AndrewMartens

Honestly I probably won't use it for anything else. I'm already putting my other "it was great at the time and seems bad to cannibalize now" ISA soundcard (AVM Apex) in my only remaining ISA machine. It's just wrong, since the Tropez was probably a better card - but it only cost me $3 at a surplus computer parts store, whereas I think I spent about $250 on the Apex back in the late 1990s... Most likely I'll end up stealing the parts off it to make another MIDIbox FM board in the long run. But at least I'll feel bad about doing it ;) And besides, it's the only one that has the 14.38whatever MHz oscillator onboard!

... when you're cleaning. I knew that once-upon-a-time I had ordered four Core boards and two SID boards. In order to make the OPL3 module, I still needed to order a couple of boards. But today when I was organizing some drawers, I found: - two OPL3 R1 PCBs - a complete DINx4 R2 kit - three panel-mount MIDI jacks - three 24LC256 ICs :D Well, I was amazed by this, but on the plus side that means I have a less ordering to do in the future! That's good news for my wallet! I still have a spare MIDI jack, not to mention another three 24LC256es (and two 24LC512s, thanks Microchip ;D !) It may be time to start populating a few more Core boards, and one of those OPL3s. Come to think of it, someone had setup the hot air rework station at my company this week. Maybe I'll have to learn how to use it, and remove some YMF262s and YAC512s in the process... ;) Looking at my box of soundcard, I've got four of each. But it just seems wrong to cannibalize that nice old TB Tropez ISA card, with its 68k processor, wavefront IC, and maxed out with a nice set of 30-pin SIMMs.

When doing a voltage check on my board, I thought I damaged the wipers in the socket of my CORE in just this way. I sucked it up, stuffed the PIC in anyways. Lo and behold, it works! For my next project I'm going to use the good quality machined-pin sockets so that I never need to worry about this again :-)

Once you get the knack of it, doing it with needlenose pliers isn't *that* bad. That said, I've probably done hundreds of pins that way, so I'm used to it by now. If I had crimpers, I'd use them for sure, but I'd rather spend my money on parts instead of tools ;D

Sample-and-hold is your friend here. In order to make the necessary number of CVs, you could probably get by with one 12-bit resistor ladder, and a dozen S&H circuits. I think you should be able to make that with three TL074s (one opamp per S&H), though you'll need an opamp buffer on the output of your R2R ladder as well. And a bunch of transistors (to gate the signal to the necessary opamp), capacitors, etc. It's the approach that I'm using on my revised wavetable synth in order to control the analog filter (!) circuitry. Not as accurate as using a bunch of DACs, but a LOT cheaper, and far easier to acquire parts for.

Here's the sequence I used: - soldered a 2x7 header to the LCD, and two individual pins for the anode and cathode - crimped an IDC16 (ie, 2x8 connector) to the 16-pin ribbon cable - separated, stripped, and tinned each of the 16 wires on the other end - wrote down the colours of each wire next to the pins on the LCD datasheet (printed out) - tinned each of the pins attached to the LCD - tacked each wire of the ribbon cable to the appropriate pin on the LCD - test! It's not the best method, but I didn't feel like trying to get each individual wire into the right spot on an IDC14 crimp connector. Maybe I'll try that one next time. Somehow I still managed to write down the colours wrong on the first attempt - I managed to reverse Vcc and Gnd (whoops!) - but luckily didn't blow up the LCD.

I have heard that to clean the conductive carbon pads (Alesis style ones, like one typically has in a remote control, etc.), that you use two products. (1) alcohol to clean the oxidized contacts on the PCB, make them all nice and shiny again, and (2) a chemical product to put new conductive material on the pads. For the second one, I have heard that Chemtronics CW2605 or CW2610 works well - http://www.chemtronics.com/products/product.asp?id=32 Unfortunately I was unable to get this product shipped to Canada, so I ordered CaiKote 44 (a similar product, I believe) from my local shop - http://www.rpelectronics.com/Default.asp?Main=/English/OnlineCat.asp?Menu=/English/Content/Categories/CatM_85.asp%26Detail=/English/Content/Items/K-CK44-2G.asp I haven't had the time yet to use the stuff, but it sounds like it should work well. Hmmm, the shelf life is about to expire, I'd better get off my butt. Hopefully I can do my MMT-8 and HR-16 with one container.

