Issue with M8190 CPU board

[pjrebordao]

I have an M8190-AE CPU board complete with a DCJ11-AC processor. The board is on a BA213 backplane.
Power is supplied by an ATX PS, managed through a front panel design taken from here https://avitech.com.au/?page_id=1657
Every signal from it was checked before the final test.

When I first powered it, the green Led on the CPU came on together with the 6 red Leds and it stayed that way.

According to documentation, the 6 red Leds mean an error code of octal 77.
This could mean:

• Halt condition (NOT)
• Bad Power supply (NOT)
• Terminator is faulty
• Grant card not installed

I'm more inclined to the last 2, despite there being many other points of possible failure.

In particular, do I need a grant card installed ? The CPU board sits on slot 1 and there's no other board present.

PS - the processor is the AC version (15Mhz) while the board has a 18Mhz crystal, but I don't imagine that to be the reason...

Thank you-

 

[Terri Kennedy]

I have an M8190-AE CPU board complete with a DCJ11-AC processor. The board is on a BA213 backplane.
Power is supplied by an ATX PS, managed through a front panel design taken from here https://avitech.com.au/?page_id=1657
Every signal from it was checked before the final test.

When I first powered it, the green Led on the CPU came on together with the 6 red Leds and it stayed that way.

PS - the processor is the AC version (15Mhz) while the board has a 18Mhz crystal, but I don't imagine that to be the reason...

I don't think there's any on-board RAM on an 8190 board. I also don't remember if the console will enter ODT if there is no RAM. Do you have the I/O bulkhead, baud rate selector switch and console connector? The I/O bulkhead just replicates the status LEDs as a pair of octal digits, so that part isn't important.

While there is cache on the 8190, I think the board comes up with it disabled until it is tested, and to test it you need working RAM. This is different than the 11/70, where the cache comes up enabled and can fool you into thinking the system has working RAM when it doesn't.

 

[daver2]

The M8190 should enter ODT Ok (and run ODT) with no RAM (as long as it is configured to). This is how I have brought up numerous systems in the past. Ok, you can't actually do much with just a CPU board in ODT, but it is a start!

You do not require a grant card if there are no other cards in the system. You require a grant card where you have (for example) a missing card in a half-slot.

If the missing card forms part of (what should be) a continuous chain from the cards to the CPU, you have to install a grant card. Since you only have a CPU, you don't need one.

With no RAM you can only really enter ODT. To enter ODT you need to have configured this mode on the CPU board or manually pressed the HALT button. Hence you should really be in HALT mode...

Octal 77 is also the 'default' code on a power-up with a dead CPU, but let's not go there yet.

How have you wired up the serial port is my next question. If we want the CPU to enter ODT, we will need a terminal to see the '@'.

Dave

 

[Hunta]

the processor is the AC version (15Mhz) while the board has a 18Mhz crystal, but I don't imagine that to be the reason

Most likely - this is the reason.
Replace the quartz with 15 MHz or the processor with DCJ11-AA or DCJ11-AE
From my experience - only selective DCJ11-AE processors can work at an increased frequency and the symptom of inoperability is the processor not starting (code 77)

 

[pjrebordao]

I'll change the crystal next week and try again. Fingers crossed...