13 Feb 91 22:22
Heubi Matthias: Update D -> E by yourself! changing the ROM by software    

Hi Folks.
Here comes the long awaited solution! I wondered why HP hadn't posted
anything like this.

Many of you were complaining about some bugs in the Rev. D ROM.
Since there is mainly a workaround (inverting matrices should have one
though I actually don't know it..)

So let's explain it on the command SIN.
Assume you would like to install a workaround for SIN which
shows up HELLO on the screen instead of calculating a number.

write the following program:
/<< /-> arg /<< "HELLO" 1 DISP 1 FREEZE />> />>
Now store it in a subdirectory called 'xxx' named 'SIN'.
How to do that? Simply type "SIN" #5B15h SYSEVAL STO.
Now make xxx to a library (with the toolbox posted earlier) and
attach it to your homedirectory.

-> Any subsequent usage of SIN will display HELLO instead of calculating
a number.

Note that any previously stored program using SIN will still use the
REAL sine-function. To change this simply VISIT the program end store
it back!

To change the behavior of the SIN-Key too assign 'SIN' to this key.
Now everything is complete.
Consider that any usage of SIN is now stored as an XLIB call. Removing
the library will result a program to show up as /<< arg XLIB xxxx yyyy />>

WARNING: To use any program which takes advantage of this on a different
         calculator without the library installed, you MUST transfer it
         in ASCII mode. hovewer if all users use the same library ID's
         this should be no problem until you're transferring to a Rev. E.

I wonder why HP isnt spreading a RomFix-Library, since this would be
a cheap solution for people complaining about their Rev. XXX :-))

--> Now it's the turn of the '48 hackers to provide some fast (ML)
    workarounds for the various bugs.

PS. As you surely recognized, I got a 3.5 in English this term!

Disclaimer: I don't take any resposibility if you blow up
            your calculator using this instructions. 8-)


Matthias
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Matthias Heubi      / NeXT / Atari ST / HP-48SX /    mheubi@itrpe.uu.ch
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