Come on, I just bought an MMT-8 a year or two ago! All I need is some free time for my "expandable flash storage" mod - I'm already halfway through deciphering and commenting the disassembled ROM from it :D I'm not about to bring a computer to a gig!

If you're low on space, just design the four-SID section so that you could create a daughtercard variant of it, and just make a small stackable header that connects to it. Make sure the tall caps are in a different part of the board, and you're good to go!

TK's Midi troubleshooting page is a good link, which he originally posted. I had this exact problem on my MB SID - it turned out that I swapped the outside pins on my MIDI In connection. I had printed out the schematic, soldered the wires, checked it. Plugged in the cable header, double-checked it. Connected it to my MIDI interface, nothing. Checked it a third time against the schematic and realized that I had the MIDI plug upside-down. The MIDI Out I had wired just fine (which is why the PC was receiving the upload requests every few seconds) but the MIDI In was wrong.

Definitely a good idea to use the connectors - I'm going to do that for my next unit. I didn't have any on hand, so I just soldered the wires to the headers. It works, but it then becomes a pain to mount everything in the case because it's all attached together in a big rat's nest (and that was just for a SID CS_A!).

If these were actual potentiometers, one could connect the wiper (which also would go to the AIN module) to an opamp (set to a gain of 1, just acting as a buffer), and run the output of that through an LED and resistor. Using a digital encoder would require a MIOS-based solution, as covered above.

Thanks, TK! I'm quite happy with it not sending CC at all - I'm just using it as a quick way to switch through the filter settings on it. As a simple way to enable the filter on [123E], it works great. I just removed all the code that I had written, and made the changes that you suggested. Then I added another change so that dedicated button presses restore the old menu settings afterwards - if I've got a button for it, I don't need it jumping into the menu. That was an easy matter of just commenting out three lines in cs_menu.inc. Now I just need to edit the text that I wrote, take some more pictures, and post it up on the Wiki sometime this week...

Oh, that reminds me! I just noticed this the other day - http://www.sparkfun.com/commerce/product_info.php?products_id=7955 It's a module that uses SD cards to load/read data, and handles all the overhead of the FAT filesystem. I have no idea whether it's any good, but it should be useful for applications that want to do simple file manipulations without all the hassle of dealing with FAT itself.

Probably, yes. There's a converter available here: http://sourceforge.net/project/showfiles.php?group_id=116852 I just downloaded it the other day, but I haven't had a chance to load up any of the patches yet into my MIDIbox SID. Undoubtedly there's someone here who has already used it and can say whether or not it works well.

SD and MMC cards also use the SPI protocol, so you could optionally use that as well (depending on the pins you have available on the PIC, I suppose). Encoding / decoding the FAT filesystem is the real overhead in the whole thing. If you're using the PIC to store and read all the data and the card is never going into a PC, then you should just be able to use it as a large flat memory space and the implementation becomes much easier.

