> From: Tony Duell
> A short in FET Q15 on the bias/interface board in the PSU could do it.
> The gate of that FET is driven from an LM339 comparator the -ve supply
> of which is -15V.
Ah; I hadn't even looked at the P/S prints.
(Like I said, I'm really weak on analog: for digita
On 2022-Mar-31, at 12:36 AM, Noel Chiappa via cctalk wrote:
>> From: Tony Duell
>
>> A short in FET Q15 on the bias/interface board in the PSU could do it.
>> The gate of that FET is driven from an LM339 comparator the -ve supply
>> of which is -15V.
>
> Ah; I hadn't even looked at the P/S prints
I made some interesting discoveries this evening. See below.
> -Original Message-
> From: cctalk On Behalf Of Brent Hilpert
via
> cctalk
> Sent: 31 March 2022 21:03
> To: General Discussion: On-Topic and Off-Topic Posts
>
> Subject: Re: PDP 11/24 - A Step Backwards
>
> On 2022-Mar-31, a
On 3/29/22 10:51, Brielle via cctalk wrote:
Yes, saw an article that said he was fine. Not sure if there’s been any
updates since that article though given how things have escalated…
I exchanged email with Dmitry Cherepanov this morning. He is
understandably heartbroken, but he and his fa
On 2022-Mar-31, at 2:14 PM, Rob Jarratt wrote:
>> Those three comparators in the H777 are looking at a time-delay ramp
>
> Is that a typo? This is the H7140 not the H777.
Groan.
When this thread came up I went looking for the 11/24 schematic. I found the
document I linked earlier for the 11/24
> From: Brent Hilpert
> So apparently I've been looking at the wrong +5V supply (H777) because
> the rest of you are indeed looking at a different +5 supply (H7140),
> both of which are in that same 11/24 pdf document
That's because the H777 is the P/S for the BA11-L 5-1/4" box, a
On 2022-Mar-31, at 4:12 PM, Noel Chiappa wrote:
>> From: Brent Hilpert
>
>> So apparently I've been looking at the wrong +5V supply (H777) because
>> the rest of you are indeed looking at a different +5 supply (H7140),
>> both of which are in that same 11/24 pdf document
>
> That's because the H7
> From: Brent Hilpert
> DCLO & ACLO behave as power-on-reset signals to the system.
Minor nit: actually, I think it's DCLO which performs that function in a lot
of places; see e.g. the latches on pg. K2 (pg. 153 of the PDF) and K7. (INIT,
usually in buffered form, is used more widely for
On Fri, Apr 1, 2022 at 12:13 AM Noel Chiappa via cctalk
wrote:
> > I really wish when people are asking for assistance or talking about a
> > schematic or circuit they would include a link/reference to exactly
> > what they are looking at
>
> But everone probably _was_ looking at the
Hey all, found this on eBay:
https://www.ebay.com/itm/Corning-Glass-memory-/125087612899
I can't find any info on it - was it some kind of delay-line or magnetic
laminate stack?
Interesting!
On 2022-Mar-31, at 8:05 PM, Anders Nelson via cctech wrote:
> Hey all, found this on eBay:
>
> https://www.ebay.com/itm/Corning-Glass-memory-/125087612899
>
> I can't find any info on it - was it some kind of delay-line or magnetic
> laminate stack?
>
> Interesting!
Very interesting - there w
Here is some pretty good information.
https://archive.org/details/TNM_Glass_computer_memories_-_Corning_Electronics_20171206_0185
Mark
-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Brent Hilpert
via cctalk
Sent: Thursday, March 31, 2022 11:53 PM
To:
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