Hi All,
Just when I thought it was save to screw the roof on this Master 128, I acquired an Econet card.
Inserted it, added the ANFS 4.25 ROM and put it all together.
When I connected it to the Econet Bridge, the Master booted only as far as the "Acorn MOS" prompt.
If I remove either the cable, the ROM or the Econet card, or any combination thereof, it boots fine (apparently).
Searching through the various fora, I forgot to switch off the Master.
After about 60 seconds of Acorn MOS hanging, a beep and then:
Acorn MOS
Acorn 1770 DFS
Basic
>
What appears to be a clean boot after a one minutes pause.
*NET produces a new prompt.
*I AM MADDOG
Hangs with a flashing cursor until reset/reboot. Which then hangs at:
Acorn MOS
For another minute.
According to the service manual
Section 7.17 (econet)
'Follow the Econet board circuit diagram in the Appendix'.
There is no Econet board circuit diagram in the appendix, at least, in the version of the service manual I have.
In that same section, item 3 suggests:
'Check that NMI on the CPU pin 6 IC14 (TP 3) is not being held low'.
It IS low everywhere I have tested where the diagram says it should be there.
I have another Master with Econet fitted. Cable, Econet card, ROM, have all been interchanged and tested working.
It is a problem with 'this' machine.
Any ideas where to look please?
Should NMI be doing something? It remains low with the Econet parts present or absent.
If so, is it IC 14 which asserts it?
The consistent pattern should be an indicator, but not knowing the sequence of events the Master goes through to boot, I can't think where to start looking.
I will maybe pull and socket IC14 G65SC12 with some trepidation but if anybody could narrow my search I would be most grateful.
P.S. Not tested the Disk drive yet so that could open a new can.....
Best Regards,
Stewart.
Just when I thought it was save to screw the roof on this Master 128, I acquired an Econet card.
Inserted it, added the ANFS 4.25 ROM and put it all together.
When I connected it to the Econet Bridge, the Master booted only as far as the "Acorn MOS" prompt.
If I remove either the cable, the ROM or the Econet card, or any combination thereof, it boots fine (apparently).
Searching through the various fora, I forgot to switch off the Master.
After about 60 seconds of Acorn MOS hanging, a beep and then:
Acorn MOS
Acorn 1770 DFS
Basic
>
What appears to be a clean boot after a one minutes pause.
*NET produces a new prompt.
*I AM MADDOG
Hangs with a flashing cursor until reset/reboot. Which then hangs at:
Acorn MOS
For another minute.
According to the service manual
Section 7.17 (econet)
'Follow the Econet board circuit diagram in the Appendix'.
There is no Econet board circuit diagram in the appendix, at least, in the version of the service manual I have.
In that same section, item 3 suggests:
'Check that NMI on the CPU pin 6 IC14 (TP 3) is not being held low'.
It IS low everywhere I have tested where the diagram says it should be there.
I have another Master with Econet fitted. Cable, Econet card, ROM, have all been interchanged and tested working.
It is a problem with 'this' machine.
Any ideas where to look please?
Should NMI be doing something? It remains low with the Econet parts present or absent.
If so, is it IC 14 which asserts it?
The consistent pattern should be an indicator, but not knowing the sequence of events the Master goes through to boot, I can't think where to start looking.
I will maybe pull and socket IC14 G65SC12 with some trepidation but if anybody could narrow my search I would be most grateful.
P.S. Not tested the Disk drive yet so that could open a new can.....
Best Regards,
Stewart.
Statistics: Posted by Maddog Bailey — Tue Feb 18, 2025 12:38 am