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Re: Transwarp Card problems



Hello Michael.

Actually it's not that some EPROM's are better then others (except for 
speed), it's a factor of time.  Most data sheets specify that a programmed 
EPROM (and most other devices too) is only good for about 10 years.  Now we 
all know that the programming can last longer then that, but there's 
guarantee that they will not loose bits from time to time.  Really that's 
the greatest risk.

When you program an EPROM you're 'trapping' a small charge in a cell.  The 
computer in return can tell how the cell is charged - i.e. 1 or 0.  It still 
amazes me how even over a few weeks that the cells in these type of devices 
don't loose their charge.  Most if not all complex devices are programmed 
like this too these days.  Makes one wonder what will happen in the future 
to old computers.  Will a 20 year old CPLD or FPGA still hold its program? 
Cracking and cloning those devices is monumentally harder then any PAL or 
GAL - so don't ask! ;-)  Although I have read about services that brag how 
then can crack an FPGA.  Must be expensive though.  It can be around $1000 
just to crack a GAL!


-- 
Henry S. Courbis
www.GSE-Reactive.com
Apple II Series Legacy Hardware - Come take a look at what we have to offer!


"Michael J. Mahon" <mjmahon@aol.com> wrote in message 
AoudnaLlKePli_fZnZ2dnUVZ_tydnZ2d@comcast.com">news:AoudnaLlKePli_fZnZ2dnUVZ_tydnZ2d@comcast.com...
> Wayne Stewart wrote:
>> If he has the capability, it might not hurt to burn a new EPROM from an
>> image. The original EPROMs have a tendency to get a bit flakey after a
>> couple of decades
>
> That's interesting.  Maybe we should start compiling data on which
> manufacturer's burned marginal EPROMs.
>
> I have EPROMs that were burned in the late 1970s and have never
> found any data loss.
>
> -michael
>
> Music synthesis for 8-bit Apple II's!
> Home page:  http://members.aol.com/MJMahon/
>
> "The wastebasket is our most important design
> tool--and it is seriously underused."