Seven Fiddy

I've been on the lookout for a certain piece of hardware for a little while, and just recently a good deal came up on eBay, so I jumped at it.

This here is the Roland S-750. It's a much older rack sampler than the Roland S-760 that I purchased previously.

And it is a chonky boi. It's 3u tall instead of 1u and a bit deeper than the S-760. What's somewhat amusing is that the boards inside don't really take up all that much more actual space than what would fit in a 1u case, but whatever, it is what it is.

Why did I want an S-750? Well I kind of didn't, actually. I wanted what it came with, which is this.

Wait, no, that's just a regular IEC power cord. I mean this.

This is the RC-100 remote controller, and it's actually worth more than I paid for the whole bundle together. So I essentially got a discounted RC-100 and a free S-750, which is kinda cool.

The RC-100 works with a number of Roland samplers, and in particular it works with the S-760, thus why I was interested in picking one up.

Anyway, fun will be had with the RC-100, but first let's see what we can do with the S-750. Inside we can see that it lacks the wave memory expansion, which is also something I'll be tinkering with later. It slots into the two grey connectors up at the top of the board.

But first, the volume knobs were looking a little misaligned and were binding somewhat, so let's see about fixing that.

The diagnosis of this issue is at least pretty simple.

This metal bracket is not supposed to be shaped like this. Let's fix that real quick.

And that's much better. Not perfectly straight, but it'll do. Back in the unit, things are looking much more aligned.

Though I do need to deal with one of the volume knobs, which managed to separate into two pieces while I was trying to pull it off the shaft.

A bit of not-so-super glue does the job just fine.

And the knobs are looking much better now.

So let's see what the RC-100 does. Just plug it in and hold the right buttons on the front panel to select it.

Except hmm, no dice. It's not powering on. Let's have a look at the jack board to see if it yields any clues.

It's the board on the right, there. Pulling it out we can see the problem pretty easily.

R35, a fusible resistor, has fused. This is not really a surprise given that it's on the +5v rail which supplies this port with power.

And as you can well imagine, with these male pins sticking out of the front of the unit, it's only a matter of time before something conductive comes in contact with them and lets all the magic smoke out of the fuse.

So a new pack of fuses is on the way, but in the meantime there's another problem: the sampler keeps auto-detecting a mouse, and the UI is scrolling uncontrollably when nothing is connected to this port.

After doing a fair bit of diagnosis, it looks like IC14 on the mainboard has fried. It's reading a very clean logic-high on the unconnected port as a logic-maybe, and interpreting that as (junk) data from a nonexistent mouse.

This is unfortunately a Roland-proprietary ASIC, and so no direct replacement is available unless I can find one to salvage from a parts unit. The other option would be to reverse engineer the ROM and OS to determine how it talks to this chip and then replace it with an FPGA. The chip doesn't do any particularly complicated tasks, it mostly just does the front panel matrix scanning, drives the LEDs, and acts as an IO expander.

Anyway, that project, assuming it ever happens, is pretty far down the to-do list so we'll see if I ever get around to it.

Oh and just in case you're wondering, the RC-100 works perfectly with my S-760.

The Other Weird One

The Boss RPS-10 isn't quite as weird as the Boss RSD-10 but it's up there. This one is also broken, too.

Was also broken, I guess. It's not broken anymore, but it's still weird.

The Great Fluffening Part 11

Well it's been a wild ride but it's finally come to a close.

It's time to nail up the last piece of strapping.

Feels good to be done this phase, but there's still one more thing I need to deal with before this project is fully complete, and that's installing the soffit vents.

They'll be going in these soffits here.

Most of the soffits will be getting two vents, but there's some uneven spacing so one of the soffits is only getting one. Let's see how the 2 inch auger bit does in drilling through these old chunks of Universal Wood.

Well it just eats right through them.

Though it's a bit of a sloppy eater.

Well holes are holes and, as we can see, these holes lead right into the space above the polyiso insulation panels.

Though this view won't last long, as they're getting plugged up with these round vents.

Which I pre-painted to match.

From the ground they basically disappear.

But they're up there, doing their thing.

And speaking of things down on the ground, I have a bit of sweeping to do.

Correction: I have a lot of sweeping to do.

And with that, the fluffening is complete.

A Sample Of My True Power

This is a Roland S-760, a sampler. We've previously discussed ROMplers like my Roland XV-5050, and this sampler is almost the same as that, except for the part where it doesn't come with any ROM samples. Instead, you load samples onto it either by recording them in from another instrument, or copying them onto the internal storage.

And by "internal storage" I mean external storage, because this thing only comes with a floppy drive and a SCSI port on the back. I've got a BlueSCSI on the way to handle the latter, but while I'm waiting for that I need to at least boot this thing up and check it out, which means I need a boot floppy.

But we don't do floppies around here, so let's get something more modern in that drive bay.

This is a Gotek, a floppy drive emulator. It's pretty much the defacto standard for replacing these old floppy drives, and it functions by storing floppy images on a USB thumb drive that you shove into the front. The problem with them is that the default firmware kind of sucks, so pretty much everyone loads FlashFloppy onto them instead.

But first, why are there two of them?

For reasons. These reasons have to do with these extra ports on the back of one of the units.

Make a mental note, we'll be getting back to this in a future blog post.

Anyway, if I'm gonna install this Gotek I'll need to dig in and scoop out the old floppy, so let's get inside.

And we've got a friendly message from the Roland engineers.

Oh good, it's world standard. Here I was worried it was only standard in Japan and perhaps East Asia.

Hmm, what are these boards at the back?

No, no, we're not getting distracted. Focus!

Removing the floppy drive is about as straightforward as it gets. Just two screws on each side and it's out.

The two brackets on the bottom get transferred over. The Gotek even includes self-tapping plastic screws, which is nice.

You know, I'm just realizing something. These ports on the back are arranged a bit differently.

I wonder if he power cable is gonna reach all the way over there to the four pins on the left?

That would appear to be a "no". But at least the floppy cable reaches with length to spare.

Well I guess I've got a side-project on my hands. Better knock out both at once while I'm at it.

Hmm that's interesting, this one is missing those extra boards... No, no, focus!

Look away if you're squeamish, things are gonna get a bit brutal.

We can rebuild it. Better, faster, and more importantly longer.

And I didn't even forget to put the heat-shrink on before soldering the final connections. Nice.

Rinse and repeat, and did I say the power cable was too short? I don't know why I would say that, it looks like it reaches just fine.

So it's time to crack open the thumb drive, which is packed in the most delightful frustration-free packaging imaginable.

I FEEL SO UNFRUSTRATED WITH THIS PACKAGING.

And I just need to plug it in and... oh wait right, I forgot the part about the default firmware sucking ass. Let's deal with that.

Usually one would do this using a USB A-to-A cable, which is a bit too much of a cursed device for me to willingly own, so we'll be doing this the slightly harder way, by connecting to the serial port hidden in this 9 pin header next to the power connector... which naturally doesn't come with header pins soldered in.

Skipping past the soldering montage, I can now jumper the device into DFU mode (which stands for Device Fucked Up Firmware Update) and run the flashing software on my wintendo, which definitely wasn't written in the same year this sampler was built and never updated since.

And done, it's running the FlashFloppy firmware. After copying the boot disk image over, easily downloaded from Roland's website (and renamed to 000.img so it's easy to find), things are looking promising.

Promising indeed.

And we're in like sin!

Now all I need to do is gently tweak the volume knob back straight and everything will be-

Well fuck.

At least the Goteks are installed, I guess.

And I suppose I have one more project on the todo list now.