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Falken
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As I read people buying 300W power supplies for this project I wondered: How many Watts or Amps does an X16 actually need? I could not find it in the specs but maybe I looked at the wrong place. Does someone have an answer?

 

Thank you.

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On 4/1/2022 at 6:46 PM, Falken said:

As I read people buying 300W power supplies for this project I wondered: How many Watts or Amps does an X16 actually need? I could not find it in the specs but maybe I looked at the wrong place. Does someone have an answer?

 

Thank you.

1.21 gigawatts with the flux capacitor upgrade. Not sure about a stock board though.

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On 4/1/2022 at 5:46 PM, Falken said:

As I read people buying 300W power supplies for this project I wondered: How many Watts or Amps does an X16 actually need? I could not find it in the specs but maybe I looked at the wrong place. Does someone have an answer?

 

Thank you.

The Commodore 64 uses around 1-2 amps on the 5V rail, depending on the generation and attached peripherals. I expect the CX16 to be similar.

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On 4/2/2022 at 5:19 AM, TomXP411 said:

The Commodore 64 uses around 1-2 amps on the 5V rail, depending on the generation and attached peripherals. I expect the CX16 to be similar.

Would that mean you could power the X16 with a USB power supply? They are easily obtainable in the 2 Amp range. Might also make the whole system cheaper.

Just a thought.

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On 4/8/2022 at 7:47 PM, Falken said:

Would that mean you could power the X16 with a USB power supply? They are easily obtainable in the 2 Amp range. Might also make the whole system cheaper.

Just a thought.

For the self-contained one, sure. The one with expansion slots will need more.

Assuming there will be a version with expansion slots. Poll or no poll, we're still at the mercy of the supply chain, and in the end it's David's decision what to build.

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At the command prompt with a flashing cursor (not performing any stressful workloads), my bread-boarded computer w/ similar hardware (VERA, 65C02, 2x VIA, 2x SRAM, 1x NAND flash, 8MHz clock, all discrete 7400-series address decoding logic, PS/2 keyboard) pulls 0.072A at 5V, or 350mW @2MHz while sitting at the READY prompt. If the real CX16 pulled twice that, it would still be under 1 watt.

Edit: I just cranked the clock up to 8MHz and the current measured was 0.114A, so ~0.570mA. If the real CX16 pulled twice that it would be OVER ONE WATT!!! All signs point to very lower power consumption.

image.thumb.png.96cc4fc330e0051b3df557d08765668a.png

Edited by Wavicle
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On 4/10/2022 at 12:14 AM, Jeff Pare said:

Isn't part of the reason for an ATX power supply having +/-12V for serial communication? I also think these voltages were available on the expansion slots.

Yes, it does simplify making a UART as a true RS-232C interface, with the longer cable runs that supports ...

... but I think the other part was because micro-ATX and mini-ITX cases will likely come with an ATX PS.

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On 4/9/2022 at 9:14 PM, Jeff Pare said:

Isn't part of the reason for an ATX power supply having +/-12V for serial communication? I also think these voltages were available on the expansion slots.

A MAX 232 chip uses a charge pump to generate levels that work for RS-232 transmutation with only a 5 V chip power supply. See https://en.wikipedia.org/wiki/MAX232 and then onward to the data sheets.

In industrial applications, having a maximum swing of voltage for signalling is great, as these environments usually have high noise and long cable runs. In an hobby/office environment signalling voltages can be a lot less and still work well.  

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On 4/10/2022 at 1:08 PM, Edmond D said:

1] A MAX 232 chip uses a charge pump to generate levels that work for RS-232 transmutation with only a 5 V chip power supply. See https://en.wikipedia.org/wiki/MAX232 and then onward to the data sheets.

[2] In industrial applications, having a maximum swing of voltage for signalling is great, as these environments usually have high noise and long cable runs. In an hobby/office environment signalling voltages can be a lot less and still work well.  

[1] Why I said "simplify" instead of "allow".

[2] Yes, if there is a serial connection to a computer where the hobby bench is in the basement and the computer is in the office upstairs, it might matter ... otherwise TTL is probably good enough. But, OTOH, for some people it might matter because a "proper" RS-232C connection is what they HAD, "back in the day".

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On 4/10/2022 at 2:26 PM, BruceMcF said:

a "proper" RS-232C connection

I've dealt with a whole bunch of improper "proper" RS 232 devices in my life. I use to have a book that was more or less a lookup/cross reference of a ton of devices to what their actual pin-out were so that a person didn't have to sit down a work one's way through. RS-232 was perhaps the worst standard in that no one checked/enforced compliance, unlike today where standards like USB make life vastly easier. Of course standards are changed/improved over time and fragment till the next one comes along to replace it. 

I was once part of a company that was manufacturing a DTE device. The put one full serial port on it implemented in hardware, and a second one with only Tx, Rx and Gnd wired up. When a customer asked for a  second full serial port, management came to the team and asked if it could be done by implementing it in firmware without redesigning the device/circuit board. 😞 

Anyway, for the hobbit who is running RS-232 over longer distances they would/should be aware that RS-232 isn't the ideal standard and choose devices/interfaces that were designed for the distance and the environment they are deploying in. 

PS - yes, you choose your words carefully, but others are sometime vague or unaware.

