Connecting IDE disks & ISA (network) card to Dreamcast

[OzOnE]

Hi, all,

I've just tested the adapter with the CF card code, and it works fine.




There are a few minor issues though...

Firstly, you might notice that the plastic part of the IDE socket (with the notch) is reversed. This is because I wanted the socket on the underside, to make it neater.

I'll see if I can remove and replace the plastic part later instead of cutting a new notch. Some 40-wire IDE cables don't have a notch anyway, and it doesn't matter whether you use a 40-wire IDE or 80-wire "UDMA" cable on the DC.

I'm having a hard time finding the tiny oscillator modules for the adapter...

The footprint on the board is for an Abracon ASF series module, but that is only 5x3mm and I can't seem to find the 33.8688MHz version to buy easily online?

That means the adapter can't currently be used stand-alone, so will need to be used with the GD drive plugged in at the same time.
(The GD drive will end up about an inch higher though.)

EDIT: You can of course connect a (bigger) osc module via the pin header.
I'm not entirely sure if that will allow it to boot into Dreamshell (without the stock GDD connected), so I'll have to find an oscillator that I can test later on.
It's possible to use a slightly faster or slower osc frequency, but that will cause the audio to speed up or slow down too.

The other problem is that the adapter can't be used with the motherboard inside the original case.
I thought I'd taken that into account when I did the design, but it seems I forgot about it and made the board a bit too big...



These are prototypes though, so some of these issues were to be expected.
Also, if you leave the stock heatsink / shield on the mobo, the plastic part of the IDE socket sits touching the shield (but works fine).

The adapter itself works fine for using a CF card adapter and developing the code. (SD / SATA adapter not tested).

It can actually read using both PIO and DMA, but there is that issue with the DMA "busy" flag on the DC never going low?

I also tried plugging the GD drive directly into the PC via a USB adapter, but it of course didn't show anything (even in Disk Management).

There is a Linux kernel driver available, so it should be possible to port it to a Windows driver??...
http://www.cs.fsu.edu/~baker/devices/lxr...om/gdrom.c

You can also use two adapters for extending the cable between the mobo and GD drive.
I will test this today, as I need to solder some more plugs / sockets.

@SWAT and @cybdyn - please PM me your addresses and I'll get some adapters sent out to you as soon as I've had chance to solder them.

I'd like to send you TWO adapters each - do you have a preference for the type? (all types will have the IDE port on of course)...

Mobo (bottom) plug + GDD (top) socket.
Mobo (bottom) plug only.
GDD (top) socket only.

Unfortunately, I can't yet sell these to too many people unless they can help with the coding.
Please understand that the above issues will be fixed in the next batch too. These are just dev prototypes atm.

It is already possible to load ELF / BIN programs to run under KOS, so I'm sure it won't be long until we can boot SD-ISO's with them.
But, just in case people don't know...

*** Disclaimer - These are NOT yet booting game images! ***

OzOnE.

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Oh, thought I'd post a couple more photos, to show how high the GD board "hovers" with the adapter in between...
http://oi39.tinypic.com/2j3mr04.jpg

And here is the IDE cable routed to the CF adapter. It can be made MUCH neater of course, but it's just a test setup...
http://oi41.tinypic.com/2gxnts4.jpg