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eightbit

SDrive Max power question

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So I have decided to purchase an Sdrive Max pre-built (as I have no access to 3D printers for the case, etc...and the price was right at $50 done already) from a seller on ebay. There were two sellers on ebay selling these and both are providing USB as a way to power the drive.

 

But, I am finding people in forums (here too) saying that powering over USB is not supposed to be used as the USB power is only for when it is connected to a PC for flashing.

 

Then I read a 12V 1A center pos 2.1mm power supply should be used. Then I am reading somewhere else that 12V is overkill and will lessen the life of the unit and that 9V 1A should be used.

 

 

Yeah, reading alot. Ugh!

 

So, quiet simply can someone with the right knowledge answer this question and perhaps point me to the power supply that they use? Or is the USB actually OK to use?

 

Forgive me, I just received a nice 800XL after not owning one in many years and a lot has changed since I was using RS-232 serial to SIO adapters ;)

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Thanks for the responses guys! I wonder what all of the hoopla is about not using the USB then? If you guys say its ok I will just do it that way!

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Very cool. Now, when you use the USB on this (or any power for that matter) is it "always on"? In other words, I either have to connect it to a USB on/off switch or unplug the USB wall wart connected to it in order to power it off? I do not have the device yet obviously but am trying to be prepared. Thank you for the responses! I really love the Atari 8-bit home computers and this device really looks great!

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9 hours ago, eightbit said:

Thanks for the responses guys! I wonder what all of the hoopla is about not using the USB then? If you guys say its ok I will just do it that way!

Its from people who don't really understand and make assumptions, the Arduino is meant to be powered by it's USB connection.

 

I have my SDrive connected to one of those mains extension leads that also has USB power outputs

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The UNO can be powered through the power jack using 5v-12v without problems, from the usb socket with 5v and from a couple of GPIO pins with 5v. all of these methods are fine. The UNO screens use a varying amount of power (up to 200ma) depending on the screen type and manufacturer. 

 

The Atari SIO is rated to output 5v at 50ma, for some screens this is enough, for some it's not. Some Ataris can output more than 50ma so they can also handle the screens that use more. Some people use more than one device on the SIO and some people use more than one SIO powered device on the SIO for some people Atari power is enough, for some they hit limits.

 

Some people are worried they might be shortening the life of their Atari by sucking so much power for long periods.

 

Some people play it safe and use USB or external power just to avoid the worry.

 

 

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It's funny so much misinformation is out there. Glad you guys are hear to set the record straight :) I will just use the USB with a phone USB power brick. Thanks all and Happy Thanksgiving!

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I currently have all of mine set to use SIO power, I may have to reconsider and use USB - will help especially as it will always be on rather than at power up

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Hi,

 

  Just to clear up the wiring for the SIO connector, if you are powering an SDrive Max from USB or the Arduino power connector, should you make sure *not* to connect the SDrive Max to the SIO power line (pin 10 +5v/Power)? That is:

 

   - only connect the SIO power on pin 10, or

   - only use USB power or Arduino power socket power

    - not both at the same time

 

    I think I may have been having power level issues with the two SDrive Maxes I have built, one setup worked fine, one was white screening (on the same system), but the second Arduino had issues with the firmware flashing, so I've just managed to reset it via ICSP, and am going to have another go at building the perfboard SIO fixup circuit. 

 

   Incidentally, the original perfboard prototype by @BigBen drew its power from pin 10 (judging by the photos), should you also not connect SIO pin 10 if you have this upgrade/fix?

 

   Thanks!

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@E474 Yes the original perfbord is powered from pin 10 of the SIO, so are the first few versions of my pcb. I added a jumper on v3 so it can be switched.

 

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I would like to try my Sdrive Max with a 1200XL. I know I must use an external power in this case. But there seems to be contradictory information. A standard 5V 1A USB power supply with a USB-to-barrel adapter is enough? Or you need a 9V-12V PSU?

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On 11/28/2019 at 12:20 AM, DrVenkman said:

USB power is fine, as is a standard Arduino UNO 9V PSU. 

 

There was somebody claiming that it can't be powered through USB except for configuring the UNO:

 

 

So that was wrong? It is fine to just power the USB connector?

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You can't externally power (USB/9v) and internally power (SIO) at the same time. Plugging the sdrive into a USB connection while attached to the SIO (and powered through it) is a bad idea. there is a switch on the sio2uno board to disconnect the SIO power for exactly this reason.

 

Once disconnected from SIO power it's fine to power through USB or 9v, whichever you prefer.

