Oric-1 hangs after a while

Oric-1 hangs after a while

Post by gregers » Wed, 03 Sep 2008 17:13:33


I have a Oric-1, that I hooked up today, and that seems to work fine,
for a while.

Then, when it has been turned on for a couple of minutes, it starts to
hang.
Or, the keyboard starts to hang, when I press certain keys, but not
all.

Especially when I press 2, it hangs.
The cursor is still blinking, but the keyboard stops responding.

If I take the power out, and plug it in, it works again, but only up
untill I press 2.

If I let it cool of for a couple of minutes, everything seems to work
okay again.
I guess this is an overheating issue, but I have no idea where to
start searching for errors, or what to do.

This might however be a meaningless post, since I just found out that
the power I use give out 9.6V instead of 9. So I'll check into that.

But still, if anyone have any suggestions, I'll be happy to take them,
if they've experienced a similar problem.
 
 
 

Oric-1 hangs after a while

Post by Grege » Wed, 03 Sep 2008 20:31:56


Didn't help with a more 'correct' power either. After a while the
computer starts *** when I press certain keys.
Seems very odd.

 
 
 

Oric-1 hangs after a while

Post by Grege » Thu, 04 Sep 2008 01:04:23

After some more investigation I have found out this;
When it has been off for a while, it works without problems for a
while.

I wrote a neverending loop in basic, and started it.
It runs without any problem.
When I press certain keys[1], the keyboard hangs, but the program
keeps on running.
If I press the reset button, the keyboard works again, untill I press
one of said keys.
Could this be the keyboard controller over heating? Is there anything
I can swap out?


[1]
2 q s x DOWN ARROW \ ]
 
 
 

Oric-1 hangs after a while

Post by Steve Mars » Thu, 04 Sep 2008 07:49:22


"Greger" < XXXX@XXXXX.COM > wrote

Sounds typical of component failure when the component heats up. It can be
tricky finding what is the problem. Check connections on anything socketted.
It could be faulty 6522.

See if anything in the service manual helps - available on my website
www.48katmos.freeuk.com

Steve M
 
 
 

Oric-1 hangs after a while

Post by Andre Majo » Thu, 04 Sep 2008 17:30:11


Oric-1, eh ? Translated from _L'Oric nu_ :

#F535: Write X into PSG 8912 register A

The V1.0 ROM version of this routine takes too much time to
write the value after selecting the register which makes it
very picky with 8912 chips and how hot they run. The version
in the V1.1 ROM is more reliable because it is faster. THIS IS
WHY SO MANY ORIC-1 WITH PERFECTLY GOOD HARDWARE WERE RETURNED
FOR SERVICE.
>> [1] >> 2 q s x DOWN ARROW \ ]

All those keys are on the same column so it might be an
intermittent connection (re-seat the keyboard connector). The
4051 on the keyboard PCB is probably good otherwise all columns
would be affected.

--
AndrMajore< http://www.yqcomputer.com/ ~amajore>/>
"Je regrette le Concorde. Au moins il vous amenait directement l'hel." -- Cyrano
 
 
 

Oric-1 hangs after a while

Post by Grege » Thu, 04 Sep 2008 20:13:07


A nice old Oric-1, yes.
>> >> #F535: Write X into PSG 8912 register A> >> > The V1.0 ROM version of this routine takes too much time t>
> write the value after selecting the register which makes >t
> very picky with 8912 chips and how hot they run. The vers>on
> in the V1.1 ROM is more reliable because it is faster. THI> IS
> WHY SO MANY ORIC-1 WITH PERFECTLY GOOD HARDWARE WERE RET>RNED
> FOR SE>VICE.
>

Is it possible to upgrade to the V1.1ROM?
Or will it be reasonable to check the connections on the 8912?
Or even replace it with a new one? I see the 8912-chips aren't that
expensive to get, so I could order 3 or 4.
 
 
 

Oric-1 hangs after a while

Post by Andre Majo » Fri, 05 Sep 2008 00:41:15


>> Oric-1, eh ? Translated from _L'Oric nu_ : >> >> A nice old Oric-1, yes. >> >>> >>> #F535: Write X into PSG 8912 register A>>>>>>>> The V1.0 ROM version of this routine takes too much time t>> >> write the value after selecting the register which makes >>
>> very picky with 8912 chips and how hot they run. The vers>>n
>> in the V1.1 ROM is more reliable because it is faster. THI>>IS
>> WHY SO MANY ORIC-1 WITH PERFECTLY GOOD HARDWARE WERE RET>>NED
>> FOR SE>VI>E.
>
> Is it possible to upgrade to the V1.1ROM?

If you have one (or a 27128 and an EPROM programmer), >es.

> Or will it be reasonable to check the connections on the>8912?
> Or even replace it with a new one? I see the 8912-chips aren'> that
> expensive to get, so I could order 3 or 4.

Yes, although it's not socketed so you'll have to desolder a
28-pin chip first, which might not be easy if you don't have the
equipment and the experience.

But first, I'd try re-seating the keyboard PCB. You could also
try putting a heat sink on the 8912 :

http://www.yqcomputer.com/
http://www.yqcomputer.com/

Or whatever piece of aluminium foil you have handy, 0.5 to 1.5 mm
thick, tacked to the top of the body with thermal grease. Check
that it fits inside the case and doesn't come off the chip and
short something else on the PCB !

--
Andrlt;Majorel http://www.yqcomputer.com/ ~>majorel/>
"Je regrette le Concorde. Au moins il vous amenait directement l'hel." -- Cyrano
 
 
 

Oric-1 hangs after a while

Post by Steve Mars » Sun, 07 Sep 2008 07:09:28


"Andre Majorel" < XXXX@XXXXX.COM > wrote


Is this what the amendments in the service manual fix? Service bulletin 1
seems to describe it.
If so a capacitor and a resistor will fix things.

Steve M
 
 
 

Oric-1 hangs after a while

Post by Andre Majo » Sun, 07 Sep 2008 20:16:16


What this modification does is force the 8912's BDIR input to
return to ground after a little while, even if the 6522 holds it
high. I'm not sure how this relates to the write-up in _L'Oric nu_ but the symptoms certainly match !

--
AndrMajore< http://www.yqcomputer.com/ ~amajore>/>
"Je regrette le Concorde. Au moins il vous amenait directement l'hel." -- Cyrano
 
 
 

Oric-1 hangs after a while

Post by mjb » Tue, 09 Sep 2008 07:11:22

In article < XXXX@XXXXX.COM >,


I was just about to mention that :) -- I think that's the hardware fix
for the software error pointed out earlier in the thread.

A V1.1 ROM will also fix it, by virtue of having the routing written
properly. This will also avoid soldering/desoldering/track cutting.
--
--------------------------------------+------------------------------------
Mike Brown: mjb[at]pootle.demon.co.uk | http://www.yqcomputer.com/