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TI99/4a "killer poke"?


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#1 notwhoyouthink OFFLINE  

notwhoyouthink

    Star Raider

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Posted Thu Jul 20, 2017 9:40 AM

Does the TI have a killer poke... Or, killer call load, i suppose?

I do not mean poking a value that causes a system crash or reset... I mean literally has the potential to damage hardware.



#2 --- Ω --- OFFLINE  

--- Ω ---

    TI-Runner

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Posted Thu Jul 20, 2017 9:50 AM

Not that I've ever heard of.  But honestly, even if I knew of such a thing, I'd never tell anyone out of fear of some malicious person embedding it in a trojan program.



#3 apersson850 OFFLINE  

apersson850

    Moonsweeper

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Posted Thu Jul 20, 2017 9:54 AM

What you can do to destroy hardware is turn some of the programmable I/O points on the TMS 9901 PSI in the wrong direction. If you set an output against an output, you may fry the chip. But you can't do that with just a "poke".



#4 mizapf ONLINE  

mizapf

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Posted Thu Jul 20, 2017 11:14 AM

Well, ultimately, there is a way: You can transfer control to any machine code by setting the interrupt hook 83C4. So you need several pokes, but yes, you can.



#5 majestyx OFFLINE  

majestyx

    Chopper Commander

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Posted Tue Oct 3, 2017 10:36 AM

In Chapter 2 of Teach Yourself Extended BASIC (PHD 5019) where it explains what CALL LOAD does, it gives this warning:

 

CARELESS USE OF "CALL LOAD"

MAY CAUSE SYSTEM FAILURE.

 

USE "CALL LOAD" ONLY AS

INSTRUCTED IN THE DOCUMEN-

TATION FOR ASSEMBLY LANGUAGE

SUBPROGRAMS.

 

Found that to be quite interesting. Not sure if they meant it would lock up/crash the computer or actually frying the hardware.



#6 RXB OFFLINE  

RXB

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Posted Tue Oct 3, 2017 11:42 PM

Using RXB I turned on the Floppy DSR and using a CALL LOAD wrote over drive sector zero of a floppy disk.

Not intended but it did take more then just a CALL LOAD to do so.



#7 apersson850 OFFLINE  

apersson850

    Moonsweeper

  • 421 posts

Posted Wed Oct 4, 2017 4:13 AM

 Not sure if they meant it would lock up/crash the computer or actually frying the hardware.

They were referring to a lock up/crash only.






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