> From: Robert Jarratt
> When the power is OK the output of the inverters is low, so the
> transistors are off, presumably allowing the signals to float high.
> When the power is not OK, the inverters are high, turning on the
> transistors and shorting the signal to ground.
Th
> My reading of the Qbus spec is that P OK and DC OK are active high. That
> diagram
They are, for a very logical reason. Remember you can wire-AND open-collector
signals
-- that is link them together so that any driver can pull the line low and the
line will
only be high if all driver transist
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson
> Sent: 25 November 2015 17:10
> To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off-
> Topic Posts
> Subject: Re: Replacing MicroVAX II PSU With a Mod
On 11/25/2015 11:01 AM, Robert Jarratt wrote:
My reading of the Qbus spec is that P OK and DC OK are
active high. That diagram tells me that both control
signals are driven the same way because the two circuits
are identical except for the timing caps. When the power
is OK the output of the in
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson
> Sent: 25 November 2015 16:37
> To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off-
> Topic Posts
> Subject: Re: Replacing MicroVAX II PSU With a Mod
II PSU With a Modern PSU
On 11/24/2015 05:52 PM, Mark Wickens wrote:
I haven't looked into this at all and I suspect it's probably quite
tricky indeed. I did look around a while back drew a blank.
I built up a Micro-VAX II system out of boards, backplanes and assorted junk. I
made my
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson
> Sent: 25 November 2015 02:05
> To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off-
> Topic Posts
> Subject: Re: Replacing MicroVAX II PSU With a Mod
On 11/24/2015 05:52 PM, Mark Wickens wrote:
4. The most difficult bit, I suspect, would be the PSU LTC signal ,
which I believe is some kind of clock. I don't know what the spec of the
signal is, but I will get a scope on a working one to see (NB don't want to
risk a working PSU on this mac
On 11/24/2015 05:52 PM, Mark Wickens wrote:
I haven't looked into this at all and I suspect it's probably quite tricky
indeed. I did look around a while back drew a blank.
I built up a Micro-VAX II system out of boards, backplanes
and assorted junk. I made my own power supply. The power
supp
4 November 2015 23:52
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: Replacing MicroVAX II PSU With a Modern PSU
>
> I haven't looked into this at all and I suspect it's probably quite tricky
> indeed. I
> did look around a while back drew a blank
I haven't looked into this at all and I suspect it's probably quite tricky
indeed. I did look around a while back drew a blank.
If you need another dead MV2 let me know, the one I collected is still sat
in the garage.
Regards,
Mark.
On 20 November 2015 at 00:00, Robert Jarratt
wrote:
> While I
11 matches
Mail list logo
