"Let's make GD ROM emulation happen" Facebook group.

As I've said when it comes to coding I'm pretty much a dummy ATM. But I might be able to help with the debugging and DC SWAT issues. I do know for those who have a modded BIOS chip installed they can burn SWAT to the BIOS directly so you don't need the SD adapter or CD-R to boot. It boots directly. And I read of a method for using he serial port to get decent transfer speeds over serial to USB connection. Upwards of 3 MB a sec transfer speeds the article claimed. Most times it runs half that but should still be plenty fast for debugging. Here's the page with all the details: http://dknute.livejournal.com/25454.html

As for the CF use, I plan to use all sorts of IDE stuff. I even have a 44 pin IDE to SD adapter that I wanna test once this gets far enough to do so. I just liked the idea of MO disks to keep that retro feeling of swapping a cart or disc out and having it better protected from everything.

 

That was the other problem - the version of the SWAT BIOS which boots straight into Dreamshell doesn't contain the required parts of the stock BIOS!
So, you have to use the "Dreamshell with BIOS" version to boot retail games, or have a chance of getting the CF card working.

I could hook up a USB-to-serial adapter like on Deunan's site, but then I couldn't boot from SD to use the "Dreamshell with BIOS" flash.

As I say, I'm sure there's a way to get serial debug working while still having the SD mod attached, but it would require SWAT to modify his code slightly.
I should ask him if he's had any progress really. He said he will try to implement the CF method under Dreamshell. He's probably very busy though?

That's the other good thing about this method - it uses a connection which isn't used by anything else.
The GD drive can be left connected as normal and the CF / HDD will hopefully be transparent to normal CD / GD-R games.

If support for this is added to Dreamshell, we'd just need to get some adapters made up.
The only other issue is that the adapters will add quite a bit of height if you'll be leaving the GD drive in place, so the DC's original lid might not fit?

The aim is to do away with the GD drive altogether, but another adapter could be used to connect it to the PC for making GD rips.
(There are already some basic drivers available for Linux apparently. It would be interesting to see if they actually work OK?)

It's possible that the CF / HDD might interfere with the GD drive, but I'm banking on that not happening...
The games would need to send the init command specifically for a Slave IDE device, so it's unlikely to affect it.

Would be fantastic for the guys over on benheck to use a 2.5" or 1.8" laptop HDD in their portables. :cool-new:

And that's a huge amount of storage which wouldn't be possible with the SD card mod.
(The only SD-to-IDE converters I've seen work in the opposite direction, otherwise we could have booted DS from a hard drive).

btw, I even tried to get the second serial port working on the DC. I'm convinced the TXD / MD7 pin on the SH4 could be used for debug output.
This signal should be available on one end of resistor R122. I don't think this TXD is normally used for anything apart from setting the region at power-up?

The RXD signal is also available on one end of R115. If only we could get the damned thing working. :moody:

Even then, I'd need to keep the debug code small when using GD redirection because the IDE code needs to stay resident in memory (like SWAT's bootloaders).

The ultimate method would be to modify the stock BIOS so it will boot from CF / HDD. This is possible in theory, but I'd need help with injecting the code into the BIOS image.

OzOnE.

 

the SPI bus can support multiple devices with Chip Selects...

Hack together a combined SPI & SD Card combo adaptor - with an AVR in the middle as a physical proxy - except it will have extended commands to switch between the SD card and a USB serial port (possibly already attached to the AVR board :smile-new...

Also about the second serial line: you'd need to enable a bunch of things in the IO registers, probably maybe change some interrupt routines at the minimum...

Don't forget about the maple bus either - you might be able to push some data across that as well...(Serial port on a controller...madness:congratulatory

 

http://i049.radikal.ru/1212/4d/5cf805a35e3c.png
http://s018.radikal.ru/i523/1212/d3/4c93c1455dab.png
http://s019.radikal.ru/i614/1212/4d/4cf8cafcb35a.png

 

Now to finish the wiring and get a prototype made. Then the software can be tested.

 

you can also give advice, where better put the sd slod, or how many ide ports i need use one or two.

 

1 IDE port should be fine. If this implements the PC style IDE bus then 2 devices should be able to be plugged into 1 port. 2 ports and support for 4 devices might be a bit overkill. Or not...

As for the SD slot placement, It might serve well to make it remote on separate PCB. So the user can decide where to put it should they need to remove the card for anything in the future.

 

Imho, single IDE connector, with room for ide2sata adaptor for compatibility and a usb port for transfering files from pc to DC => PERFECT!

 

Hmm sounds nice put me down for a pre order once you done this.
Cant Wait.

 

I lost my hopes with a few comments I saw on the other thread a few months ago.

It's just unbelievable that the dreamcast will finally get it done!

 

Let's not jump the gun now. Many have gotten this far or further before giving up. Until I test a working prototype I'm going to play it safe by not expecting much of anything.

I have worked out a deal to help beta test the design once working prototypes are made since I seem to have all the other support hardware needed on hand.

 

If you got your hands on a proto, take detailed pics of the progress.

I believe many people will enjoy "big brother" the process

 

^ That'll be up to cybdyn since he is designing it.

 

generally i still make it for myself, but i saw soncdude10 asked if anybody still working on that .. and i show my progess...

3d model made from real scheme but now on Altuim Designer. i showed it here when it was draw on Orcad 16.

i need route wire on board...but i can't make it faster... it,s not my officially work, it's hobby... but i'm not going to stop.

 

also i plan finished with similar project for ps1 first, then for dc.

 

http://dknute.livejournal.com/41548.html

Duenan progress update on the GD EMU

 

Still having issues with the DMA clocks I see...

 

it's good to hear something new from Deunan...but He works independently from any help of other people and without sharing any sources, so what we gonna do? wait? that's why i start make my own board, and maybe that's why all things go slow.

 

OK guys i had other SPU-3200 16PIN from other place and only thing i had to do was readjust the spindle hub and worked with Gd-ROM and mil CD.

 

Can I suggest a 90-Degree rotated IDE Header,
If the IDE header is at the edge of the bridge PCB - then any 3rd party IDE-TO-SATA adapter board will work.