Re: A92: Flash ROM
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Re: A92: Flash ROM
Nicolas Ochem schrieb:
> Hello
> I was thinking about a thing which could be a great way of increasing the
> archive memory on the TI-92 Plus.
> Since 1995, Ti released the TI-92 with the ROM in a cartridge, who was put in
> the place the Plus module is now. This was called "external ROM". That was
> to make it possible to easily change the ROM in the future.
> But later, TI realized that the Flash technology could be a better way of
> updating ROM, and so they stopped putting ROM in a Module and soldered it
> directly in the "motherboard" of the calculator. These ROMs were called
> "1.11 internal" and "1.12 internal".
> Now, the Plus module is there, with a totally new ROM support.
> But, in the case of the calculators, who used to have the internal 1.11 or
> 1.12 rom, and now have the Plus module, like mine, there is actually 2 ROM,
> one totally unused.
> I think they must be lots of common points on both rom.
There are, as you can find out using a simple string searcher on the roms,so, if
you know correct addresses in the 'old' rom you can call routines there.
A.K.
For example, some
> Plus apps are exactly like the former version (for example, data/matrix
> editor, text editor, y=, table, etc...). So, I think both ROM have a lot of
> data in common, and consequently in duplicate.
> In this group, some of you found out that the former ROM can still be
> accessed :
> > $200000-$2fffff: OLD TI92 ROM
> So, in the Flash ROM, we could replace the parts which are in duplicate by a
> single reference to the place in the old ROM where the corresponding data. I
> think that if I'm right, we could earn about 500 ko of archive memory.
> What do you think of that ?
> Nicolas
>
You are right, perhaps TI could do that, but it wouldn't provide more archive
memory as this starts at $5a0000(sometimes at $590000, I don't know why )with
lots of free space below. So, you must find out all the system variables that
deal with the archive and change them to a convenient point. Result: disassemble
the rom to find out how this works, that is like looking for a pin in a heap of
hey. A.K.
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> <DIV><FONT color=#000000 size=2>Hello</FONT></DIV>
> <DIV><FONT color=#000000 size=2>I was thinking about a thing which could be a
> great way of increasing the archive memory on the TI-92 Plus.</FONT></DIV>
> <DIV><FONT color=#000000 size=2>Since 1995, Ti released the TI-92 with the
> ROM
> in a cartridge, who was put in the place the Plus module is now. This was
> called
> "external ROM". That was to make it possible to easily change the
> ROM
> in the future.</FONT></DIV>
> <DIV><FONT color=#000000 size=2>But later, TI realized that the Flash
> technology
> could be a better way of updating ROM, and so they stopped putting ROM in a
> Module and soldered it directly in the "motherboard" of the
> calculator. These ROMs were called "1.11 internal" and "1.12
> internal".</FONT></DIV>
> <DIV><FONT color=#000000 size=2>Now, the Plus module is there, with a totally
> new ROM support. </FONT></DIV>
> <DIV><FONT size=2>But, in the case of the calculators, who used to have the
> internal 1.11 or 1.12 rom, and now have the Plus module, like mine, there is
> actually 2 ROM, one totally unused.</FONT></DIV>
> <DIV><FONT size=2>I think they must be lots of common points on both rom. For
> example, some Plus apps are exactly like the former version (for example,
> data/matrix editor, text editor, y=, table, etc...). So, I think both ROM
> have a
> lot of data in common, and consequently in duplicate.</FONT></DIV>
> <DIV><FONT size=2>In this group, some of you found out that the former ROM
> can
> still be accessed :</FONT></DIV>
> <DIV><FONT size=2>> $200000-$2fffff: OLD TI92 ROM </FONT></DIV>
> <DIV><FONT size=2>So, in the Flash ROM, we could replace the parts which are
> in
> duplicate by a single reference to the place in the old ROM where the
> corresponding data. I think that if I'm right, we could earn about 500 ko of
> archive memory.</FONT></DIV>
> <DIV><FONT size=2>What do you think of that ?</FONT></DIV>
> <DIV><FONT size=2>Nicolas</FONT></DIV></BODY></HTML>
>
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