shugs81
Posts: 25
Joined: Wed Aug 14, 2013 11:46 pm

Dos pc emulator - Using a 4b with 4gb ram

Fri Feb 14, 2020 5:23 pm

Hi chaps.

I'm planning to build a Raspberry pi 4 based dos gaming machine and typically as I've just bought 2 boards I've just found out about the usb c issues...

Can i ask... is the c port just for power? or does it do anything else? and as I'm going to be putting in its own little case n stuff can i remove it and just wire power up to where it needs to be?

Another thing is i'll be using the GPIO pins for RGB out for the pi... can i use the gpio pins for both the output to rgb and power in?

or have i just massively shot myself in the foot buying these?

Thanks

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B.Goode
Posts: 10727
Joined: Mon Sep 01, 2014 4:03 pm
Location: UK

Re: Dos pc emulator - Using a 4b with 4gb ram

Fri Feb 14, 2020 5:31 pm

shugs81 wrote:
Fri Feb 14, 2020 5:23 pm
Hi chaps.

I'm planning to build a Raspberry pi 4 based dos gaming machine and typically as I've just bought 2 boards I've just found out about the usb c issues...

Can i ask... is the c port just for power? or does it do anything else? and as I'm going to be putting in its own little case n stuff can i remove it and just wire power up to where it needs to be?

Another thing is i'll be using the GPIO pins for RGB out for the pi... can i use the gpio pins for both the output to rgb and power in?

or have i just massively shot myself in the foot buying these?

Thanks

The pins on the 40-way header of your RPi 4 board can be grouped into a number of categories. Only 26 are GPIO connections. These are only 3.3v safe, so cannot be used to supply 5v power to the RPi board.

With early models of RPi it used to be possible to connect a VGA add-on board to generate a VGA display from the gpio pins of an RPi board - I don't know if that is still viable with a current RPi4 board.


Edit: added later - I don't understand how you think a minor implementation issue concerning the use of non-RPi power supplies is relevant to using a DOS emulator. Particularly if you don't intend to use that usb power connector...
Last edited by B.Goode on Fri Feb 14, 2020 5:45 pm, edited 1 time in total.

fruitoftheloom
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Location: Delightful Dorset

Re: Dos pc emulator - Using a 4b with 4gb ram

Fri Feb 14, 2020 5:31 pm

shugs81 wrote:
Fri Feb 14, 2020 5:23 pm
Hi chaps.

I'm planning to build a Raspberry pi 4 based dos gaming machine and typically as I've just bought 2 boards I've just found out about the usb c issues...

Can i ask... is the c port just for power? or does it do anything else? and as I'm going to be putting in its own little case n stuff can i remove it and just wire power up to where it needs to be?

Another thing is i'll be using the GPIO pins for RGB out for the pi... can i use the gpio pins for both the output to rgb and power in?

or have i just massively shot myself in the foot buying these?

Thanks

The Raspberry Pi SBC has Composite Out on the TRRS4 A/V Socket.

https://thepihut.com/products/av-compos ... 3-x-rca-3m


Regards powering via the Header Pins:

viewtopic.php?f=91&t=248215&p=1515523
Thinking outside the box is better than burying your head in the sand...

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rpdom
Posts: 17736
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Dos pc emulator - Using a 4b with 4gb ram

Fri Feb 14, 2020 5:38 pm

The USB-C socket can handle both power and data.

The GPIO pins can be set to provide a DPI video interface that can drive some screens directly or through a buffer circuit, or the aforementioned VGA adaptor.

You can also provide 5V power through the power pins on the 40-way connector at the same time.
Unreadable squiggle

shugs81
Posts: 25
Joined: Wed Aug 14, 2013 11:46 pm

Re: Dos pc emulator - Using a 4b with 4gb ram

Mon Feb 17, 2020 12:30 pm

Thanks for the replies guys..

I'm glad that the usb-c isn't the big issue it seemed to be! phew...

i was just worried that i wouldnt be able to use it for what i wanted to because the gpio pis will be used for the rgb adaptor...

Thanks again... will probs post with more problems down the line..

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