 

Edited by Mr Robot
Spellz

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4 minutes ago, Mr Robot said:

You can't externally power (USB/9v) and internally power (SIO) at the same time. Plugging the sdrive into a USB connection while attached to the SIO (and powered through it) is a bad idea. there is a switch on the sio2uno board to disconnect the SIO power for exactly this reason.

 

I see, many thanks.

 

Quote

Once disconnected from SIO power it's fine to power through USB or 9v, whichever you prefer.

 

So 9V is the minimum when using the jack connector, 5V is not good enough (I guess there is a regulator that requires at least 9V)?

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32 minutes ago, ijor said:

So that was wrong? It is fine to just power the USB connector?

 

See below.

 

11 minutes ago, Mr Robot said:

Once disconnected from SIO power it's fine to power through USB or 9v, whichever you prefer.

What he said. :)

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my experience has been SIO power or Barrel connector... USB even with the switch was sketchy... of course I had multiple cheap boards from china... you mileage and noise may vary.... I'd finally just settled on the 9v barrel connector only set up because you don't know how many SIO powered devices a person has, or their Atari power brick situation and any mods in their machine has. Safer than sorry... that's for me.

Edited by _The Doctor__

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44 minutes ago, ijor said:

So 9V is the minimum when using the jack connector, 5V is not good enough (I guess there is a regulator that requires at least 9V)?

Using the barrel connector you can use anything from 7 to 12v

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2 hours ago, ijor said:

I would like to try my Sdrive Max with a 1200XL. I know I must use an external power in this case. But there seems to be contradictory information. A standard 5V 1A USB power supply with a USB-to-barrel adapter is enough? Or you need a 9V-12V PSU?

I use my Sdrive with a 1200xl and no external power. Why would it supposedly not work?

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39 minutes ago, Frankie said:

I use my Sdrive with a 1200xl and no external power. Why would it supposedly not work?

 

Really? A stock 1200XL without the SIO 5v mod? It should not work because the 1200XL, and only the 1200XL, doesn't provide much power over SIO. Most peripherals that are SIO powered don't work on the 1200XL for that reason.

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8 hours ago, Frankie said:

I use my Sdrive with a 1200xl and no external power. Why would it supposedly not work?

A stock 1200XL has a current-limiting resistor on the +5V SIO line. I don’t recall the value off hand but that resistor means than many SIO-powered devices don’t work correctly or at all when plugged into a 1200XL, unless that resistor is removed and replaced with a jumper wire or 1-ohm resistor instead. 

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A quick not technical run down with plenty of missing parts and scenarios to give a general idea ....

There are a lot of scenarios around this.

Since they are built using a number of different screens, boards, with different switches, isolation scenarios, sio wiring, modified Atari's done in various ways, not to mention displays from Atari... you can do it whatever way you wish.

--- on with it---

The problem is when any of that changes...

 

let's say the Atari you now hook it to has the smaller current output supply (a new machine or you took the Sdrive-max to your buddies house) ... the Sdrive-starts acting poorly.

or lets say you add a rambo or newell memory upgrade, and suddenly the supply isn't good with the SIO chain... same thing...

---

You can get a better Atari power supply --- you can add super caps --- etc.

---

The standard SDrive-Max SIO powered without caps doesn't always boot up proper at power on/cycle, and you can't pre-select at a brand new cold sit down situation as nicely, you have to power on the Atari select/configure save reboot.

So some guys have super capacitor in their unit to allow for brief power off and on.... etc etc...

The USB issue required the switch mod, and there were more than one scenarios that this was an issue... scan the threads for some that were posted here on AA... there are others on different forums... and private email as well... power, programming, noise, being some of the highlight... not all USB power supplies are created equal...

--- you can get a better usb supply--- you can add a switch--- you can add protection diodes--- you can---

 

Some people have modified their computer that do not have SIO power included or limited, some do a proper job using the lowest drop diode they can find, other just replace it with wire or leave it in place and then jump the resistor

 

The last issue I had someone tell me about was SIO power, no caps, saving their work and powering off too quick... the SDrive was not able to save it's buffer before shut down. Super Caps would have helped... or external power... or waiting then powering off. (a real drive has a prominently displayed busy light and normally no real buffer so it makes noise while working/ sdrive is silent, has a buffer, with most cover/cases you can't see the busy light)

 

Or...

You build it with SIO protection and use the barrel power supply and forget about all that....

 

l like it simple, safe, bulletproof, and in it's most usable form. Sure you'll get all kind of if you understand this then do that stuff...

 

Just walk up, set what you want, boot the machine, do your thing... save if you need too and power off. No lost or scrambled data, noise, backflow, waiting rebooting or other issues. Better yet, no emails, phone calls, etc on what this or that may be. No need to worry about any of those 'quirks'

Edited by _The Doctor__

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