I thought that I could puzzle this one out myself, but I'm having trouble determining how to access the CS_SID_FILTER_CHANNELS register directly. At this point I've been experimenting for about an hour (and I quickly perused the forums and wiki) but haven't figured this one out yet. And yes, I'm planning on documenting this modification in the wiki! ;D What I'm attempting to do is have a single button that cycles through the Filter Channels [123] and the external input. Cycling through the first three channels is the default behaviour, and I have my button mapped correctly so that's working. I can even figure out how to also set toggle the external input bit, that's not so bad either. The problem I'm having is trying to determine when the three filter channel bits are all set to 1, and then toggle the external bit. I assumed that (due to the cs_menu_led.inc) the relevant bits should be ANDLW'd with 0x0E first (ie, 0000123E), then I'm using the SUBLW to subtract for comparison. You can see where I'm trying to access the bits below, but I'm a bit confused how to get at the register directly without going through the whole menu structure. Ideally I'm planning on bypassing the menu setup entirely (should be easy once I've got the register address / map figured out). The following code is taken from my cs_menu_buttons.inc: [pre]CS_MENU_BUTTON_Fil_Sel ;; do nothing if button has been depressed IFSET MIOS_PARAMETER2, 0, return ;; check if the Filter setting is maxed out yet call CS_MENU_MS_GetSIDBase movlw 0x80 andwf FSR0L, F movlw CS_SID_FILTER_CHANNELS movf PLUSW0, W ; is that the right way to read the register? andlw 0x0E ; mask the CS_SID_FILTER_CHANNELS register sublw 0x0E ; subtract for comparison btfss STATUS, Z ; if zero bit is set, skip next line goto CS_MENU_BUTTON_Fil_Sel_2 ;; obviously the Filter setting is maxed out, so first ;; we want to toggle the EXT filter setting movlw 0x05 ; cursor pos movwf MIOS_PARAMETER1 movlw 0x00 ; page offset (maybe?) movwf MIOS_PARAMETER2 movlw CS_MENU_FIL ; menu structure call CS_MENU_ButtonToggle ; we're just turning EXT on or off ; and we're using a call because we ; want to return back here and then inc the filter CS_MENU_BUTTON_Fil_Sel_2 ;; else increment Filter setting movlw 0x00 ; cursor pos movwf MIOS_PARAMETER1 movlw 0x00 ; page offset movwf MIOS_PARAMETER2 movlw CS_MENU_FIL ; menu structure goto CS_MENU_ButtonInc [/pre] I don't need a full solution here for my plan, just a way to load up the CS_SID_FILTER_CHANNELS into W. I can take it from there... ;)

Hey TK! That's my plan - once I finish putting it all together, I'm going to transfer a number of these notes to the Wiki. There's just one more mod that I need to finish up (probably tonight) before I complete my panel and mount everything. It's just a simple filter button and four LEDs (for OSC1-3 and the external input) to enable the filters without going through the menus. It's a standard part of CS_C, I know, but I just figured I'd hack it into my last remaining input on my DINX1 module, and document the process. Slap that up on the Wiki, and then people can hopefully figure out how to map a few buttons themselves. Not that it's particularly difficult - everything is already either on the forums, the schematics, or documented in the code. You've done a fantastic job making it easy to use and modify, Thorsten, and you should be commended on this more often. MIOS and the SID application are excellent! ;D

It's rather unfortunate that they wouldn't stand behind their FAQ. I've been considering using BatchPCB - http://www.batchpcb.com/index.php - they seem okay, and the price is definitely right (at least for small runs or individual pieces of small boards). It's just the waiting time that leaves something to be desired. Thanks for putting up those reviews on your site - at some point in the next few months I'm going to need to get some PCBs fabricated!

Another evening, another update. Today's progress: The Joystick Thanks to this thread - http://www.midibox.org/forum/index.php?topic=5708.0 - and also this one - http://69.56.171.55/~midibox/forum/index.php?topic=3375.0 - I have my filter hooked up and it seems to be working fine. It sounds like the cutoff is around 120~121, and the resonance seems to be working well enough, despite its limited resolution. Currently it's wired with a 100nF cap between +5V and GND on each of the 10k potentiometers, and it controls without any jitter at all (that I can hear). I'm still not sure about my filter caps, as the "full resonance" sound is rather gritty and distorted. I like it, but I'm just not sure if the caps are correct. Guess I'll have to go back and listen to a bunch of other SID samples to figure it out. I managed to dig up the Digikey label for the caps that I have - turns out they're polyester film, whereas I thought I had aimed for polystyrene originally. That'll be an ongoing investigation, but they'll be easy enough to swap - and I have a set of ceramic caps also available if need be. The Case Coming along so far, I did a mock-up with cardboard, transferred it to the aluminum plate and started drilling. Of course there's always going to be some error, and the drill holes ended up being spaced out a bit too far due to drill slippage. I'm up to my largest bit size already and I need to enlarge the pushbuttons just a bit, and the joystick isn't even close. I'm leaving the LCD until last, because even with a dremel-clone it's likely to annoy me. Assuming I can get it finished tomorrow, I'll slap a coat or two of primer on it. Then perhaps I'll paint it a nice soft blue like our kitchen (using left over house paint, of course!) or possibly a soft off-white, add some hand-lettering, and then a clearcoat over top.

