DTS-6D modifications for SD card playback

[Josh Jones]

I am happy to report that the ZuluSCSI modification seems to work well. Here is a DTS-6D that I have modified. The ZuluSCSI is mounted in a bracket that was 3D printed by a friend of mine, and then mounted in a 5.25" to 3.5" bay adapter. I also drilled a hole and added an activity light to the board using the header pins. The ZuluSCSI is bus powered and requires no additional connections. I also modified the unit to use a new style ATX supply using an ATX to AT power supply adapter cable. I did have to lengthen the leads for the switch to reach the front panel.

All of the existing CDROM drives were removed, and the double bracket modified to accept two vent panels I had laying around. The 5" monitor was installed on the panels after mounting modifications were made. A CGA or VGA ISA card is added to the motherboard for monitoring. The bus order doesn't matter according to the DTS documentation, and this is one of the older units with a 486SX in it. A molex pigtail was used to power the monitor from the ATX +12V bus.

The ZuluSCSI can emulate up to 7 discs from one SD card. Each DTS disc is ripped to an ISO file, and then renamed to CD1.ISO, CD2.ISO, etc. The CD is an important part of the file name, as it instructs the ZuluSCSI to emulate a CDROM drive with appropriate sector size and such. The number in the file name instructs the ZuluSCSI of which SCSI ID to advertise on the bus. It is important not to load more than one set of DTS disc ISO's on the SD card, but adding a trailer disc is OK. With the low cost of decent SD cards, this means ideally you set up one card for each feature.

I hope this information is helpful to those wanting to try this.

Josh

[Steve Guttag]

I think you just violated your DTS warranty.

[Marco Giustini]

this is so cool! I used to run my DTS player with a VGA card to monitor that screen - the number of drops and the buffer size was an important feedback to understand whether the dreadful Toshiba drives were about to bite the dust!

This is so cool. Can you share the design for the brackets? What's happening with the video output?

Also, super interesting about the SD card method, kudos for finding that solution. I think I tinkered with an HDD many years ago but I couldn't make it work. Even slightly different CD drives were problematic, they would go to sleep and I'd have a dropout when moving from one disk to another as the motor wouldn't be fast enough to spin the disk again.

(and no, the original drives didn't have any custom DTS firmware in them, it's just that the software was sending them the appropriate commands to speed them down (you don't need 40x for DTS) and to keep them awake

Super-cool!

[Josh Jones]

Can you share the design for the brackets?

This is the bracket design I found. We did rotate it so it printed faceplate down, as I liked the texture of the printer mat.
https://cults3d.com/en/3d-model/tool...bracket-floppy

What's happening with the video output?

Older CGA cards have an artifact called CGA snow. I think it has something to do with memory paging. A VGA card with onboard memory won't have the artifact.

Josh

[Michael Zarits]

Excellent job and thanks for sharing that information!

[Marco Giustini]

Older CGA cards have an artifact called CGA snow. I think it has something to do with memory paging. A VGA card with onboard memory won't have the artifact.

Josh

Ah yes, the CGA snow effect! I've always used a VGA in them. Does the screen even work with a CGA card?

Anyways, it's impressive. I only have one 6D and I think I'd like to keep it "stock" but I am very much tempted to turn it into that!

[Josh Jones]

Does the screen even work with a CGA card?

Um, obviously. It's the card I had in the scrap bin. The better cards are a lot more expensive due to vintage gamer dweebs. There is a new production card using recovered VGA engine chips, but it was a lot more than I wanted to spend.

Josh

[Marco Giustini]

ahah I am one of those "vintage dweebs" but you should be able to get an ISA VGA for little. Sometimes it's just a matter of keeping an eye on ebay and/or local adverts.

CGA output is different from VGA, the signal is different, I'm surprised it just works. To test one of my EGA cards I had to make a level adaptor - and that was also not supposed to work. Still super-cool though!

[Josh Jones]

I am using the composite output to drive the monitor. There is no clearance behind the card for a connector, so I simply soldered an RCA pigtail across the jack connections.

Josh

[Marco Giustini]

ah that makes sense!

[Ryan Gallagher]

Definitely wins the award for most custom modded 6D. Great legacy revival project! I doubt I could get my folks to spend money on this, but having a viable backup to our XD10 is super tempting! We have a 6D in storage.

[Josh Jones]

For $150 you should be able to get a new power supply, adapter cable, the Zulu and a bay adapter. There are a lot of these guys laying around, and for many theaters this would be a simple, low cost backup option. The monitor and card are optional.

Josh