How to add IDE CDROM support to a Soundblaster 16, CT2890? \ VOGONS

How to add IDE CDROM support to a Soundblaster 16, CT2890?

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First post, by perhenden

Posted on 2021-01-26, 08:22

perhenden Offline

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Hi,
I've got this CT2890 (revision 01) with solder pads for an IDE header.
I would like to add IDE CDROM support by adding the header and other required parts.
Did anyone have success doing this before, even on another Sound Blaster 16 model?

Comparing with a CT2890 variant model (also revision 01) with IDE CDROM support, I see that the nearby LS244 chip is missing on my card. This looks related to IDE operations, as there are traces going to that location from the IDE header. Also there is a jumper, IOCHRDY ("io channel ready?") to add. For the largest chip, my model has CT1705B, while the other has CT1705.

There are a number of capacitors missing far away, on the other end of the card, as well as a chip close to them, TEA2025B (an amplifier chip).
Can I ignore them as not related to IDE operations?

If I do add all the missing parts, will the IDE CDROM support work? Or is there for example a different ROM required for the card to report/register its IDE controller to the bios/otherwise?

Here are images of my card (front and back), as well as a model with the IDE header and chips factory installed.

Model without IDE header:

Model with IDE header:

Reply 1 of 2, by dionb

Posted on 2021-01-26, 10:00

dionb Offline

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The stuff on the right hand side is a speaker amplifier, it's unrelated to the IDE functionality. It looks like you just need the LS244 and the passive SMD bits around it. I have no idea whether the CT1705 vs -B makes ant difference.

Reply 2 of 2, by mdog69

Posted on 2021-01-26, 18:43

mdog69 Offline

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You might have to change some data in the 8 pin EEPROM to the left of the CT1705 to tell the chip that the IDE is present, or to provide the PnP data to allow the IDE to be discovered.

There is also a slim chance that CT may have used devices with broken IDE support on non-IDE cards. (This wouldn't stop me trying - the lack of PnP data would be my show stopper)

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