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- Thu Feb 08, 2024 12:42 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
ps. Not sure why the forum rotates the image?
- Thu Feb 08, 2024 12:36 pm
- Forum: ST536 030 ST ACCELERATOR
- Topic: ST536 - Build in progress
- Replies: 10
- Views: 648
Re: ST536 - Build in progress
Nice setup with the camera. Which model is it ?
- Thu Feb 01, 2024 9:47 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
Alright. As it is now is that there is a white screen and a double buss error so the CPU goes into a halt. Ive tested with a Atari Diagnostic cart but it does not show up on the screen or output anything on the serial. Ive read the Atari 520st - 1040st service manual (the motherboard is a stfm) and ...
- Wed Jan 24, 2024 10:28 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
Yeah the signals look fine to me atleast, except for csync. Csync is between -1v to +1v.
The screen is rolling vertically and are displaying different shades of black/grey.
/zChris
The screen is rolling vertically and are displaying different shades of black/grey.
/zChris
- Wed Jan 24, 2024 9:54 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
Yeah that i know i just wanted to have a clear white picture atleast
/zChris
/zChris
- Wed Jan 24, 2024 9:28 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
Alright, it seems that i have this issue https://exxosforum.co.uk/atari/last/STF ... /index.htm (among others). Im using a scart cable that works (tested with other ataris). My question is if i cant just redirect HSYNC to pin 2 (pin 20 on the scart) and skip CSYNC ?
/zChris
/zChris
- Fri Jan 19, 2024 10:43 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
Alright i have been doin the tests that have been suggested to troubleshoot a H4 motherboard ( https://www.exxosforum.co.uk/forum/viewtopic.php?f=78&t=2362 ). I'll post the results here if someone maybe see something obvious that im too new to see. Something i noticed was that som Dx and Ax adre...
- Thu Jan 18, 2024 10:09 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
Here are the CLOCKs measurements. EDIT: Made a misstake and measured the wrong Pin on GLUE 8MHZ. The correct pin measures correctly M68000K Pin 15 (DEFAULT 8Mhz) M68000Pin15.png SHIFTER Pin 2 (DEFAULT 32Mhz) ShifterPin2.png Pin 39 (DEFAULT 16Mhz) ShifterPin39.png MMU Pin 5 (DEFAULT 16Mhz) MMUPin5.pn...
- Thu Jan 18, 2024 8:08 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
The oscilioscope im using is DS1052E 2channel 50Mhz 1GSa/s.
/HALT goes high then low on a power on. It react on RESET.
OE (Pin 22 on the roms L0-L2, H0-H2) is always low.
/zChris
/HALT goes high then low on a power on. It react on RESET.
OE (Pin 22 on the roms L0-L2, H0-H2) is always low.
/zChris
- Thu Jan 18, 2024 7:41 pm
- Forum: NOOB QUESTIONS
- Topic: Atari 520 STFM faulty - Project
- Replies: 17
- Views: 1257
Re: Atari 520 STFM faulty - Project
Ive measured what you suggested @stephen_usher and here is the results:
Pin 49 VCC 5.2V
Pin 14 VCC 5.2V
Pin 15 CLK 7.813 -8.065 Mhz
Pin 17 HALT Logical Low (240mV)
Pin 18 RESET Logical High (4.08V)
Here is an image on the CLK and it doesnt look good? Never got a stable curve. /zChris
Pin 49 VCC 5.2V
Pin 14 VCC 5.2V
Pin 15 CLK 7.813 -8.065 Mhz
Pin 17 HALT Logical Low (240mV)
Pin 18 RESET Logical High (4.08V)
Here is an image on the CLK and it doesnt look good? Never got a stable curve. /zChris