Search found 644 matches

by Arne
Sun Jan 19, 2020 9:15 pm
Forum: Hardware
Topic: Atari 520ST black screen with white border
Replies: 10
Views: 1924

Re: Atari 520ST black screen with white border

/RESET and /HALT should go high in conjunction after reset button was released. I will take a screenshot of my scope with these signals tomorrow.
Check the clock tree. Maybe MMU does not output 8MHz or does not receive 16Mhz from Shifter or....
by Arne
Sun Jan 19, 2020 5:44 pm
Forum: Hardware
Topic: Atari STFM dead
Replies: 17
Views: 3397

Re: Atari STFM dead

aszasza wrote:the one I used is actively driving the reset line high or low and it works just fine of course.
/RESET line is bi-directional :!: Think about it.
by Arne
Sun Jan 19, 2020 7:17 am
Forum: Hardware
Topic: Atari 520ST black screen with white border
Replies: 10
Views: 1924

Re: Atari 520ST black screen with white border

I forgot to mention: what about /RESET and /HALT on the CPU? These should go low when pressing the Reset button and then back to high. Is there activity on CPU's /AS, /UDS and /LDS lines when releasing the Reset button? CPU will try to read SP from address $0 first so it is a typical read access. Yo...
by Arne
Sat Jan 18, 2020 7:23 am
Forum: Hardware
Topic: Atari 520ST black screen with white border
Replies: 10
Views: 1924

Re: Atari 520ST black screen with white border

ROM2 on the GLUE is high. Is it constantly high - all the time? There should be at least four low pulses (CPU fetching 32bit SP and 32bit PC = four 16bit accesses). Check the PCB trace of /ROM2 and look at Glue's PLCC socket if that pin has contact. I have no SC1224 at hand. Try pulling all TOS ROM...
by Arne
Fri Jan 17, 2020 9:43 am
Forum: Hardware
Topic: Atari 520ST black screen with white border
Replies: 10
Views: 1924

Re: Atari 520ST black screen with white border

Gonna bring out the logic probe this weekend and check the DRAMs. Good idea. As it seems that all data lines are affected I suggest to look for unusual behaviour on /RAS0 (if it is a "real" 520 with 512KB) otherwise on /RAS1 if it got a memory upgrade using the 2nd bank. Additionally you may check ...
by Arne
Fri Jan 17, 2020 7:38 am
Forum: Hardware
Topic: Atari TT internal/external floppy issues
Replies: 5
Views: 1364

Re: Atari TT internal/external floppy issues

Then I suggest to check the MO (Motor On) signal coming from FDC (pin 20), that runs to an inverter (7406 U405 pin 11) and exits it on pin 10 the same IC. Check the PCB tracks with a multimeter first when TT is powered off. With a FDD attached there needs to be a resistance of ~10KOhm between pin 10...
by Arne
Thu Jan 16, 2020 7:20 am
Forum: Hardware
Topic: Atari TT internal/external floppy issues
Replies: 5
Views: 1364

Re: Atari TT internal/external floppy issues

I've checked it with diagnostic cartridge and on start i've got red screen and wait states off, mcu msb (7) never set, fail at cycle 0xffffffff. That's normal. I think (!) the diag software looks for RAM on an additional VME test-board. If the FDD-LED is not blinking (checking for floppy media chan...
by Arne
Sat Dec 28, 2019 9:00 am
Forum: 680x0
Topic: Get address of label from other source files
Replies: 6
Views: 1335

Re: Get address of label from other source files

I don't know if I got you right. You want some kind of global Get/Set functions for getting/setting variables? If this is the case then you may try to set up your own Trap-Handler (i.e. not BIOS/XBIOS/...) with a function number put on the stack to get/set a certain variable. As shared memory for ex...
by Arne
Fri Dec 27, 2019 10:58 am
Forum: Hardware
Topic: Mega ST, DMA error
Replies: 11
Views: 2247

