Topic: Multi Bios Switch Hack (Read 51 times)

soliant · « **on:** February 15, 2004, 05:40:00 PM »

I've been reading alot about the a18/a19 switch hack to allow boot from 4 banks of tsop (if you have 1mb bios).

Anyhow, I know there was a lot of discussion about being careful using resistors (due to heat) and only using spsd (3 prongs) switches for a19->gnd->vcc

Well, just wondering if someone can confirm the hack with 2 spst switches a18->gnd and a19->gnd ? (does this work w/out risk of high heat)

Does the gnd wire get soldered to the middle prong on spst switch ?

TIA <

lordvader129 · « **Reply #1 on:** February 15, 2004, 05:48:00 PM »

just using SPST switches will severely limit the bios you can use, youll only be able to use really old version-specific bios (no current multiversion bios)

a18 or a19 goes to the middle pole of the SPDT switch

not sure about the heat issues, have to wait for someone esle to answer that one, ive done a few switches though and havent run into any problem (no resistors) <

soliant · « **Reply #2 on:** February 15, 2004, 05:53:00 PM »

lordvader129 · « **Reply #3 on:** February 15, 2004, 06:00:00 PM »

because simply grounding the point only blocks the banks above it, for example, if you grounda18 and leave a19 open, it blocks bank 4, so the bank 3 is booted by default (the highest bank is always booted), however the xbox can still see banks 1 and 2, and it will compare the bios in all 3 banks, if the bios dont match up (multiversion bios wont) it will frag

where ground blocks banks above, 3.3v blocks banks below, so by putting a18 to ground (blocks bank 4) and a19 to 3.3v (blocks banks 1 and 2) you can boot from bank 3 ONLY, and it wont be able to see any other banks so it wont matter what bios you have in them

hope that explains it without too much confusion, lol

and BTW, the Live 1.0 dashboard is 4920

This post has been edited by lordvader129: Feb 16 2004, 02:01 AM <

soliant · « **Reply #4 on:** February 15, 2004, 06:09:00 PM »

O.k.
That makes sense to me.

However, please check this tut. out that I am following

http://xbox-scene.com/articles/multibios-tsop.php

It does not state the info you gave me, maybe it should ? Actually in this tut. the author uses an example of Evox 2.5 + x2 4973 + Original + Evox 2.6 ,

so is this tut. valid or not ?

thanks again. <

lordvader129 · « **Reply #5 on:** February 15, 2004, 06:33:00 PM »

thos ebios are all version specific, and the tutorial says this....

soliant · « **Reply #6 on:** February 15, 2004, 06:42:00 PM »

Shit man, I missed that, and it was even in bold

Alright I am returning my spst to radio shack for spdt, then I will be able to have bootup only see one of the four banks, and not care about others.

(white space gets trimmed)

gnd-> a19-> vcc

thx for educating the non(switch) educated.

This post has been edited by soliant: Feb 16 2004, 02:43 AM <

lordvader129 · « **Reply #7 on:** February 15, 2004, 07:04:00 PM »

for a 4 way split youll need 2 SPDT switches

gnd-> a18-> vcc
gnd-> a19-> vcc <

ideas_man69 · « **Reply #8 on:** February 15, 2004, 07:55:00 PM »

so if you wanted to use the switch, do u flash a 1mb bios that has say m7+m7+x2 4981+x2 4981 before the switch is installed? cos i installed a switch into mine and it didnt let me flash any multi bios's on to it afterwards.

so someone please correct me if im wrong.. but this is how i sort of see it...

-make a 1mb bios made out of 2 x 512 (or 4 x 256)
-flash the tsop with it
-install the vcc-a19-gnd switch

yeah? no?

<

lordvader129 · « **Reply #9 on:** February 15, 2004, 08:03:00 PM »

that will work, but ive found it better to install the switch first, cuz then you can only flash 1 bank at a time (so if you have a bad flash you can boot from another bank still and refash the bad one) <

Dreamcazman · « **Reply #10 on:** February 15, 2004, 08:05:00 PM »

The heat issues are to do with the 5v leading to one of the points on the MCPX chip, increases the temp by a 1-2 degrees. If you stick a heatsink on it, it'll fix the heat problem..

Now, ideas_man69, you can do it that way or the other way is once you install the switch or switches, boot the Xbox on the first bank, than flip the switch to the second bank (while Xbox is on) and flash.

Reboot and then flash the 3rd and then 4th banks.

If your TSOP is already flashed with a hacked Bios, it'll be easy to do in Evox, otherwise you have to use a game save hack, etc to flash the first bank. <

ideas_man69 · « **Reply #11 on:** February 16, 2004, 01:36:00 AM »

terrorvis · « **Reply #12 on:** February 16, 2004, 03:45:00 AM »

Dreamcazman · « **Reply #13 on:** February 16, 2004, 09:55:00 PM »

Ideas Man - To be honest, I never tried it with a 512K Bios. Once I put the switch in my Xbox, I flashed the other side with a 256K bios and it worked fine. Evox auto sizes the bios file if not correct size. Dunno why it wouldn't flash a 512K bios...

I use 4981.67 on both sides. I mainly put the switch in so I can recover easily. I play around with different colour mods etc.

Terrorvis - I would advise you stick a heatsink on even if you aren't doing this switch mod. I've heard of Xboxes dying because the MCPX has fried itself, and that's in unopened, unmodded Xboxes! M$ should've gone to the extra expense.

You could also do what a few other modders have done. They've cut the trace at A19 that leads to the MCPX chip. I personally don't want to do this and I'd much rather use a heatsink. <

terrorvis · « **Reply #14 on:** February 17, 2004, 05:39:00 AM »

Author Topic: Multi Bios Switch Hack (Read 51 times)