Title: Cube - ATX Supply adapter
Post by: chrisrot on January 25, 2020, 02:27:01 PM
Post by: chrisrot on January 25, 2020, 02:27:01 PM
Hi,
I wanted to replace my old cube supply by a ATX. Based on the Brian's design (http://www.asterontech.com/Asterontech/cube_atx.html) I made a little PCB with some small enhancements.
I replaced the ATmega with an ATtiny and added handling of the "Power On" signal.
I tested it with my cube main board and everything seems to work.
It fits nicely in the case of the old supply. However, I'm not sure how to mount the new power supply yet. Probably I'll use some sheet metal.
Attached are the KiCad and Atmel Studio files. Please feel free to use them, but I can give absolutely no warranty.
One word on the ATX supply: I suggest to use a high quality supply with a dc-dc converter for 5V line like many 80 plus gold types.
ciao
Christoph
NeXTpowersupply_code.zip
next_powersup_kicad.zip
I wanted to replace my old cube supply by a ATX. Based on the Brian's design (http://www.asterontech.com/Asterontech/cube_atx.html) I made a little PCB with some small enhancements.
I replaced the ATmega with an ATtiny and added handling of the "Power On" signal.
I tested it with my cube main board and everything seems to work.
It fits nicely in the case of the old supply. However, I'm not sure how to mount the new power supply yet. Probably I'll use some sheet metal.
Attached are the KiCad and Atmel Studio files. Please feel free to use them, but I can give absolutely no warranty.
One word on the ATX supply: I suggest to use a high quality supply with a dc-dc converter for 5V line like many 80 plus gold types.
ciao
Christoph
NeXTpowersupply_code.zip
next_powersup_kicad.zip
Title: Re: Cube - ATX Supply adapter
Post by: barcher174 on January 25, 2020, 02:44:52 PM
Post by: barcher174 on January 25, 2020, 02:44:52 PM
Looks good!
Title: Re: Cube - ATX Supply adapter
Post by: barcher174 on January 25, 2020, 07:49:08 PM
Post by: barcher174 on January 25, 2020, 07:49:08 PM
One thing I never mentioned on my site is the reset line on the back plane. It should be held and then released on power up. Did you happen to account for this? If you find sporadic cases of the machine booting to a black screen, this is the cause.
Title: Re: Cube - ATX Supply adapter
Post by: chrisrot on January 26, 2020, 02:02:11 AM
Post by: chrisrot on January 26, 2020, 02:02:11 AM
There two signals according to the bus specification (http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/NeXTbus-NBIC/NeXTbus_Specification.pdf), page 2-3: Reset and Power On
Reset is pulled to +5V via 470R.
Power ON should be held low as long as the +5V is below a certain threshold and pulled to +5V via 470R otherwise.
I use the PowerGood signal from the ATX supply to gain this information. The µC pulls Power On low as long as the supply is turned off and pulls it up after PowerGood becomes high with a delay of 500ms.
Reset is pulled to +5V via 470R.
Power ON should be held low as long as the +5V is below a certain threshold and pulled to +5V via 470R otherwise.
I use the PowerGood signal from the ATX supply to gain this information. The µC pulls Power On low as long as the supply is turned off and pulls it up after PowerGood becomes high with a delay of 500ms.
Title: Re: Cube - ATX Supply adapter
Post by: msch on February 22, 2020, 02:54:51 PM
Post by: msch on February 22, 2020, 02:54:51 PM
Hi Christoph,
Great project. Is it possible to get a ready built unit from You?
Best regards
Mathias
Great project. Is it possible to get a ready built unit from You?
Best regards
Mathias
Title: Re: Cube - ATX Supply adapter
Post by: chrisrot on February 23, 2020, 01:54:21 AM
Post by: chrisrot on February 23, 2020, 01:54:21 AM
Hi Mathias,
unfortunately I can't do ready built units for a few reasons.
- First, one need an old (preferably dead) NeXT cube supply as housing
- I didn't solve the mounting of the ATX supply yet. My mechanics skills are quite limited ;-)
- Also one can't "sell" ready made units without the proper regulatory stuff here in Germany
However, I might could do a few mounted PCBs if there's interest.
As you life close to me (I'm a bit south of Darmstadt) I could also help to fit it into your cube.
ciao
Christoph
unfortunately I can't do ready built units for a few reasons.
- First, one need an old (preferably dead) NeXT cube supply as housing
- I didn't solve the mounting of the ATX supply yet. My mechanics skills are quite limited ;-)
- Also one can't "sell" ready made units without the proper regulatory stuff here in Germany
However, I might could do a few mounted PCBs if there's interest.
As you life close to me (I'm a bit south of Darmstadt) I could also help to fit it into your cube.
ciao
Christoph
Title: Re: Cube - ATX Supply adapter
Post by: msch on February 23, 2020, 05:54:46 AM
Post by: msch on February 23, 2020, 05:54:46 AM
Hi Christoph,
I am interested and I will drop You a PM :-)
I am interested and I will drop You a PM :-)
Title: Re: Cube - ATX Supply adapter
Post by: oneNeXT on March 19, 2020, 09:16:39 AM
Post by: oneNeXT on March 19, 2020, 09:16:39 AM
I'm also interrested !
Title: Re: Cube - ATX Supply adapter
Post by: chrisrot on March 19, 2020, 01:41:59 PM
Post by: chrisrot on March 19, 2020, 01:41:59 PM
Hi,
thanks for your interested.
I was planning to do a batch of pcb. Due to the current situation it dropped down on my priority list a bit...
However, if you are intested in a bare PCB or a populated one, drop me a line. I'll try to track the interest in this thread.
Right now:
2x populated - msch
how many ? - one NeXT
thanks for your interested.
I was planning to do a batch of pcb. Due to the current situation it dropped down on my priority list a bit...
However, if you are intested in a bare PCB or a populated one, drop me a line. I'll try to track the interest in this thread.
Right now:
2x populated - msch
how many ? - one NeXT