Re: Mega ST, DMA error

I installed Blitter and Patch How about removing Blitter to keep error sources low? turned off the memory on the motherboard and installed 4MB on MMU and SHIFTER You pulled /RASx and CASx to Vcc via Resistor? replaced the CPU, DMA, FDC stands. stands = sockets? As you have swapped the MMU socket: R...
by Arne
Mon Dec 23, 2019 6:52 pm
Forum: Hardware
Topic: Mega STE Mobo repair - small fault with cartridge port
Replies: 23
Views: 3998

Re: Mega STE Mobo repair - small fault with cartridge port

saulot wrote:Hey, do you have repair manual for mste?
The original Atari manuals are called "Service manual". You may download them from my HP.
by Arne
Sat Dec 21, 2019 8:46 pm
Forum: Hardware
Topic: Atari 1040 STE screen troubleshooting
Replies: 1
Views: 772

Re: Atari 1040 STE screen troubleshooting

Partial overheating?
Looks indeed strange. I'd suggest to use an oscilloscope and check all clocks starting with 32MHz and don't forget HSYNC/VSYNC.
Other option could be to use ice spray on small locations only and see if the display comes back to normal.
by Arne
Sat Dec 21, 2019 9:54 am
Forum: Hardware
Topic: ATARI STE 4 MB 4 Bombs after Memmory Test
Replies: 4
Views: 1056

Re: ATARI STE 4 MB 4 Bombs after Memmory Test

Walli272 wrote: After another reset and swicth of with successfull memory Test Only 4 Bombs ..
My question.... what chip burned out ?

Its atari STE with Tos 2.06 that already worked fine ...4 Mb ram ...
Typical for TOS 2.06 if it cannot access FDD. Check DMA, FDD and 74xx ICs in the schematic (!) vicinity.
by Arne
Sun Dec 08, 2019 8:21 am
Forum: Hardware
Topic: 4xTOS selection for STE?
Replies: 19
Views: 1978

Re: 4xTOS selection for STE?

I can see one solution - your ROM switcher monitors the keyboard, and when detects a right combination it pulls the reset line low and while holding it low changes the ROM select lines (2 highest ROM address lines). On power on it should boot the default ROM. On AVR, after power-on, most GPIO lines...
by Arne
Sat Dec 07, 2019 1:17 pm
Forum: Hardware
Topic: 4xTOS selection for STE?
Replies: 19
Views: 1978

Re: 4xTOS selection for STE?

I would love to be able to switch between 4 256K images (1.06, 1.62 206 and EmuTOS) in my STE with hardware switches. Do you want to use pre-programmed FlashMemories or do you want to flash them while inserted in the STE? Any selector should be designed to only select lines at cold boot so it is no...
by Arne
Fri Dec 06, 2019 3:27 pm
Forum: Hardware
Topic: Hard Drive inside Mega ST4
Replies: 23
Views: 5466

Re: Hard Drive inside Mega ST4

(...)but it's peak power requirements are 710mA@5VDC AND 2000mA@12VDC. It's idle power needs are 510mA@5VDC and 350mA@12VDC. The instructions for the host adapter say to use the extra connector right beside the power connector for the hard drive. But according to the Mega ST Expansion Bus Tech Manu...
by Arne
Tue Dec 03, 2019 8:44 am
Forum: Applications
Topic: TOS Switch and OS behaviour
Replies: 1
Views: 1032

TOS Switch and OS behaviour

Hi folks, I've been thinking about a problem lately. Let's say you have a Dual-TOS (e.g. 1.00 and 1.04) option built in your ST. Now you power on the ST and it boots 1.04. OS code detects that the magic values are invalid and performs a cold boot. After a while you switch to 1.00 and press the reset...
by Arne
Mon Dec 02, 2019 3:19 pm
Forum: Coding
Topic: How to enquire Maddalt() support
Replies: 3
Views: 1537

