scrumpyjack

Because the Function keys routine is not held in JO.SYS.

Why? to learn more plus i change F5 so Safe Mode is safer.

@dencorso that's great works a treat i had to wait an hour to test it as my keyboard wouldn't work lol, it all making sense. the ah,2 is asking the state of Shift and then testing for it. it plain as day now studying, but still learning. i was too busy patching the scan code 58 for Shift F5, rereading the article i posted it makes more sense. good teamwork and thanks again. what interests me now is turning off the @ ^Z on the keys. it be int21. http://courses.ece.uiuc.edu/ece390/books/a...html#HEADING3-1

no because that hijacks the thread and has nothing to do with my topic! just kidding! i pass that question onto dencorso.

If it make you happier. you can delete my thread at your forum as we the only 2 contributing members and i stick to this one as you visit here too . The real question is how many forums are you on at anyone time lol. Is it not triacontahedromensional? that is very eerie. i was at that comical post several days ago and only discovered it through some obscure link. very amusing.

I initially thought using INT9 would intercept the keys. Researching IO.SYS there is snippets of IO.SYS but no full disassembly. I found alittle source code and old viruses that inserted themselves into the free space of it. Finding a dos debugger is another task but that was before i found out more. If you want to help along, expand your knowledge, or crazy enough. here is some useful key scan codes of BIOS and DOS interrupts. http://members.tripod.com/~Vitaly_Filatov/...sm/asm_021.html http://www.htl-steyr.ac.at/~morg/pcinfo/ha...ts/inte1at0.htm http://courses.ece.uiuc.edu/ece390/books/a...html#HEADING1-5 The int 16h and it's flags. http://courses.ece.uiuc.edu/ece390/books/a...html#HEADING3-1

@Drugwash sure that works too at the time there were several jumps going back. changing JE to JNE or vice versa at several places has the same effect of course. instead of lots of NOPS everywhere i was trying to do a smarter patch and take out the value.

@dencurso Thanks for the welcome and the update. This is a project that i have learned alot and has been fun and interesting. Patching that jump is better, works good and I see why thanks for the explanation. I read your comments it coming from the BIOS about the Shift. It is harder to trace. Patching the Shift key in the same routine as the others does nothing. It seems the Shift is in a far off location to the rest of the other routines. Not to be outdone i have managed to null the Shift from acting out but it still loads 'Windows is bypassing your startup files.` This must be being programmed before.

Hello, I didn't realise it was such a small world between the 3 forums as the net is a vast place. I also did that to test the knowledge of the forums. Apologies for that. It seems there's few DOS forums these days. I had failed to find any, seems they all died out. When you mention DOS they think of CMD box in XP! It nice to read the interesting comments as i didn't expect too much response especially after the first negative comment the mods deleted. I tried another forum trying to find users who have decent knowledge. I guess my impatience and asking a far out question and getting questions on why do that instead of help i decided to study and go it alone. Yes i should of waited longer for a response but i was uncovering more at the same time and i was trying to grasp assembler. As IO.SYS is DOS related i posted on Computing.net as i was hoping for DOS diehards such as Secret Doom, Laurence types of old with the tricks, knowledge would know but seems less frequent in these times. In the end my desperation helped me push forward and discover more. Rest assured i wont post on forums like that and i didn't post on anymore than what you know about. Thank you all for helping and for dencorso's informative entertaining comments and Hello to Jaclaz here too . @dencorso thank you for your help. yes the patch is not satisfactory and as i said on Jaclaz forum i need to improve, but just 1 byte disables all the main keys apart from the shift and needs to be held down. I scraped that. I will have a better solution. Your patch goes to the boot menu in essence making Jo.Sys still work which is what i what i accomplished with the patch i did. You say it will wait forever, yet if the key is pressed 2x or held down it works but is not ideal. I guess this is flooding the buffer is it not. If the menu in IO.SYS was really seen as disabled by IO.SYS, Jo.sys would not work which comes into effect when MSDOS.SYS is modified with BootKeys=0.

We have not moved far on. What you think is on a bootable CD-ROM disk???...DOS! I want to disable it for security reasons.

Ok i have a W98 boot disk. I need to disable the F8 startup menu. This can be done with 6.22 by editing MSDOS.SYS and putting 0 on certain Boot [Options]. This has no effect on W98 disk and actually makes it hang. I thought if i can patch IO.SYS to disable F8. It could even be command.com but i believe it be IO.SYS as that gets loaded after. I looked up the keyboard scan codes and hex 42 00 is coming up on F8. I also looked up what interrupts use the keyboard. INT9 INT21 and INT16 seem to be the ones. I went through the code and 4200 comes up a few times but too many times. Does anyone have a clue on assembler or can help me find the right opcode to patch. Thanks.

you need to start with PYTHON language. It best for learning.