Dreamcast Dev Bios (Part 1)
This tutorial is from www.mmmonkey.co.uk
UPDATE
Looking for a cheap reliable source for this chip, I've bought some from Bad_Ad84 via assemblergames, he even offers a flashing service :-) If you buy a pre-flashed chip, then you can simply remove the old BIOS and fit the new one, you still need to lift and solder leg 44 as per the notes below, and lift leg 1 and solder it to 23, and if you've got an early motherboard then you'll need to pay attention about powering the chip (legs 1 and 23), as per the notes below. I have put some photo's at the end of this page.
Link83 did some amazing work and combined the Dreamcast Dev BIOS (different startup screen) with the Retail BIOS and made it truly Region Free.
Have a look at the startup animation which has been hacked into the BIOS, it's from a DC Dev machines and looks great :-)
Why perform this mod? Well you'll end up with a DreamCast which is different to most others, plus it will be truly region free, the current 4 wire modchips need you to switch the console off and back on again if swapping between different region discs. This one skips any region checking at all.
Link83 UPDATE - Extra info about that early VA0 DC Motherboard:
the VA0 Dreamcast motherboard (Mainly early Japanese and USA consoles) need a 5V flash chip, and that the VA1 and VA2.1 Dreamcast motherboards use a 3.3V flash chip. You can tell which motherbaord will be inside your Dreamcast by looking for a small circled (0) (1) or (2) on the silver sticker on the bottom of the casing.
DarthCloud has also written some extra info on the subject here.
I have to say a BIG thanks to Link83 for experimenting with the BIOS, DarthCloud on ASSEMblergames for all the detailed info about fitting the chip and the Russian DC-SWAT team for the original DreamShell disc which I modified to make flashing Link83s BIOS easier and also for their original installation diagrams.
Start by lifting leg 12 of the original bios chip, I gently heat the leg where it joins the motherboard and then with a scalpel I lever it up, and carefully straighten it with a pair of pliers.
Then start on the Flash Chip 29LV160TMC-90. We need to start with straightening the chip legs
Then we need to bend them again, this time they should just have one bend in them. Hold the chip vertically so all the legs are pressed against a flat surface. Then push the chip so that all legs are bent at a 90 degree angle to the chip, repeat on the other side.
Then test fit the new chip onto the existing chip. The legs will probably be a bit too short, but that's okay, we can still solder them together.
Remove the new chip, and now prepare the existing chip. I was worried about adding too much solder to the BIOS chips legs and joining two or more together. So decided to work my way around with a continuity meter and discovered that legs 32 and 33 are already linked together. When I finished preparing the legs, I did the same check.
We want to add a small amount of solder onto each leg, once you pickup the technique for this it won't take too long. I hold the tip of my soldering iron on the very top of the leg (on the red dot in the photo), it heats the leg up, be ready to immediately add a small amount of solder to the leg, it should quickly take to the leg and cover it. The photo below shows I've done legs on the left hand side.
You need to now straighten some legs on the new BIOS chip as we don't want these soldered to the old chip legs. Gently bend legs 1, 12 and 44 out flat (also do leg 23 if fitting on a VA0 motherboard).
Now I place the new chip on top of the old one, and dragged the solder up from the old leg onto the new leg. The photo below shows I've done the first few legs on the right of the photo, the red dot is where I place the soldering iron tip, and then drag the iron up onto the new legs, taking some solder with it.
Work your way around and do this to every leg. Don't worry too much if you don't join the legs up first time. The photo below shows a couple of legs that didn't join up, this is easily fixed though.
