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It’s Alive!

Posted by Tom Virostek on November 21, 2009
Posted in: DSS-1. Tagged: . Leave a Comment

Well, three sales so far. One kit, one board mod, and one full DSS-1 mod.

Bought another unit off of eBay, unfortunately the seller didn’t pack it very well, and one of the black keys got broken. Good thing I have a parts unit.

V 3.99 has a bunch of fixes in it for USB saving and loading, also adds directory sorting and navigation improvements. Also discovered, while building up more boards, that the byte counter pin on the CPLD needs to be disconnected from the ribbon header, or the signal reflections will corrupt the count.

I’m going to start selling my other DSS-1’s on eBay. Time to start making room for the next project.

Oh yeah, a big thank you to Glen Stegner for his awesome review of the project on his site!

http://www.glenstegner.com/dss1

Loose Ends

Posted by Tom Virostek on October 29, 2009
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I’m finally going on vacation! It’s only for a few days but it couldn’t come at a better time.

Jim continues to squash the odd bug here and there in the OS (currently 3.94 as of this entry). Portamento has been added, as has the ability to update the OS from a USB storage device. I’ve started compiling libraries onto flash disks, and am going to include them with the purchase of the kits (while supplies last!).

I’ve documented the install procedure and am in the process of writing the manual. I’ll probably get it done this weekend.

Picked up another used DSS-1. Someone had really bitched it trying to get it open. One side of the case was gouged where someone stuck a screwdriver trying to pry the lid up when the screw stripped. I found the reason why they wanted to open it up, a nice puddle of dried up soda right next to the power supply. Luckily it didn’t get in the electronics.

Also, I have lowered the prices on the LCD and combo drive options, as I’ve found lower priced options for both. The new LCD is yellow-green, not as flashy as the blue-white but still much better than no backlight at all!!

I’m going to start selling off my modded DSS-1’s. I think the software is at a point where it is pretty solid, and updating will be a breeze thanks to the flash ROM.

USB Storage Finalized

Posted by Tom Virostek on September 13, 2009
Posted in: DSS-1, Update, USB. Tagged: . Leave a Comment

Finally, after months of debugging, the USB storage part of the kit is functional. Jim has done fantastic work of getting it all up and going. We managed to squeeze all the needed functionality into a 72-macrocell CPLD. The USB transfer speed is very fast, utilizing DMA directly from USB to the wave RAM.

I’m posting the news on the Yahoo! groups DSS-1 user group, but first I’m going to offer the existing kits (at a reduced price) to those of you who have been patiently waiting.

DSS-1 Mod Update 2

Posted by Tom Virostek on May 7, 2009
Posted in: DSS-1, Update. Tagged: , . Leave a Comment

Well, it turns out that the daughterboard had a LOT more problems than I would have liked. On the hardware side, solder bridges and shorts took a lot of time to track down. Also, similar to the main board, the main CPU’s ASTB (address strobe) signal needs to be buffered, as it’s not latching the address bits properly on its own.

Also a couple of dumb errors with the CPLD. I had several versions of the project, and the version I used had the pin placement wrong. Also had the decode logic wrong for the Flash ROM.

The good news is that Jim is working with the new hardware and I think we may see results in a couple of weeks.

Aside from this project, I’ve made some progress on the new revision of the main CPU board. All of the TTL logic is being replaced with two medium-sized CPLD’s and it will have a newer floppy controller and the VNC1L USB controller integrated.

DSS-1 Mod Update

Posted by Tom Virostek on April 11, 2009
Posted in: DSS-1, Update. Tagged: , . Leave a Comment

So, I’ve finally gotten the USB daughterboard to boot up. Took a few weekends and some time on the logic analyzer. It doesn’t have the new code needed to run the USB module, but it does have the new expanded memory map and additional RAM. Note to self: next time a design has 10 mil track spacing and power planes, spend the extra money and get a solder mask. I spent most of the debugging time tracking down micrscopic solder bridges.

