Page 4 of 5

Re: ST536NG build

Posted: 05 Dec 2025 10:20
by exxos
HigashiJun wrote: 05 Dec 2025 01:34 @exxos

Here's something that might interest you
Oh cool thanks.. Looks like he has a few auctions open as well.. I will try and remember to bid!!

Re: ST536NG build

Posted: 05 Dec 2025 10:26
by JezC
exxos wrote: 05 Dec 2025 10:20
HigashiJun wrote: 05 Dec 2025 01:34 @exxos

Here's something that might interest you
Oh cool thanks.. Looks like he has a few auctions open as well.. I will try and remember to bid!!
I'd be interested in one of those as well...would it be worth buying a couple to reduce overall postage costs maybe?

Re: ST536NG build

Posted: 05 Dec 2025 10:47
by HigashiJun
@exxos @JezC

The seller has another one for sale:

https://www.ebay.com/sch/i.html?item=25 ... n=kjrind01

Re: ST536NG build

Posted: 05 Dec 2025 10:53
by exxos
HigashiJun wrote: 05 Dec 2025 10:47 @exxos @JezC

The seller has another one for sale:

https://www.ebay.com/sch/i.html?item=25 ... n=kjrind01
Looks like someone else is very determined, so unfortunately I think I will pass... :(

Capture.PNG

Re: ST536NG build

Posted: 05 Dec 2025 11:10
by HigashiJun
exxos wrote: 05 Dec 2025 10:53 Looks like someone else is very determined, so unfortunately I think I will pass... :(
Yeah, the item is getting pricey...

Re: ST536NG build

Posted: 05 Dec 2025 11:26
by JezC
exxos wrote: 05 Dec 2025 10:53
HigashiJun wrote: 05 Dec 2025 10:47 @exxos @JezC

The seller has another one for sale:

https://www.ebay.com/sch/i.html?item=25 ... n=kjrind01
Looks like someone else is very determined, so unfortunately I think I will pass... :(
Yeah, me too!

Re: ST536NG build

Posted: 08 Dec 2025 11:58
by spen
The new xc95288xl board is not booting, not even a flicker of life today.

I've ran the same CPU and same ZIF socket in a working xc95144xl based ST536 for several hours without any issue. I used a storm ST to provide the modified TOS2.06 image.

Swapping out the xc95144xl ST536 for the new xc95288xl board but keeping the same rom image, same storm ST, same MegaST, same CPU, same socket resulted in nothing. The 288 flashed no problem with the beta firmware.

IMG_9247.jpeg
8Mhz clock looking good.
IMG_9248.jpeg
generated E signal at 800Hz, so I think the CPLD is ok, or at least running. how is E derived, just the 68000 clock /10?

All 68000 address lines are quiet, all 68000 data lines are again quiet. Reset drops active for a brief moment.

Getting to the 68030 clock, the oscillator and the bus transceiver underneath whilst it's in the machine and its switched on is going to be fun.

Re: ST536NG build

Posted: 08 Dec 2025 12:03
by exxos
@spen Have you done the mods and using the latest firmware ? If you just put the latest firmware in without doing the mods,you be shorting out the clocks!

EDIT:

I don't know if external decoders will work either.. IIRC the firmware disables motherboard ROM access.. so your likely introducing a new problem there by not using the intended ROM on the 536..

Re: ST536NG build

Posted: 08 Dec 2025 13:13
by spen
exxos wrote: 08 Dec 2025 12:03 @spen Have you done the mods and using the latest firmware ? If you just put the latest firmware in without doing the mods,you be shorting out the clocks!

EDIT:

I don't know if external decoders will work either.. IIRC the firmware disables motherboard ROM access.. so your likely introducing a new problem there by not using the intended ROM on the 536..
It's not the STE536 with the funky adapter pins. It's an ST536 2025 edition and fits in a DIP socket. I can see 8Mhz at the CPU CLK pin with reset button held in, and 50Mhz when released. The CLK looks ok???? The 50Mhz clock is a smaller amplitude. I can put a resistor between '030 CLK and GND. I can't do the other mod - the pictures don't correspond to my board and my oscillator is not on a daughter board.

I'll look for a 16bit rom, it'll be vanilla tos2.06 if I can find it. <<<< No change when using onboard rom

Re: ST536NG build

Posted: 08 Dec 2025 13:40
by exxos
spen wrote: 08 Dec 2025 13:13 It's not the STE536 with the funky adapter pins. It's an ST536 2025 edition and fits in a DIP socket.
Makes no odds, you need to do the clock mods and use the onboard ROM.
I can see 8Mhz at the CPU CLK pin with reset button held in, and 50Mhz when released. The CLK looks ok????
You won't have a SDRAM clock which will prevent you from booting most likely.
I can't do the other mod - the pictures don't correspond to my board and my oscillator is not on a daughter board.
I'm not sure your looking at the right page ?

https://www.exxosforum.co.uk/atari/last/ST536/index.htm