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Re: Forgottenmyname - Progress - Part 2
Posted: 28 Jun 2019 20:03
by PhilC
I've just removed the 4 chips and am putting sockets in but will check those after
Re: Forgottenmyname - Progress - Part 2
Posted: 28 Jun 2019 20:39
by PhilC
exxos wrote: 28 Jun 2019 19:41
PhilC wrote: 28 Jun 2019 19:28
yes they are buti'm wondering if one has died. typical I soldered these direct to the board
Saying that, both would have had to die to block the whole databus out..
Have you metered the enable lines from the MMU to the buffers ? pins 30,9,25 on the MMU..
You sir, are a genius as usual :-)
A blob of hot snot had given me a dry join on Wdat
Re: Forgottenmyname - Progress - Part 2
Posted: 28 Jun 2019 20:43
by exxos
PhilC wrote: 28 Jun 2019 20:39
You sir, are a genius as usual :-)
A blob of hot snot had given me a dry join on Wdat
Are you booting now then ?
Re: Forgottenmyname - Progress - Part 2
Posted: 28 Jun 2019 20:46
by PhilC
No, got 1 bit of ram with a fault. will track it down with the scope
Re: Forgottenmyname - Progress - Part 2
Posted: 28 Jun 2019 23:31
by PhilC
Fixed a couple more dodgy connections but still got 1 bit failing, so need to track that down with the meter / scope over the weekend but so far it's looking promising for my second Alpha board.
Re: Forgottenmyname - Progress - Part 2
Posted: 28 Jun 2019 23:33
by exxos
If you know which bit then you can probably trace it to the ram and buffers.
Re: Forgottenmyname - Progress - Part 2
Posted: 28 Jun 2019 23:50
by PhilC
Yeah it's just associating that bit with the falcon ram board that I've not worked out as yet.
I did notice that pin 60 one of the Mad lines IIRC on the MMU has a very poor signal, goes to R64 and then to the Ram but it's got that with or without the Ram board attached.
Learning lots doing this.
Re: Forgottenmyname - Progress - Part 2
Posted: 29 Jun 2019 16:56
by PhilC
so this is the latest mem failure using the diag cart as I prefer the feedback it gives for memory diagnosis.
latestmemfailure.PNG
so I know that the right 16 zeros means D0-D15 from fixing my 32 chip STFMs, can someone verify for me what the left mean please.
I know it's byte 1, is this indicating A1 has a failure? or Mdata1? I did have a few loose connections which I sorted out, for instance pin 60 on the MMU was bad in the socket and wasn't making contact with the ram but thats now fixed.
Re: Forgottenmyname - Progress - Part 2
Posted: 29 Jun 2019 17:10
by Icky
PhilC wrote: 29 Jun 2019 16:56
so this is the latest mem failure using the diag cart as I prefer the feedback it gives for memory diagnosis.
latestmemfailure.PNG
so I know that the right 16 zeros means D0-D15 from fixing my 32 chip STFMs, can someone verify for me what the left mean please.
I know it's byte 1, is this indicating A1 has a failure? or Mdata1? I did have a few loose connections which I sorted out, for instance pin 60 on the MMU was bad in the socket and wasn't making contact with the ram but thats now fixed.
I thought the left side is the address lines. I could be mistaken though.
Re: Forgottenmyname - Progress - Part 2
Posted: 29 Jun 2019 17:12
by exxos
They both look 16 bit, but maybe diagrom assumes 030 CPU and does 32bit access... but even that wouldn't';t make sense as the same bit on the left bank would also be stuck...
Maybe ping TF and ask him what it means...