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STFM UBE DUALTOS 2019 with 1.02 -1.04 ROM white screen

Posted: Tue Jan 14, 2020 8:50 am
by nudge
I received and have installed the STFM UBE DUALTOS 2019 with the 1.02 - 1.04 ROM. I set the jumper to run 1.04 in manual mode but it will only boot to GEM desktop if I switch it on and off a few of times. Most boot attempts end in a white screen. What I have found is that the TS pad came pre-soldered which I didn't check before trying to boot the ST. I had not connected the reset to pin 18 of the processor as I only wanted to run in manual. Would the UBE be fried and can I just de-solder the TS pad and still run in manual with 1.04. I've checked the ROM with my TL866 and it seems fine and functional. Board is a C070789 with 1Mb ram in 32 chips and Gotek. No other modes have been installed.

Regards
Nudge

Re: STFM UBE DUALTOS 2019 with 1.02 -1.04 ROM white screen

Posted: Tue Jan 14, 2020 9:38 am
by exxos
Sounds like you have a bad reset circuit. https://www.exxosforum.co.uk/forum/viewt ... =17&t=1585

Re: STFM UBE DUALTOS 2019 with 1.02 -1.04 ROM white screen

Posted: Thu Jan 16, 2020 9:27 am
by nudge
Thank you Exxos for your reply.

I have already replaced the caps in the reset circuit as per your guide. This was done at the same time as the psu and the rest of the motherboard.
I desoldered the TS pad and jumpered bank one, the machine now boots to 1.04 and the reset button works fine. I then did the same test with the jumper in Bank two. Machine booted to 1.02 and the reset works ok.

Tried connecting reset to pin 18 of the 68000, resoldered TS pad and removed jumper. The machine went back to white screen and reset fails to work.
Desoldered TS pad, disconnected wire to pin 18 and reinsalled jumper. machine is now booting and reset works. UBE fried?

Ideas?

Regards
nudge

Re: STFM UBE DUALTOS 2019 with 1.02 -1.04 ROM white screen

Posted: Thu Jan 16, 2020 9:57 am
by exxos
Yeah, asume it killed the chip having the jumper and TS connected at the same time :(

Re: STFM UBE DUALTOS 2019 with 1.02 -1.04 ROM white screen

Posted: Fri Jan 17, 2020 2:00 am
by nudge
No worries. I’m happy running in manual mode or just setting up a toggle switch if need be.

I can replace the UBE. Do I need to get it from here or can I program one myself.

Regards
Nudge

Re: STFM UBE DUALTOS 2019 with 1.02 -1.04 ROM white screen

Posted: Fri Jan 17, 2020 11:39 am
by exxos
I guess you could program the chip yourself if you have the correct hardware. I don't know if @ube Made the file publicly available or not ? I will have the file *somewhere* but I only programmed the chips that one time, so don't remember much about it all now.

Re: STFM UBE DUALTOS 2019 with 1.02 -1.04 ROM white screen

Posted: Sun Jan 19, 2020 5:38 pm
by ube
No black magic or anything... @exxos, which pins are reset and output? In this arduino code PB0 is reset line and PB1 is output.

However! You can't fry the attiny by having TS and jumper at the same time, the attiny can handle 5 volts.

Code: Select all

#include <EEPROM.h>

#define switchTime 2000000


unsigned long buttonPressedTime;


void setup() {
  // put your setup code here, to run once:
  pinMode(PB1, OUTPUT);
  pinMode(PB0, INPUT_PULLUP);
  if ( ! bitRead(PINB, PB0) ) {
    buttonPressedTime = micros();
    while ( ! bitRead(PINB, PB0));
    if ( micros() > switchTime + buttonPressedTime ) {
      int data = EEPROM.read(0);
      if ( ! data )
        data = 1;
      else
        data = 0;
      EEPROM.write(0, data);
    }
  }
  digitalWrite(PB1 , EEPROM.read(0));

}

void loop() {
  // put your main code here, to run repeatedly:
  // Do nothing.
}