Re: Clearing EPROMs: How much time to lay in the sun?

From: Gabriele Bozzi (
Date: 2006-07-16 18:28:20

Oh dear...

Once I tried, really, but one week later I went down to town to buy  
my eprom eraser!!
Eproms are one of the most fabled ant FUDded item of electronics, I  
found a no-nonsense guide to Eproms at this address:

It is really well written and, as far as my knowledge on the matter  
goes, fairly accurate.

Anyway your answer is: depends on the weather, altitude, latitude,  
season and humidity, just some short calculations (which do not  
pretend to be assertive, do not flame me):

- A common eprom eraser like mine takes 5 minutes to bring all 1s to  

- A mid-summer Northern emisphere location at Sea level, 60%  
humidity, sunny exposure (75% of total sunlight):  ~ 15 days

But you could be particularly lucky and live on top of the Matterhorn  
(or, in your case the Kebnekajse I suppose), as I said: your mileage  
may vary by mean of a lot of parameters.



On 16 Jul 2006, at 17:56, Spiro Trikaliotis wrote:

> Hello,
> I just successfully programmed some EPROMs of mine (27C256).
> Ok, this is not very interesting in itself. Anyway, now, I wanted to
> clear them again. Thus, yesterday, I put them in the sun (the whole
> day). I hope them to be empty, but they are not. Both still contain  
> very
> many of the programmed bytes.
> Does anyone here have experience how long I need to put them in the  
> sun
> to completely erase them?
> Regards,
>    Spiro.
> -- 
> Spiro R. Trikaliotis
>        Message was sent through the cbm-hackers mailing list

       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail pre-2.1.8.