Oric Diag failing on Test 9 (Cassette Output/Relay/Amp/Speaker)

[john]

I've got a Oric Atmos that I've built using one of the clone boards.

As far as I can see everything is working 100% but decided to run it through it's paces with the Oric Diag and loopback connectors.

Try as I might the test always fails on:
Test 9: 6522 VIA Port B7/B6/Cassette Output/Relay/Amp/Speaker
I can hear the speaker beeping but it beeps about 10-15 times and then the test fails.

I'm pretty much out of ideas and not sure if I believe the failed test.

First off, has anyone run this test with the loopbacks and does it pass?

I've compared the clone board to the Oric schematics in case there is a design fault, but it's identical to the schematics.
Checked the 6522 and also replaced with a known good chip.
Relay is working - I've checked it in a separate circuit and it's switching.
LM358 amplifier is working. There is not really much else that can go wrong.

I've checked with a scope on pin 17 and 18 on the 6522 and seeing a decent square wave. The square wave looks very much the same on both pins.

As I'm seeing a waveform on Pin 18 it pretty much rules out issues with the LM358, transistor, relay etc.

Screenshot from 2024-07-29 22-29-32.png

pic_89_5.jpg

Any clues as to why this is failing if everything looks ok. Unless the waveforms are not supposed to look like that.

[Sodiumlightbaby]

Sounds like a head sratcher. All I can contribute is I have run the diag ROM w/cassette loop-back and it passed.

[Dbug]

First off, has anyone run this test with the loopbacks and does it pass?

Well, I ran it on a well functioning Atmos when I received the diagnostic card, and it did work.
That's all I can say, sorry.

[kenneth]

If the ROM chip inside the computer is an UVProm one, you must disconnect it.

[Vyper68]

I built my own loopback connectors and diagnostic boards and have been able to pass all the tests on several computers.
I remember being confused by the Beeping and fitting the keyboard loopback later in the sequence. I’ll have to have a think.

[Vyper68]

So reading the instructions again you have to press the NMI button when you hear the beeping to move to the next test. If you leave it alone it will time out and fail the test. Which is what I was falling foul of back when I first used it.
So soon as you can hear the beeping press the NMI and see what happens?

[john]

So reading the instructions again you have to press the NMI button when you hear the beeping to move to the next test. If you leave it alone it will time out and fail the test.

Finally got time to relook at this.

Lol. Looks like I need to learn to read.

All working. Thanks for the help.

[Sodiumlightbaby]

Ha ha, that's great! A fix I can relate to. Congrats on getting a working new machine

[Vyper68]

Great to hear you have a fully working Oric.