Hi - New member from Australia

[thesourcerer]

I started to look into this and went blind!
But seriously:-
Those claims are 6 years old or more and there is a lot of debate and controversy there.
People saying sunlight will erase them is probably OK in places like Death Valley, but humidity and other factors are the main problem. The UV wavelength required is not significantly transmitted by glass, hence the reason for a quartz window on the chips. Even in Death Valley I think you would struggle to do it inside.
And focussing the sun on it with a glass magnifying glass will just cook the chip completely before erasing it.
When suitable UV LEDs were made is of no consequence. Do they work? I need to check that out. Certainly mercury bulbs and some (Hg) fluorescent ones do, but that is at a dangerous level for sun bed tanning lights, far exceeding the safety levels. Thinks - maybe that is what David Dickinson uses?
I will give it a try with my UV lasers and see.

[spectreman]

I will definitely get myself a UV LED and give it a go, no problems.

I have now transferred a few programs to the Organiser via the CL DOS software, works fine.
Have the WORM2 game & a flying navigation program so far.
Also tried playing with some database files in the FileMaker software.
I really need to get hold of one of the 128Kb RAMpacks so I can run larger programs on it.

[amenjet]

253nm is in the UVC range of the UV spectrum, which is the most dangerous. UVA is the least dangerous and that is still hazardous. A UVA LED would probably take quite a while to erase an EPROM, a UVC should be quite quick. You'd need to loo at the waveforms that the LEDs emit and the power and do a quick integration to work out the time each LED would take. It's a quantum process too, so you need the wavelength specified for erasure to occur, so you need UVC, a lot of UVA won't work unless there is UVA in there somewhere.

Personally, I'd put the LED in a sealed box so no UV can exit if I made one of these. I don't need to as I have UV erasers and rarely erase these days anyway. I did buy a cheap Chinese eraser a few years ago and the light leakage was so bad I think I threw it away. I definitely don't use it.

https://www.mouser.co.uk/ultraviolet_le ... zDI6kTlyY3

[Martin]

Hi Chris

Rampaks
Andrew (@amenjet) made some 'replaceable' battery 256K and 32K Rampaks. Peter (@thesourcerer) has them in his eBay store when they are 'in stock'.

I use a 32K Rampak for 'development' work they format and MAKE packs quickly. So you can try things out before committing to a Datapak. I use one of his 256K versions for developing stuff that needs a larger 'pack'. I used it to produce the large 128K version of (FindWord) for the CM/XP with its 10,000 five letter word dictionary.

Software
There is a list of all the software packs available at the bottom of the page (here) that shows if they need a 2 or 4 line display.

FindWord
Dave (@1333dave) kindly did a review (here) and suggested and provided a 'faster' search routine for the larger 10,000 word dictionary.

And finally for the XP I did the 'Christmas Stocking Filler' Adventure game (here) as something a bit different.

Sincerely
Martin

PS for others watching remember the operating system of a CM will not 'see' a Rampak

[spectreman]

Ok Martin, thanks very much for this info. I think a RamPack is the way to go for me for now.
Look forward to trying out that adventure game you posted.