exxos's Atari, Amiga & retro forum

With my Atari STE I use a ACSI2STM sd card hard drive adapter. The latter needs a seperate 5v power supply. I guess having the extra 5V power supply is making the OLED display on my gotek usb floppy drive blank out. A single power supply would be better. But I don't think the standard Atari STE power supply is up to it. From ebay would a Astec SA40-1313 power supply https://www.ebay.co.uk/itm/154733101712 ... nl%3Dmkcid be good enough to power the STE with the ACSI2STM? I also would have to fit the Astec power supply on the Atari STE power supply metal riser. And run a pair of power wires from the rear of the Atari STE case to the ACSI2STM

I'm not sure why you think the ACSI2STM power supply is making the Gotek OLED display blank out?

Can you explain further what is exactly happening and include pictures of your setup, but I think it unlikely that an external PSU connected to the SD adapter would affect the Gotek display.

ACSI2STM draws hardly any power. A gotek draws a lot less than a hardware floppy. You can safely use the original supply if it's in good condition.

I run my ACSI2STM from a dupont wire clip routed out through the DMA port.




The most I've seen ACSI2STM draw is 50mA working flat out.




BW

From your example I did a wire connection from the 5V output on the Atari STE standard power supply to to 5V pin on the STM32 blue pill that is part of the ACSISTM. This powered the ACSISTM but it was not recognized by the Atari STE as a hard drive. When I got my ACSISTM I found out none of my 5V USB chargers could provide enough power to the ACSI2STM. I have to use a DLINK 5V 1.2 amp psu for it to properly work.

This is a oscilloscope measurement of the Atari STE power supply. There is a peak to peak difference of 217 millivolts.

Hmm. Something not quite right there, for sure. Partial short or failed regulator?

I'm powering two LDO regulators (one on the blue pill, one on the SD card module) happily with that dupont cable.

In a previous test I was able to take the voltage on the 5V line (really just an input to the LDO) down to ~3.8V and it still was enough for the ASCI2STM to work, although I didn't test the SD card module (that would load it more as I've stupidly got a 5V module. The SD card is 3V3 anyway -- I have a new module on order).

Since you mention problems with your Gotek screen too, perhaps there is something else going on. But if that measurement of your PSU is under normal load, it should be plenty for your needs. Does the ASCI2STM get hot?

BW

Hi,

I have my ACSI2STM powered by a USB port plugged into the cartridge port on my STE. I also have a GOTEK with a large screen fitted. It all works fine.

Not all USB cables worked. It took a bit of trial and error to find one that powered the ACSI2STM.


Matt

I swapped gotek usb floppy drives between the Atari STE and another computer and the Atari STE one is faulty. Not sure what the cause of that failure is so after this testing I won't use the good gotek on the Atari STE any further.

Anyhow I have ordrered the Astec new-used power supply from ebay. Astec power supplies are good quality and are used in Cisco networking gear. I already use a type of Astec psu on a Commodore Amiga and it gives voltages with little ripple\peak to peak difference.

I replaced the standard Atari STE power supply with the Astec SA40-1313 and now the ACSI2STM fully works and boots when powered from the computer with a 5V lead going to the positive connection on the biggest capacitor that is next to the PSU and RAM. From this I now assume the old power supply gave a bad 5v which could have damaged the gotek usb floppy drive. I tested the old 5V line with a oscilloscope but I am a newbie electronics hobbyist and after watching a youtube video about testing for voltage ripple from a psu I now know I need to do some extra stuff to setup the oscilloscope properly.

I could only use one screw to attach the Astec psu to the Atari STE power supply mount but it is fairly secure. And I put electrical masking tape over the other 3 screw holes that were not in alignment with the Astec psu pcb.

So it seems I did some good preventitive maintenance by replacing the original power supply.

Wanting to do the same..

Pull a 5V+ for my ACSI2STM from a Atari STf model

Can someone PLEASE post pics of the wiring?

WilsonB wrote: 06 Nov 2024 07:18 Wanting to do the same..
Pull a 5V+ for my ACSI2STM from a Atari STf model
Can someone PLEASE post pics of the wiring?

There isn't really much to post as everyone's configuration is different.

You tap 5V from somewhere on the motherboard or PSU, you route it out of the case, you attach it to the clearly labelled 5V pin of the Blue Pill, or any other exposed 5V point.

BW