Oric Atmos resets after a few seconds ... when not grounded

If you want to ask questions about how the machine works, peculiar details, the differences between models, here it is !
How to program the oric hardware (VIA, FDC, ...) is also welcome.
Godzil
Squad Leader
Posts: 755
Joined: Sat May 21, 2011 7:21 pm
Location: Between UK and France
Contact:

Re: Oric Atmos resets after a few seconds ... when not groun

Post by Godzil » Tue Mar 03, 2015 11:01 am

Chema: no this is not stupid, as heat make copper contract or expand, a micro cut could do a lot of things.

As the most hot point on the Oric mother board is around the 7905 I would search there first.

Also the wire mess on your oric bother me, I hadn't had time to check everything, but there is still one wire that I can't explain right now.

By the way, if you have an EPROM programmer, maybe you have some empty compatible eprom, there are some test rom for the oric, you could try to burn one, and test your oric with it to see, it if still reset, it would mean that the ROM is not a problem and there is a nasty hardware problem, but if the reboot is because of a faulty chip other than the ULA or the 6502, the test ROM could help to find the culprit.

For a possible microcut, I thing you could do, is to take apart your oric, unplug the keyboard, so leaving only the mother board, plug the screen, the power, and genlty, really gently, bend the board, if there is a microcut on a track it may bring out.

TomPhobos
2nd Star Corporal
Posts: 21
Joined: Thu Feb 26, 2015 9:42 pm

Re: Oric Atmos resets after a few seconds ... when not groun

Post by TomPhobos » Tue Mar 03, 2015 11:48 pm

Hmm, a micro cut could really be. I measured some main tracks, but i really should measure the voltages and some more lines. And yes, the wire mess is also really strange. Maybe a wrong mod, a broken cable or noise on the wires causes the problems.
Yes, i have an EPROM programmer. But i don't know if a single EPROM would work, because my Atmos has 2 EPROMs. Maybe here i also need a LO and a HI ROM.

User avatar
kenneth
Flying Officer
Posts: 179
Joined: Fri Nov 26, 2010 9:11 pm
Location: France PdD
Contact:

Re: Oric Atmos resets after a few seconds ... when not groun

Post by kenneth » Sun Apr 05, 2015 11:29 am

I think that a ghost signal appears in the RESET pin of the 6502A. IT happens easily with a floating voltage

TomPhobos
2nd Star Corporal
Posts: 21
Joined: Thu Feb 26, 2015 9:42 pm

Re: Oric Atmos resets after a few seconds ... when not groun

Post by TomPhobos » Mon Apr 20, 2015 3:43 pm

Hmm, that could be ... but the question is, what causes this problem and how can i solve it?
Actually i haven't done much in the last weeks with my Oric. In june i'm at a computer meeting. One of the visitors has an oscilloscope. He is great in repairing computers, so i hope that he will find (and fix) the problem :)

Godzil
Squad Leader
Posts: 755
Joined: Sat May 21, 2011 7:21 pm
Location: Between UK and France
Contact:

Re: Oric Atmos resets after a few seconds ... when not groun

Post by Godzil » Mon Apr 20, 2015 4:01 pm

Don't forget to dump the ROM of your german keyboard oric :)

TomPhobos
2nd Star Corporal
Posts: 21
Joined: Thu Feb 26, 2015 9:42 pm

Re: Oric Atmos resets after a few seconds ... when not groun

Post by TomPhobos » Mon Apr 20, 2015 4:06 pm

Oops. yes. you are right :oops:
Well, i haven't looked at my Oric for a long time ( i know, what a shame ;) ) so i totally forgot it. I hope i'll find the PSU of my "Eprom burner Win98-Laptop" so i can dump the ROMs (2 EPROMs) next weekend.

Godzil
Squad Leader
Posts: 755
Joined: Sat May 21, 2011 7:21 pm
Location: Between UK and France
Contact:

Re: Oric Atmos resets after a few seconds ... when not groun

Post by Godzil » Mon Apr 20, 2015 4:09 pm

Thanks :)

User avatar
Symoon
Archivist
Posts: 1152
Joined: Sat Jan 14, 2006 12:44 am
Location: Paris, France
Contact:

Re: Oric Atmos resets after a few seconds ... when not groun

Post by Symoon » Mon Apr 20, 2015 7:01 pm

As an alternative, CSAVE"ROMGER",A#C000,E#FFFF would do it!
Mmmmh, that is, of course, if you can keep the Oric running long enough without rebooting.

