exxos's Atari, Amiga & retro forum

Better (desoldered and resoldered the oscillator). Still no output on CLKOUT though. Tried just hooking up 3.3V to the input and the output did respond. Didn’t connect it through a 10k resistor, though.

Might just have to order some new buffers to make sure I have the right components.

My bad. I DO have some output on CLKOUT. Weird-ass output.
For comparison; here's CLKOUT when JP1 is set to the 7 MHz clock:

I had the same problem with my TF530, it wouldn’t boot. No clock signal. Turned out to be a short on the BUS CPLD. I reflowed it and my Amiga booted with the TF530 at 50 mhz.

redhawk668 wrote: 07 Mar 2019 20:01 I had the same problem with my TF530, it wouldn’t boot. No clock signal. Turned out to be a short on the BUS CPLD. I reflowed it and my Amiga booted with the TF530 at 50 mhz.

But then I wouldn’t get a clock signal when the jumper is set to 7 MHz either, right?

The clock topology was one of the major reasons for the TF534.

terriblefire wrote: 07 Mar 2019 21:18 The clock topology was one of the major reasons for the TF534.

But I’m damn sure I want this to run! Will I damage the 3.3V stuff if I hook up a 5V oscillator instead? I was thinking if I could use the signal from the 28 MHz one from the Amiga to check if everything else is working.

nothing will get damaged by a 5V osc... but you will make the reflection problem worse

terriblefire wrote: 07 Mar 2019 22:09 nothing will get damaged by a 5V osc... but you will make the reflection problem worse

Ah. Would it be possible to add some kind of termination on the signal if that is the case? I don’t mind dead bug-ing the hell out of this board. I am kludge, after all ;)

Come to think of it, I have a pile of 50 MHz 5V oscillators that I ordered by mistake. But 50 MHz AND 5V might be pushing it.

The 10K resistor was there to not damage anything as you do not know where te problem is.

Please leave the A500 oscillator alone, you are only getting further down the rabbit hole.

P.s. witch 68030 did you get? 33c? , that could probably run on 50Mhz...., just remove the coprocessor if it is slower than 50Mhz



If you have to wait for parts i have an Idea... :twisted:
1. Take the 50Mhz 5v Oscillator and test it on 3v, if it runs you are in luck and you can use it on 3,3v.
2. Put the above on a piece of perfboard with frequency divider using a d-flip flop on 3,3v , and then you have 25Mhz.
(don't forget a 19Uf cap across VCC and GND)
3. Test

4. Put on your new Oscillator on when it arrives.

kludge wrote: 07 Mar 2019 22:12

terriblefire wrote: 07 Mar 2019 22:09 nothing will get damaged by a 5V osc... but you will make the reflection problem worse

Ah. Would it be possible to add some kind of termination on the signal if that is the case? I don’t mind dead bug-ing the hell out of this board. I am kludge, after all ;)

Come to think of it, I have a pile of 50 MHz 5V oscillators that I ordered by mistake. But 50 MHz AND 5V might be pushing it.

There is a resistor pad in the Rev 3 for this purpose. North of the RaM cpld next to the SPI port.

I’d also recommend putting the FPU in if you haven’t already. It has the same effect