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AuthorTopic: Amiga 2000: ATX PSU vs. TICK signal  (Read 2321 times)

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Offline LoadWB

Amiga 2000: ATX PSU vs. TICK signal
« on: August 12, 2007, 06:26:53 AM »
I think AmigaKit mentioned before that the main obstacle to implementing an ATX PSU converter for the 2000 is designing a TICK signal generator.  (I have an mini-ATX PSU in my 4000, and it's great!)

While browsing the A2000 Schematics I noticed J300, which selects between the TICK signal from the power supply and (the schematics are in another room, so I'm relying on recall here)  the VBLANK signal.

Would it be such an issue to use the VBLANK signal in lieu of the missing TICK signal from an ATX power supply?  Wouldn't that only make a difference with the internal clock when the system is in a video signal mode opposite of its native mode (PAL->NTSC, NTSC->PAL)?
 

Offline vk3heg

Re: Amiga 2000: ATX PSU vs. TICK signal
« Reply #1 on: August 12, 2007, 06:35:30 AM »
Quote

LoadWB wrote:
While browsing the A2000 Schematics I noticed J300, which selects between the TICK signal from the power supply and (the schematics are in another room, so I'm relying on recall here)  the VBLANK signal.

Would it be such an issue to use the VBLANK signal in lieu of the missing TICK signal from an ATX power supply?  Wouldn't that only make a difference with the internal clock when the system is in a video signal mode opposite of its native mode (PAL->NTSC, NTSC->PAL)?


I use this method for my A3000. I have a 300w AT power supply, providing power and had to use this jumper on the motherboard.  The ami, works great and as it should (I don't do video work though, and use a cybervision rtg graphics card for non amiga modes).

Amiga 3000: Towered, 12Mb Ram, 9Gig SCSI Hd, Retina BLT Z3, X-Surf, OS3.1
Amiga 4000D: Warp Engine \'040 40Mhz, 150mb Ram, CyberVision 64/4, X-Surf, OS3.9
 

Offline orange

Re: Amiga 2000: ATX PSU vs. TICK signal
« Reply #2 on: August 12, 2007, 07:37:53 AM »
there are simple schematics on aminet for tick signal generator, and here in PROTEL format
Better sorry than worry.
 

Offline Andeda

Re: Amiga 2000: ATX PSU vs. TICK signal
« Reply #3 on: August 12, 2007, 07:11:26 PM »
I have a ATX powersupply in my A2000 because my old PSU was overloaded, and i use "internal tick" and it works fine for me.  :-)
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