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I suspect the choice of S-Log3 (for sports coverage) is because the broadcasters want live events to look bright and colourful..... a technique pioneered by Sky Sports in the early days, " I don't care what your scope says, just open up the iris and crank up the colour. It makes it look good. ...

If you want some bedtime reading, try this topic. It’s a fairly good way to get HDMI

Mark

The ability to reply to, or to send Private Messages (PMs) is disabled for new members at first. However you can ask for full PM functionality to be enabled by using the ‘Contact us’ link (envelope icon) at the bottom of every page. This sends a message to the admin’s who will consider your request....

Is the +5V low at all the +5V/VCC and 0V/GND connections? Test on both each pair of spade terminals and on the respective main board connections. Also test on the auxiliary power connector. So right now I'm getting: AUX = 5.02v Left hand (Near PSU) spades = 4.75v Centre spades = 4.82v Right hand sp...

It’s the job of the feedback circuit to try to maintain the output voltage at exactly 5V (within a few percent). For a Beeb, this means the voltage should be at least between 4.75V and 5.25V. Most Beeb PSUs manage between 4.85V and 5.15V. If the electrolytic capacitors in the PSU are life expired, t...

This problem has been seen on some other forums.

And yes, I get it from time to time, and not always when starting new topics either...

If it annoys you, try turning off the auto-save features.

Mark

I have good enough phone signal here that I will usually swap to mobile data when my broadband goes down. But I wonder: does anyone have good enough neighbour relationships such that borrowing the neighbour's wifi would be a solution? The snag with that is, you do need your neighbours to actually h...

I used to have a PC running on a UPS. But one day the PC died. Turns out the UPS was no longer producing an output despite what it’s charge state indications were showing... So I had to dig around the back and bypass the UPS, otherwise known as unplugging cables and reconnecting them in a different ...

I think a model ‘C’ could have been a bit less expensive than that. The hardware for controlling the RAM in a ‘C’ would have been much simpler (and hence lower cost). And I suspect the pricing of the B+ was deliberately high so that the B model could still be sold. As the price of 64k bit DRAM chips...

If the semiconductor devices that are attached to the heatsinks don’t get too hot, consider fitting insulation kits to them. I prefer the thermal pads (e.g. silicone type pads), don’t forget the plastic bush for the machine screw/bolt.

Mark

anightin wrote: ↑

Sat Jan 09, 2021 8:42 pm

... so I went for one of these instead for SMD work/inspection. I found it on Amazon.co.uk:

Link or a better description please

Mark

Boydie wrote: ↑

Sat Jan 09, 2021 8:44 am

That first picture isn’t even of the machine itself - cursor key arrows are wrong.
Odd how there are loads of pictures of the packaging but none of the whole machine - always got strategically placed manuals....

The photo is from Wikipedia...

Mark

I have this headband magnifier from Amazon:
https://www.amazon.co.uk/gp/product/B07 ... UTF8&psc=1

I only use it occasionally, as I normally use a magnifier lamp.

Good even lighting also helps.

Mark

Actually if you just want an extra 32k bytes of RAM at the normal 2MHz speed, all you need is a small amount of extra circuitry controlling the ROM chip select lines and the extra RAM chips. It’s even possible to do this in an existing model B by using link S21. A hardware register (write only) is a...

Whereabouts are you in the world?

Mark

I would try IPA before anything else. If you want to try anything else, test on an unimportant part first just in case it causes problems.

Mark

Any and all ideas would be really appreciated. Can you give us some idea of your existing skills / knowledge outside of I.T. For example are you a good DIYer? Do you have good basic knowledge of electricity or electronics? Are you any good at working on mechanical equipment? In terms of work, do yo...

MartinH wrote: ↑

Fri Jan 01, 2021 7:31 pm

We're all booking a trip to Holland, via a brickyard, before any of us get level 11

There’s a brickworks near Bristol. Even their private road is paved with bricks

Who wants directions?

Mark

Not sure why the link won't imbed but hopefully you can follow the link to the pic. You need to use the Attachments tab below the text edit box to select the file/image/picture to upload to the forum. Or if your browser supports it, drag the file from a file window to the edit box. Alternatively if...

Where would the lines be drawn between new development (including minor improvements that improve functionality), changes needed due to the availability of ICs / hardware (e.g. 1772 instead of 1770), and bug fixes? We already know that with some other machines from other manufacturers, work continue...

Yes an Electron can become deaf. Checkout the many previous posts...

Mark

Classic computer sub systems sounds much better than retro bits

Mark

All the data needed to read the disk catalogue is on the first track. So if the head is already at the first track, the drive will indicate this to the disk controller chip. Hence the disk filing system will not request the drive step the head stepper motor to move the head. If while the power is of...

Hi Tom. The fact that you hear a grinding sound means that it’s very likely that a head cover has come loose and fallen and is partly obstructing the rotation of the disk. Note that the first head is on the bottom (underside) of the disk and the second head is on top. Various companies bought bare d...

We had a discussion about the 'stars' in the background that were invisible to the naked eye and were wondering if they were actually stars or camera noise. Given the cost of the lens I am hoping they are stars :D I’m no camera expert (far from it). But when working on CCTV systems, noise usually i...

Excluding magnetic media (which is better off being stored in the house), the cold temperature will not cause any damage as long as the rate of change is reasonable (that is not quick, but being in a garage, that should not be a problem) and the temperature does not go too far below -5°C. Some equip...

PNP version:
There’s no easy answer to it drawing power from the interface lines

I mean, it’s possible. But it requires various electrical buffer chips.

Mark

guesser wrote: ↑

Wed Dec 30, 2020 3:40 pm

"Then affix suitable postage and a label containing the following to the outside of the box: Mark 1024 Esq., 62 West Wallaby Street"...

Mark

Either plug in all your classic computers and leave them on so they don’t get cold and damp. Or install air conditioning (the type that can do heating as well as cooling). And insulate the walls, ceiling and the garage door. Or do all three! :mrgreen: :arrow: The legal disclaimer (inspired by Richar...

daveejhitchins wrote: ↑

Wed Dec 30, 2020 12:25 pm

PNP . . . ??

I suggested using a PNP switching arrangement so the the positive supply can be switched instead of the 0V line (which is ineffective when there are 0V connections in the signal line cable). So obviously a different schematic is needed.

Mark