Godzil
Squad Leader
Posts: 755
Joined: Sat May 21, 2011 7:21 pm
Location: Between UK and France
Contact:

Re: Oric Atmos resets after a few seconds ... when not groun

Post by Godzil » Tue Apr 21, 2015 9:49 am

And you have a tape cable :D

But that a solution :D

User avatar
Silicebit.
Flying Officer
Posts: 231
Joined: Thu Jan 12, 2006 10:18 pm
Location: Madrid, Spain
Contact:

Re: Oric Atmos resets after a few seconds ... when not grounded

Post by Silicebit. » Mon Jun 12, 2017 7:32 pm

TomPhobos wrote:
Thu Feb 26, 2015 10:30 pm
Hi,

as promised in my welcome post here is the problem that i have with my Oric Atmos.

It's a german Atmos that was sold to me as new old stock. So i bought it directly. When i got it first i measured the power adapter to check if the output voltage is too high. But it wasn't too high, nothing came out of it. OK, i checked out the parameters of the power supply and used a 9V universal one.
The Atmos started, but only a cursor appeared in the upper left corner. So i opened the computer and noticed that i wasn't the first one who did it. The warranty sticker was lift up before. Ok, so i finished opening it and here's the mainboard:

Image

As you can see it's an issue 4 mainboard. It has 2 ROMs:

Image

I pressed them i their sockets and luckily the computer started ... but only for a few seconds. Then it resets and hangs.
When i checked the mainboard i noticed that there was some work on it before: ...
Mmmm strange, an Atmos with two EPROMS, It will not work with your controller.
Oric user since 1984. YouTube

TomPhobos
2nd Star Corporal
Posts: 21
Joined: Thu Feb 26, 2015 9:42 pm

Re: Oric Atmos resets after a few seconds ... when not grounded

Post by TomPhobos » Tue Jun 13, 2017 8:27 am

Hmm, ok, no problem. Then i will use the controller with my Oric-1 and maybe sometimes i'll get another Atmos :-)
The dump of the EPROMs will come this weekend. The Willem programmer is ready, the Win98-computer too :)

User avatar
Silicebit.
Flying Officer
Posts: 231
Joined: Thu Jan 12, 2006 10:18 pm
Location: Madrid, Spain
Contact:

Re: Oric Atmos resets after a few seconds ... when not grounded

Post by Silicebit. » Tue Jun 13, 2017 9:13 am

In this thread you can see an Oric with ROM: http://forum.defence-force.org/viewtopi ... 733#p15730

To use Microdisc controller with EPROM or EEPROM you can use this invention.http://retrowiki.es/viewtopic.php?f=7&t=200031702
Oric user since 1984. YouTube

User avatar
Symoon
Archivist
Posts: 1152
Joined: Sat Jan 14, 2006 12:44 am
Location: Paris, France
Contact:

Re: Oric Atmos resets after a few seconds ... when not grounded

Post by Symoon » Tue Jun 13, 2017 1:55 pm

That will be interesting, because we had a German Orician at the French meeting last weekend (Michael), he had an Atmos with German keyboard and he let me dump the German ROM. There it is; we'll see if there's a difference between the two ;)
rom_allemande_Michael.zip
(12.67 KiB) Downloaded 26 times

User avatar
iss
Flight Lieutenant
Posts: 478
Joined: Sat Apr 03, 2010 5:43 pm
Location: Bulgaria
Contact:

Re: Oric Atmos resets after a few seconds ... when not grounded

Post by iss » Tue Jun 13, 2017 5:04 pm

Thanks, Symoon!
This is very interesting rom. Main differences compared to 1.1 are:
- version is 1.3 A
- German characters
- all error messages are lower case
- no key clicks
- print char and read key are used trough vectors in page 2 instead of ROM calls
- different CSAVE/CLOAD routines
rom13a.jpg
rom13a.jpg (5.03 KiB) Viewed 639 times
german.jpg
german.jpg (27.15 KiB) Viewed 639 times
It will be interesting to see TomPhobos dumps too.

User avatar
Symoon
Archivist
Posts: 1152
Joined: Sat Jan 14, 2006 12:44 am
Location: Paris, France
Contact:

Re: Oric Atmos resets after a few seconds ... when not grounded

Post by Symoon » Tue Jun 13, 2017 6:33 pm

Long ago, Fabrice had a "DE" ROM, and he said it was exactly the same than then ROM 1.1b except:
- Y and Z key exchanged on the keyboard mapping (and on the keyboard!)
- 3 chars redefined: shifted [ and ] display ä and ü instead of { and }, and the key - shifted displays ö instead of £.

So I guess this 1.3 A is heavily modified !
I found back the ROM, it was provided by Jean from the CEO and dumped by Thierry
rom_DE_Thierry-Jean.zip
(12.63 KiB) Downloaded 20 times

Post Reply

Who is online

Users browsing this forum: No registered users and 3 guests