There's at least two ways to do it: (1) measure everything with a digital caliper and plot it on the computer, then print out a copy to ensure your plan lines up with your hardware. Or you can do the less professional method, like I'm going to do, which is: (2) cut out a cardboard dummy panel from a cereal box, line up your interface components (buttons on the PCBs, LCD, joystick, LEDs, etc.), and use a fine marker/pencil to trace around the outside. Cut out the openings with an exacto knife. Match up the components, and hope you did it right. If not, repeat - it's just cardboard at this point. Once everything is in place, mark the screwholes for your PCBs. Cut those out (or drill through into a piece of wood, whatever), and then mount everything to the cardboard with screws. Yes, somewhat time-consuming, but if you've just got the one panel, you don't want to screw it up. If you're happy with it, then remove all the components, and mark all the cuts/holes on your nice panel. Grab your drill / dremel / whatever and go to town! At least, that's my plan. Hopefully it will work... I just bought a Hammond enclosure from Digikey that seemed to fit my needs. There's a number of threads on the forums about good enclosure choices, but I'm not aware of any that offer free samples.

I highly recommend it. Just make sure you think about your mounting points for the PCBs when you do it. In the half-cased picture, you can just make out the drill hole at either end of the 4-button PCB; hopefully that will be enough. I was originally going to put the EXEC button on that same PCB, but I found there was a lot of torque applied to the encoder (which was just going to be panel mounted), and I didn't want it coming loose all the time. Put those two on their own PCB, since they're on the same side of the DIN module, and the four mounting holes PLUS the encoder nut should be more than adequate. This was originally going to be a dual-SID, but then I realized (a) the case was too small, and (b) I only had one more button, and the series had been discontinued. Fortunately the awesome VST-control exists, so I'll just build a headless SID as my second unit.