I sent a test board off to the programmer, Jim, and he sent me a test build of the software. It isn’t quite working yet, so I have to put it back on the logic analyzer. This time, I spent some money and got a proper socket probe for the flash memory, instead of soldering a bunch of test points on the PCB.

Also Jim wondered if it might be possible to upgrade the DAC to 16 bits. In theory it’s possible, since the RAM is now 16 bits wide, but the latches are only 12 bits wide and would have to be replaced. Also the software would have to be changed to allow the synthesis functions to work on full 16 bit words. And unlike the modifications so far, this would actually change (improve?) the sound of the instrument. I’m going to see how the USB mod pans out…then I’ll see if it’s worthwhile doing.

Post Install

Posted by Tom Virostek on March 9, 2009
Posted in: Update. Leave a Comment

I just finished a grueling 8 week installation at my workplace. We gutted two of our studios and installed two brand new Euphonix System 5 Fusion consoles. Today is the first day they go online.

I got two more sets of boards back from manufacturing. The first adds support for flash memory, more RAM, and USB to the DSS-1 retrofit board. Can’t really test it out until the new software is written. Also got back the 16 Meg memory boards. I discovered much to my dismay that the DRAM chips I am using are not 5V tolerant, nor is the 3.3V side of the level translator IC I am using for the data bus. Back to the drawing board!

Hopefully I’ll get the add-on board for the DSS-1 built and sent to the programmer for testing this week.

Holding Pattern

Posted by Tom Virostek on January 15, 2009
Posted in: Update. Leave a Comment

I’ve started work on the SY-99 page.

Things will be on hold for a bit. We are installing a new Euphonix System 5 at my work, and the de-install of the old console is like hacking through the jungle with a machete. Instead of a machete I have my Greenlee cable shears.

If anyone wants a dual engine Neve DFC, I can point them in the right direction…

Finally…An Update

Posted by Tom Virostek on January 14, 2009
Posted in: Update. Leave a Comment

Well…better late than never I guess.

Response to the DSS-1 expansion project has been mixed, to say the least. Most people feel it costs too much money. Many people don’t realize that the project isn’t just a memory board that drops in place, it’s a whole new CPU board AND memory board. Not too much I can do about that, as Korg really under-powered the instrument when it was designed. Although in terms of 1986 tech, it probably didn’t make financial sense to make it more powerful. Korg tried to correct the shortcomings of the DSS-1 with the DSM-1, adding expanded memory, SCSI, and improved (?) operating system, but left out some of the good bits like the filter resonance control and DDL’s.
The DSS-MSRK addressed many of the DSS-1’s shortcomings but for various reasons never became widespread.

Another misconception is that I have ‘redesigned’ the original expansion kit. I haven’t. I guess you could say I’ve ‘reorganized and repackaged’ the original design, but I haven’t (and couldn’t) make changes to the software since I don’t have the source code nor the time to disassemble, analyze, and rebuild the software for a project that might interest 50 people. I did make an exact clone of the original DSS-MSRK PCB, but without the custom Korg chip to put on it, it’s not much use. The main ideo of this project was to simplify the original design and make it easier for an end user to install.

For those of you who haven’t been on the DSS-1 Yahoo user’s group, the biggest news has been the software updates to the project. I was contacted by Jim Babb, who was one of the original designers of the DSS-MSRK expansion kit. We had exchanged a few emails, and it turned out that he still had the original 1987 source code for the DSS-MSRK!!! Not only did he agree to send me the last version that was developed (which added support for 1.44Mb floppy drives), but agreed to further develop the software and add user-requested features (thanks Jim!!).

At this point the software (V3.3) supports HD floppy drives, but also improves the SCSI spec (now supporting up to 1GB drives), improves support for SCSI to CF drives, improves the diagnostic mode, and allows you to reassign the data entry and tuning sliders to various voice parameters. The sofware will now support a 16 MB memory board that will be going into production in a few weeks.

Of course this is only the beginning….stay tuned.