Hack the CD64 1.30 bios... help, insights?

Hello, I am trying to find a way to hack or disasemble the CD64 1.30 bios to try and insert code to load from a HDD instead of a CD rom. I used to "hack" some pc games back in the day and am vaguely familiar with coding, so this is probably an uphill battle. The Bios I want to hack is the latest one 1.30.
My questions are:
1. Does anyone know of a source code anywhere existing for the bios? I can't find it any where if it does
2. Is it possible to disassemble the code, I can't figure out the dissemblers found online and they don't seem to let me change much or use CRTL + F to find anything.
3. Is there recommended hardware to flash the epprom in the CD64 for a good price? Are they universal fits?
4. I can't seem to figure out a way to run the bios in an emulator to play around with emulated memory. And I can't seem to get the rom in a full raw rom. There is the CD64 bios 1.30 direct upgrade rom which has a start menu to install so it wouldn't really be the ideal one to run in an emulator and the other is and ODD and EVEN file for a direct flash upgrade of the two eeproms. If I could combine those two I may be able to get somewhere but I can not for the life of me find a program that will merge odd and even files the only one i can find is winhex from winhex.com but it has a file output limit on the shareware version and the full version appears to be prohibitively expensive. Anyways if someone could help me get a leg up on something that would be amazing. Thank you.

 

Have you tried this? http://assemblergames.com/l/threads/n64-cd64-copier-bios-replacement.44784/

Edit: Oops looks like the links don't work anymore . Perhaps someone in its infinite wisdom was able to save them.

 

I have actually found a copy of this online and have it saved on my computer. I haven't installed it yet on my CD64 but from my understanding it is very limited in it's functionality. (and it doesn't support xterminator cheats that I love). I would much prefer to use the current Cd64 bios and just tweak the CD Rom loading to HDD (or compact flash). Maybe if possible add dump saves to HDD as well.... I don't have a printer port anymore for my paralell printer port adapter lol.

 

Sure! Make sure you read the .nfo file. It can also be found in one of the posts from the post http://assemblergames.com/l/threads/n64-cd64-copier-bios-replacement.44784/
That someone had made. I think the source code for his project can be found https://github.com/rvah/hdd64
Also, I think I should add that I made some interesting finding on the CD64.
I was able to insert a 6102 boot code into the raw bios image and load it into an emulator. The emulator only started up the boot picture of CD64 and then froze... which is further than I had been before lol.
I then had a strange idea to load this modified rom into my Everdrive with the CD64 connected to bottom (No power adapter or CD drive connected)... weird idea? I know. After two attempts at booting with the everdrive with the option "CRC checksum" highlighted I can boot into the CD64 menu. It is very strange lol. I may screw something up and the everdrive tends to get a little glitchy... I would not recommend doing this at home yourself, but I am a little nuts and am intrigued... perhaps with the everdrive abilities it can help me hack the CD64 bios.

 

I'm not familiar with the circuitry on the CD64, but does it use an IDE type connection to the cd drive similar to the dreamcast or is it custom? If it does use an IDE type bus then u could run the HDD in parallel with some software. U can build an EEPROM flasher very easily using a DB9 connector and some discrete components.

 

It is a IDE 40 Pin connector. I am unsure what you mean by in parallel with software, I think this is what I intend to accomplish. I might try and do this mod without flashing the chips (just using update by CD functions and loading file into CD drive.

I feel I should update anyone interested in the progress. I think I have my mind set on using the code from the custom HDD mod and inserting it into the CD64 1.30 bios.
I have been able to strip the HDDCF rom file from the bios installer and can now load it like a normal CD64 rom by CD (I have done the same with the CD64 Bios so I can test things out) I have it padded to 4MB file right now I am having issues trying to trim it down to 2MB for some reason even though in HEX it seems to be NUL code 2MB on. Doing it this way you also have to swap the CD drive to the CF drive.
The issue I have right now is that when I load the HDD it says "Drive not detected" It could be a number of things for me, perhaps the CF drive I am using is not compatible... the one I bought is this one: https://www.amazon.com/StarTech-com...rd_wg=JvOGD&psc=1&refRID=QW4BFWH7F2RTFENNJ5T2
I like this one because I can insert a filler for the space in the case that the CDDrive normally takes up. The recommended one from that HDD post is https://www.amazon.com/Syba-SD-CF-I...qid=1364660638&sr=8-1&keywords=syba+cf+to+ide
I'd prefer not to use that one because it doesn't fit as nice as the other. I may end up having to though.
The other issue maybe is because I don't have a CF card yet lol, so I am going to go to the local computer store today and buy one.
Attached to this post is the extracted HDDCF bios and CD64bios 1.30 with boot code inserted into the file. Both these files can be loaded like a game into the CD64 (It's kind of funny loading the CD64 bios into the Cd64 bios lol).

 

That's what I meant to ask, sorry for poor wording. As it is P-ATA, u could run a standard HDD alongside the CD drive (HDD set to Slave) until u can crack the BIOS to run HDD from boot. Any reason why u have opted to use a CF drive instead of a 3.5 HDD? Some of those adapters have been known to be temperamental with the Dreamcast version of this mod. Check with SWAT and Ozone as they have a vast amount of experience in this field. Good luck.

 

I like the parallel idea I may try that out, I have a tough time finding these older ribbon cable and connectors so I may have to order that online. I am using the CF mostly because the current current HDD mod is proven to run both hdd AND CF; with old HDD drives there are more moving parts and has more power consumption and these CD64s are known to fail because of the voltage draw of the CD Drive. Also the compact flash cards are quick and easy to load up more roms or homebrew.
Adding a picture of the CD64 with some of the parts I picked up today. They didn't have a longer 40 pin IDE connector, So I still need one of those. All the parts aren't screwed in tight so thats why it looks all crooked lol.

 

No that it matters but, is it me or does the 50pin female card edge connector in the pic above is missing a pin?

 

I took out Pin 18 and 43 for my self booting modification. The are connected internally to the boot cartridge. I shouldn't have taken them right out of the slot but they were all floppy after cutting the pins from the PCB. With the mod they are not used on the protected chip side of things.
Another Update: The CF reader I installed works with the HDD bios. Once again the one I bought is this one: https://www.amazon.com/StarTech-com...rd_wg=JvOGD&psc=1&refRID=QW4BFWH7F2RTFENNJ5T2
I bought an 8GB Sandisk CF card from my local store (the smallest the had). Following the instructions on that site I had to format the disk to fat16 and I resized the partition to 4GB (I think thats the max limit for fat16 I'm not sure). For me this is no good and hopefully can be reprogrammed for fat32.

EDIT:

I am having difficulty getting my head around the programs to hack or modify the CD64 bios. Nemu08 seems to be the best emulator to memory hack a rom... with how difficult this appears to be maybe it's best to start a new bios from scratch. So the source of "RVAHs" mod is at https://github.com/rvah/hdd64
Can someone tell me what programming language this is?