Introduction About two years ago now I had bought my SID and CORE boards, and at the time I had populated one of each, checked VDD and VSS, and then I had to put them away (moving, getting married, family fun, buying a house, moving, more family troubles, etc.). But I finally started getting keen about the MIDIbox family of products again, so it seemed like a good time to "nerd it up", as I like to say. Things I Did Wrong: I had wired up the LCD correctly, until I made a few hasty mistakes on my rough pinout sketch and reversed VDD and VSS. Whoops! This one was pretty obvious, since it browned-out my bench supply. Once I took a look and realized that red went to ground and black went to VDD, it was just a quick fix. reversed the wires on my MIDI OUT. Had a sketch, triple-checked it, and still did it backwards! somehow in fixing the first two problems, I managed to burn out one of the MIDI outputs on my MOTU MicroLite (now it appears to be a 5x4 interface). NOT HAPPY. Next time I'll throw in a crappy PCI soundcard to use. I still have no idea how I did this, since I had disconnected the MIDI cables during troubleshooting. when creating the DINx1 on a veroboard, I managed to connect the +5V line in series with the capacitor instead of in parallel with it. Easily traced, easily fixed. I had to rebuild a CS_A HEX file twice, as I hadn't properly cleared out all of the parameters from the original "full" 6581 ASM file the first time. The symptom was that the buttons and encoder behaved very oddly, bringing up odd pages of parameters, jumping around, etc. The encoder was backwards initially, which made it a bit jumpy for some reason. I reversed the pins and it's smoother, though still jumps just a bit sometimes when I'm trying to go slowly. using an R2 SID board and an R3 core, I foolishly connected SC to SC on the connection. After finding that I had a silent SID (and having fixed all the above issues, and I had checked all the voltages before connecting the SID), I double-checked the schematics. Sure enough, there we go - just connect MD to SC, and it works! installing the power plug in the middle of the back of the case was rather silly, and I should have just put it off to one side. Oh well, that's what I get for not bothering to redo the cabling that was two short to reach from any other position... Things I Did Right: checking pins with a multimeter *before* plugging in ICs. That made me reasonably sure that I hadn't blown anything up. pluggable headers are very nice, and I did use some for the back panel hardware. But I just didn't have any 4- and 5-pin ones available, so I went with the direct-wired route for those connections. The latter is faster, but it gets somewhat cumbersome even with just four boards joined together. getting a good soldering iron. Fortunately (?) my Radio Shack soldering iron burnt out this weekend, so I got a nice Weller WTCPT soldering station. It made all the detail work so much easier, especially connecting the ribbon cable to the SIL and DIL headers! checking the forums and the website. There's a lot of great information out there, and a few resources that I didn't have to quite resort to (ie the SID interconnection test). Every time I got a bit perplexed, an hour or so looking at the website and the forums usually did the trick and helped me find what I needed. while reversing the encoder, I also removed the oscillator from the SID_V2 board and wired up the PWM connection. After all, that's what my original design from five or six years ago (when I started designing my SIDGroove synthesizer) had called for. No more gate glitches. Things Still TBD: connect analog joystick to control filter cutoff / PWM / whatever check the filter capacitors that I used in the SID. I'm honestly not 100% what it sounds like with good caps and what it sounds like with less-good caps. I put them in there two years ago, and I'm not sure if I used mylar or styrene at all. Could be something else. create front panel (rough in with cardboard, then drill/cut panel) paint panel, attach interface components make some music! And now, PICTURES! DINx1 + Bankstick (awaiting ICs, top): DINx1 + Bankstick (bottom - next time use macro mode on the camera): A working Core module... I felt pretty good once this was working: The case is drilled, and the standoffs are ready to use. They turned out to be just the right height: All wired up, and no place to go (next time, make the audio cable shorter; at least it's shielded): And a nice in-situ glamour shot of everybody's favourite: More pics to come once I've got the front panel all wired up!

Yeah, I half-expected at the time that the Radio Shack guy was an idiot, but hoped that he wasn't. But here's the beauty of it: using the WTCPT is several times faster than fighting with the crappy RadioShack garbage that I was using. I managed to finish all my soldering on Sunday as a result. There were a lot of narrow areas where I needed that fine conical tip (that was another key bit, getting the right tip) and it was just so fast. Plus it heated up quickly, delivered consistent heat, etc. 100% A++ would buy again! ;) Another happy convert from a crappy iron to a good iron!

Ahh, Radio Shack soldering irons. I had a trusty 15/30W switchable that served me for about ten years now. Yesterday I went looking to see if I could get a new, pointier conical tip for the thing (instead of the rather blunt one that came with it). In the store, they had a replacement tip of the original style, but also a nice pointy one for their 15W soldering pencil. So I asked the manager, "Should this 15W tip work in my [points to other soldering iron] slightly different iron, as long as I have it set on 15W?" "It should!" he says. Good enough for me, so I spend my two bucks and go home. Swap in the tip, plug in the iron, and SPARK! Put the original tip back in, and it doesn't heat up. Take the whole thing apart, the wires inside have been vaporized. Go back to the store, tell the manager he's a bloody idiot, and head to a different electronics store for a new Weller iron. I was going to get a WP25, but I figured with the amount of soldering I plan to do over my lifetime, getting something better would probably be the best idea, so I splurged and got a WTCPT instead. Woo!