Re: How to enquire Maddalt() support

ThorstenOtto wrote:GEMDOS functions that aren't available return -32, so just check for that. But where are you calling Maddalt()? I'm not sure whether that will be too late when done from a auto-folder-program or similar.
Thanks. Will check for -32 then.
AUTO folder is the preferred way.
by Arne
Mon Dec 02, 2019 1:16 pm
Forum: Coding
Topic: How to enquire Maddalt() support
Replies: 3
Views: 1537

How to enquire Maddalt() support

Hi,
what is the clean(est) way to check if the OS is supporting Maddalt() calls?
Shall I check if GEMDOS version is >= 0.19 or is there a better way?

Thanks, Arne
by Arne
Sat Nov 30, 2019 8:35 am
Forum: Hardware
Topic: External hard drive - spins down when ST starts up!
Replies: 3
Views: 971

Re: External hard drive - spins down when ST starts up!

I have a Quantum ProDrive LPS270 which doesn't require that patch either. It's not related to certain manufacturers. I think this requirement later came up with SCSI evolution but I'm not sure. Anyway: doing the patch is straight forward: download the 3.06 TOSPatch collection from Markus Heiden's ho...
by Arne
Fri Nov 29, 2019 8:58 am
Forum: Hardware
Topic: External hard drive - spins down when ST starts up!
Replies: 3
Views: 971

Re: External hard drive - spins down when ST starts up!

IIRC you have to patch TOS :( This effect seems to have something to do with SCSI target initiator identification. Do you know about the TOS patch collection from Markus Heiden? https://www.markusheiden.de/atari/tospatch.html What TOS are you using? 3.06UK, 3.06US... ? ;*****************************...
by Arne
Thu Nov 28, 2019 1:57 pm
Forum: Hardware
Topic: Mega ST dead ? Have you seen this before ?
Replies: 12
Views: 2249

Re: Mega ST dead ? Have you seen this before ?

Even if RAM is defective... shouldn't it display a stable screen? At least that's how my F030 behaves. I'd say it should not show these "frayed" borders. Look like HSYNC is out-of-sync. GLUE: HSYNC pin 37, VSYNC pin 38. Check these with an oscilloscope. There is a GAL listing around which re-creates...
by Arne
Wed Nov 27, 2019 1:26 pm
Forum: Hardware
Topic: 1040STf chip location help wanted
Replies: 5
Views: 1067

Re: 1040STf chip location help wanted

Arne; Yes, if one knows how to find the correct version, read and then translate the schematics to actual physical objects with a measurement tool. That is definitely not me. I can barely measure AA batteries with a multimeter, and 50/50 chance I get the polarity right. But I'm trying to learn. The...
by Arne
Tue Nov 26, 2019 9:17 am
Forum: Hardware
Topic: 1040STf chip location help wanted
Replies: 5
Views: 1067

Re: 1040STf chip location help wanted

@tzok: don't offer fish, teach people how to do fishing :wink:
by Arne
Tue Nov 26, 2019 8:10 am
Forum: Hardware
Topic: 1040STf chip location help wanted
Replies: 5
Views: 1067

Re: 1040STf chip location help wanted

Why don't you use Brain 1.0?
Take any ST schematic and you'll see that MMU's GND are located on pins 27 and 61. GLUE's GND is on pin 35.
Now take a Multimeter/Ohmmeter and check which socket is which.
-912 is MMU, -915 is GLUE.
Easy, isn't it :?:
by Arne
Sun Nov 24, 2019 12:51 pm
Forum: Coding
Topic: Enhanced GEM and popup menu
Replies: 2
Views: 1668

Re: Enhanced GEM and popup menu

Seems I got it. I had to install an event handler to react to the cycle button event. Event_Handler(EventInit, EventHandler); static int EventInit(XEVENT* inCycleButtonEvent, int inEventMask) { (void) inEventMask; inCycleButtonEvent->ev_mflags = MU_MESAG; return MU_MESAG; } static int EventHandler(X...

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