 

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On 4/10/2022 at 4:00 PM, Edmond D said:

Anyway, for the hobbit who is running RS-232 over longer distances they would/should be aware that RS-232 isn't the ideal standard and choose devices/interfaces that were designed for the distance and the environment they are deploying in. 

Hey now. I hope you mean hobbyist

Sometimes, that's all you have available. Of course, converting to RS-422 (or even to Telnet, via terminal adapter) for longer runs can be helpful, but that's not always practical when using hardware devices that don't involve computers. 

 

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On 4/11/2022 at 1:08 PM, TomXP411 said:
On 4/10/2022 at 6:00 PM, Edmond D said:

Anyway, for the hobbit

Hey now. I hope you mean hobbyist

🤣

Oh, and regarding communications links, there's always RS-485...

Whatever's better than current loop. 😉 

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On 4/11/2022 at 11:08 AM, TomXP411 said:

Hey now. I hope you mean hobbyist

I was out trolling for some humour. 😛 I suspect now I'll be watched by some evil eye. 

Anyway, for those here for the long run, they'll know that any physical communication media has its limitations and will adapt. 

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On 4/11/2022 at 2:08 PM, TomXP411 said:

Hey now. I hope you mean hobbyist.  ...

While I freely admit my feet are a little hairy, they are not that hairy.

And, yes, when what you want to use lets you choose from a bespoke 8bit parallel interface, SPI, and a UART, getting an adapter to take the UART to +/-12v is often the most direct workable connection for longer runs. I love SPI, but I don't want to run it from a first floor room to a basement bench (even American/Chinese first floor, never mind European first floor).

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On 4/11/2022 at 12:11 PM, kelli217 said:

🤣

Oh, and regarding communications links, there's always RS-485...

Whatever's better than current loop. 😉 

I have been using RS-485 with my PTZ cameras, and that's pretty handy for longer runs. I've even been considering connecting a PTZ joystick to my PC as a macro keypad (yes, I'm weird) using a RS-485/RS-488 USB UART. 

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If 12 Volt is important  You can always have a barrel connector taking current from a 12 v transformer with a small voltage regulator for the 5V lines.

Edited by Fabio
not clear first post
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PC power supplies have minimum load requirements to regulate correctly. The original IBM PC power supply (192W) had a minimum load requirement of 7A on the 5v line (35W). Modern supplies are going to have much lower minimums, but pulling only 0.5W from a 300W is going to be problematic. Is the PC case/power supply still part of the plan?

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On 4/13/2022 at 10:26 AM, SolidState said:

Is the PC case/power supply still part of the plan?

There was a case being planned see 

 but it was later shelved 😞 . Search the forum for more info.  I assume that the prototype boards are being run off of modern productized supplies, so I don't have a concern that when the X16 ships that one would have to source/construct a custom supply. 

 

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On 4/13/2022 at 11:51 AM, SolidState said:

I'm not too sure. I took a couple of screenshots of the prototype board in action.

those appear to be some sort of unit - I think I saw one being used/explained in a video somewhere.

 

In the opening of Adrian's X16 video it appears he's using a standard power supply - 

 

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I probably need to update this thread now that my Breadboard 6502 "X16 Compatible" is nearing completion, after adding the audio components, the power consumption shot WAY up. Currently at 4MHz with both VERA and YM2151 generating audio, I'm measuring 500mA - or about 2.5W. I don't have the tooling to measure component-by-component to see where all that power is getting consumed, but it jumped after the Audio, OpAmps, and DACs were added. The YM2151 is warm to the touch (not hot, but not room temp either) so I figure that's one major culprit.

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On 4/18/2022 at 2:02 PM, Wavicle said:

I probably need to update this thread now that my Breadboard 6502 "X16 Compatible" is nearing completion, after adding the audio components, the power consumption shot WAY up. Currently at 4MHz with both VERA and YM2151 generating audio, I'm measuring 500mA - or about 2.5W. I don't have the tooling to measure component-by-component to see where all that power is getting consumed, but it jumped after the Audio, OpAmps, and DACs were added. The YM2151 is warm to the touch (not hot, but not room temp either) so I figure that's one major culprit.

Some solid numbers. 👍

That's still less power than a modern USB power adapter will supply (the current norm is > 2A for Apple and Android units, with Power Delivery units able to go much higher.) 

I use one of these on my MiSTer, fed from a 19.5v laptop power adapter:
https://www.amazon.com/gp/product/B07VNDGFT6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

So for those low power draws, you can use just about anything. 

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Recently I needed some compact PSU, I found some and I decided to share, because I think these might be some good options for X16.

1. Usual Pico PSU: https://www.amazon.com/Mini-Box-picoPSU-160-XT-Power-Mini-ITX-Supply/dp/B005TWE6B8

2. Something like Pico PSU, also powers from external brick, but board is bigger, and delivers more amps (Chieftec Adapter + DC to DC SERIES / CDP-120ITX): https://www.chieftec.eu/products-detail/193/Adapter___DC_to_DC_SERIES

3. ATX internal PSU box, but smaller in size then usual (Chieftec SMART SERIES / different models from 250W to 400W): https://www.chieftec.eu/products-detail/189/SMART_SERIES/273/GPF-350P

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