Re: A89: Flash ROM or Archive


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Re: A89: Flash ROM or Archive




Here's what is likely:

The custom 68k processor has ROM in it which contains instructions to
somehow program the flash with the ti-os.  That way if the flash should
become trashed TI can re-load the software on it.  Perhaps some other
routines are also located in the ROM.  This also makes it so TI can
program the calc as it goes out the door, instead of programming the
flash, and then soldering it to the board.  The rom could probably be
considered to be much like the BIOS on a motherboard.  It points to a
specific location in the flash where the processor is to start executing
code.

The flash contains all or most of TI-OS.

Also, you are using the word ROM incorrectly.  ROM refers to Read Only
Memory.  Generally it is written once and never written again.  If you
want to be really technically accurate, TI probably uses PROM, which
indicates that it is programmable once.  Strictly speaking, ROM is
memory which is formed when the silicon is etched and can never be
changed.  It is used when you need a few million devices with the same
program made.

It would be more accurate to say that TI will be supplying Flash
software and software updates.

The archive is kept in a part of the flash chip which is not used to
store the OS.  The data in the flash is not lost when the power is taken
away, but I imagine that the TI-OS 'initializes' part or all of it when
power is re-applied.

-Adam

Brad Barger wrote:
> 
> I am getting confused I have heard that the Archive memory is where all ROM updates will be stored and I have also heard that updates will be stored to either the actual ROM chip or a second Flash ROM chip. Which is true?


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