ups or enable signal is very common, great video .

That was a really fun little project. I enjoyed watching. I’m not sure that an Arduino would be fast enough to do everything in software, but a Pico definitely could, especially if you use the PIOs (although there’s quite a learning curve to using them). Also, when you were looking at the Z80 data sheet you mentioned that the read data wasn’t on the bus for very long. For a write the data sheet shows when the Z80 is outputting data. For a read it’s showing when the external device must be outputting the data so the Z80 can read it. The period when the data is actually on the bus will be dictated by the external device (ROM, RAM, etc) and will probably be more than long enough for the Arduino to sniff the value.

You should use the daisy chaining capability of the '688 like this: /MREQ to /G1, /P=Q1 to /G2, /P=Q2 to a NOR gate (74LS02) along with /WR. Not sure why you didn't use a 36 pin two row male connector on your board so the Arduino MEGA could be plugged in directly. Improved reliability!

how did you identify the address that manic minor is using for the air data ? gives me so many ideas.. the TK pie etc uses this sort of idea to sniff writes to the video data

If you wanted to extend this beyond a single address byte you could possibly remove the comparator part and instead latch the address and data every time there is a data write. The write could trigger an interrupt on the Arduino which could then process various actions based on the address. This would allow for full sniffing of the data bus, so for example you could reconstruct screen data.

Excellent and amazing!! Thanks for sharing

Excellent work! With enough knowledge of the game code itself the sky is the limit with this. The first thing I thought of was the ability to play sound samples. I've done a few arcade conversions that could be modded to trigger something like this.

Excellent, ❤

good work mate. Well done

Thanks for watching! Ideas I've had to get the ball rolling: - LED Strip Health Gauge - Split flap score counter/timer - Philips Hue integration? - External sound device for announcements - Small display showing game status? Map? Inventory? Would you be interested in this as a pre built device? A kit? I'll be manufacturing some soon

For that HDMI port - use a clothes pin or chip clip (something with low force) to hold it in place, position it, then solder the legs into place.

Try using your hot air to gently warm the pads up a tad then apply the solder paste. If it is still not going down very well, add a bit more heat.. You'll figure out the right amount of heat after a few tries. As long as you aren't heating the pad up enough to melt the solder you're fine.

Late comment: Try thinner (I use 2.8mm) branded flux-infused wick. I assure you will immediatly notice the difference. I tested and never returned to the wide cheap one. Also cutting small sections and using them with tweezers limits the heat disipation and is widely suggested, although I am too lazy for that.

Another great video jim

400 MHz sample rate is fast enough to watch what a Pentium II processor is doing. 🫣 Impressive stuff.

Is this analyzer compatible with PulseView?