[Coco] About those EPROMS...

[Dave Philipsen]

Ok, but the ROM itself, even if encrypted, must be read in order for the 
program to be executed.  The processor places an address on the address 
lines, strobes whatever output enables are necessary, and the data at 
that address appears on the data lines.  Right?

On 4/9/2015 6:47 AM, spereira1952 at comcast.net wrote:
> It's pretty straightforward - the ROM is encrypted, and another device has the key that is used only during runtime to allow the code in the ROM to be decrypted. This method is widely used today in devices that are manufactured overseas to protect a company's intellectual property from being stolen.
>
> smp
> - - -
> Stephen Pereira
> Bedford, NH 03110
> KB1SXE
>
> ----- Original Message -----
>
> From: "Dave Philipsen" <dave at davebiz.com>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Thursday, April 9, 2015 12:58:24 AM
> Subject: Re: [Coco] About those EPROMS...
>
> How could that be possible? If a processor executes a program from a
> ROM it must read the data stored in it one byte at a time.
>
> On 4/8/2015 8:19 PM, Stephen H. Fischer wrote:
>> For ROMs there were some made that you could only execute the program in the ROM.
>>
>> That made even reading the contents by addressing the ROM one address at a time not possible.
>>
> SHF
>
>
>
>