Most liked posts in thread: Voltages wondering about the Oric-1 - Just to be sure before I toast it!

So, how the story of this unfortunate Oric goes on? I'm curious to see if it can go back to work, although I'm pretty sure that Klyde will succeed in the end!

 

Sorry, BTW I've been away for a while, and you didn't hear that much from me. After 2 months in Rome to help my parents after the incident, I had lots of issues with work, culminating in a minor crash last week at the datacentre that I manage on my own. Hardware failures so it took a lot of work and time to restore everything in a working condition. I'm still on it, TBH. Ok, enough of me, let's go back to retrocomputing.

 

Hey, Dazza.

Sincerely, we all hope you are OK - another sad story of folks battling to help others and then coming a cropper themselves.

Treasure all we have that means so much to us, eg family, loved ones, loyal friends and of course... our faithful retro treasures.

Do take extra care and keep the faith, my friend.

How's Klyde/Manu getting on? Any progress on this Oric-1 and how is Rich - ready for a catch up when you are, buddy, as we are currently working from home self-isolating so have a bit more time for a natter when you're free, mate.

 

If you’re too busy at the moment @Klyde I have plenty of spare time these days and I have all the spares.

 

I must have lost much of the Oric stories here on AOC, especially Andy's. For example, what's the state of the art about Orics running at the Bazza towers? Any new entry? Telestrat or Oric modern/old disk drives? Where the famous lot of 8 French Orics went to? All fixed and sold? Any other Oric adventures with pretty stories in them to tell? I've got one about a lost and then found SwinSID for a broken C64. I may start a new thread called hardware stories.

 

A quick note about the Oric.

First I realised that the SCART cable I built was faulty, I could never display a picture with it. Once fixed I could have a picture: A scrambled screen with odd characters, generaly the sign of a faulty RAM.

I then desoldered and tested the RAM chips, they are ALL faulty!! The ULA was not the culprit finaly...
Next step: replacing the RAM chips.

 

Ah yes, we spent a good time in Duxford! Hope we can do it again!

 

Keep going, Klyde.

The end justifies the means...



OR



= pure working Oric heaven.

 

Brilliant work, Manu.

If anyone can sort these pesky Oric problems - it's you n Richie!

I will look into that buzzing sound issue you have it.

Does it ring any bells with you, Rich?

Have a good old sound riot with your predefined sounds, Manu.

I will try and find you a listing that makes them sound like a synth orchestra... or maybe not!

 

And another 8-bit computer is now saved from oblivion. Nice, nice work, Manu.
PhantasmagORIC result!

 

You do get some background noise from the speaker in use, you might not be used to it. The Oric is quite a noisy system compared to the Amstrad or Atari. You could maybe try to replace the old ceramic decoupling capacitors for modern Wima ones and see if that helps.
You need to do the service update to protect your PSG as the v1.0 ROM destroys it over time. You can also replace with the v1.1 ROM as that fixed the bug.
I’ll be ordering your SCART lead in a couple of days Manu.

 

Hi guys,I have received and installed the new 7905, and now I have the correct +5V all around the board.

But it's still a no go.

I have noticed with my scope that some address lines seems ok, but also that :

• The CPU doesn't resets itself, although the reset line is tested ok,
• I have no bus activity (address lines always high and data lines always low) between the CPU, the VIA, the sound chip and the ULA,
• I have some good looking address bus activity between the ULA and the RAM, through IC8 and IC20, but no data I/O on the RAM,
• I have a good looking 64µs video sync signal from the ULA but no R, G & B signal (always low).

I tried to read the ROM with my programmer, it is not listed as compatible but the closest I could find was the HN27128AP, and it says "Read error".

Any idea of what I should test next?

 

@Klyde Hey mate, can you test the resistance between the 5v and ground on some of the logic circuits on the PCB and report back.
Have you got a copy of the test ROM?

 

@Vyper68 Yes, good idea! I will.

 

Brilliant, Rich.
Top man for all that assistance.
I hear my pal Johnny is as happy as a pig in mud now with his working Atmos and I have been invited down for an outside meet-up for tea n scones when he will be happy to pose for a photoshoot for the lads to show his lurve for Oric...thread to follow!
(Yes, he is categORICally mad).

 

I forgot to mention that I found various clocks are present accros the board , but I'll recheck thoroughly.

Many thanks for your help.

 

Hi Rich, the 12Mhz and 1Mhz clocks are present and have the appropriate shape, like the ones shown in the service manual, excepted for IC9 pin 6 (no clock) where I find a constant +3.6V. I have no IC10 installed (27128 chip ROM version).

Are you sure about IC9? According to the schematics, pin 6 seems to be an address line...

 

Sorry I made a mistake it should be pin 6 IC21 to pin 22 IC9

 

I have a good looking 1Mhz clock on IC9 pin 22.

It is a mystery. I continue to investigate... Next step will be to swap the chips I should receive in a couple of days now.

Many thanks for helping me mate!

 

As ever, brilliant advice there from Richie - massively appreciated and all being well, Manu will be able to get his Oric-1 flying in the end. Good luck, Manu!

 

I have received your PCBs yesterday Richie, they are really neat, and will be very handy! thank you mate!

I also have received the RAM chips, so I can test them.

But Andy what you feared arrived, the ULA was lost by the courier... IFAIK (abbreviation, LOL!) it was delivered to someone else, I don't know where... I have to investigate and ask for a refund.

Richie, before sending me one, let me replace the RAM chips to see where it drives me.

 

Aw, Manu, I'm so sorry to hear.
Let's hope the RAM chips may be the solution and if not - well, a new ULA can only help / be useful in the future etc,

 

Good to hear that there is some progress to your Oric story, Manu.

Hey, we spent the weekend near Cambridge with the friends we were with the last time we met up, buddy,at Duxford. Many aircraft flew over their house over the weekend incl a Spitfire, Hurricane and Dakota and so I thought of you and your pals from last time, mon ami.

Dazza asked about some Orics which arrived here courtesy of a distant sale that you helped negotiate. I wish I had still had a few as they made a good price back then but Atmoses are now making crazy prices - some going for over £200 for the bare computer so you can imagine that a boxed example with some software and accessories could push £300?
(This is what some people are asking for on Feebay).

Basically, they have gone now, Dazza and they went towards financing the wedding so they were sold for a worthy cause else I would still be single and living out of a phone booth...(!)


ABOVE: Baz's cave before Bev let him in to her abode.

 

We certainly did, Manu.

I hope in the future that we manage to get a good few of us together as it would make for a super retro rendezvous.

Sending my very best to you all, Manu and hope life is treating you well.

 

Hi Manu,
Did you burn a 16K EPROM with a v1.1 BASIC on the off chance the Rom is damaged?