davotron

My first MBSID has 8 buttons and an encoder with a push button under the shaft - function buttons 1 - 5, page up/page down, shift and then the encoder is used for menu up/down and to enter paramater values, the button in the encoder is the "enter" button so to speak.

It may be worth looking at the Core32 and using the OSC protocol over ethernet... or even ASID this way. Core32 has a USB port also. I'm sure midi would work though, it just feels a bit clunky to have all those CC params, less slick as it were than a more direct and faster software control.

That case looks awesome joewhat, keep us posted! but what communication protocol are you going to use between the PC and the MBSID? this is the question!

Ah yes, ASID.. cheers, will have a look at this. I love the idea of having a tracker that has exclusive MBSID parameters though as the thing is so damn powerful compared to existing SID based synthersisers. Of course you could just use something like Renoise and just set up three tracks for the three SID oscillators and assign CC parameters to all the MBSID params..

Hi Guys, This kinda goes back to my previous direct SID control question (I realised since it is quite possible to hook up a SID to a parallel port or serial interface and control it that way, if one was so inclined!). How cool would it be to have a MBSID parameter specific tracker (with three columns, one for each oscillator) that could talk to a core32 and SID directly over OSC or a direct USB protocol... failing this has anyone had any joy with a program like Renoise in playing SID music with a whole load of midi events? I find renoise is complicated.. cool but complicated. It almost defeats what made a tracker so good: that one could sequence SID music and play it "directly" on the machine (much like other trackers on the Atari ST and Amiga 500).

It's just a buffering principle, you could use the very simple bipolar transistor (essentially a "current buffer" in my opinion) or a simple op amp buffer (voltage follower), or voltage amplifier. Opto couplers would work, but there are a few more bits involved, i.e. the opto couple would be used to drive another transistor stage I would imagine (think of an old opto compressor). A pair of 74HC04 inverters one into the other makes a nice simple non inverting JFET buffer, as long as the single doesn't get clipped and it's biased properly. Just take the audio out of the SID into the simple transistor circuit for the easy option... you could in theory take several buffered feeds from the SID output before it's actually loaded down too much.

Ah yeah, of course! I have been looking indeed. Just trying to generalise the point of why bother talking to the SID directly when MIOS and the SID firmware do it so easily and so well, and give you tons of awesome functionality. This made me thought of something else: is the sine wave generated from a table of values for a full period, i.e. sin(2?)? Could someone, in due course, if they were so inclined, edit the software and add the functionality of storing other wavetables somewhere and use these? Like the sounds of the early WT synths? But Reaktor? 24 voices! awesome! sounds great!

I was thinking back more to the days of the C64 command line and POKE to address a certain reg and then give it some value to make sounds, kinda bypassing any "hardware" i/o, Although I did think this editor is most useful. But why I hear you say? I though it would be cool to be able to enter a command on the MIOS studio debug terminal, similar to "POKE" to access the SID registers directly, so a small tracker program could be built to do the same etc to make cool sequenced tracks up. Although there's actually no need for this as you could just send all the stuff as normal midi control data and have the same effect (as obviously MIOS and the SID app do it already).

Not sure if this has been discussed on here previously: on the much useful debug terminal front, I've realised this could open up direct manipulation of the SID registers quite easily which opens up a whole bunch of possibilities. How cool would it be to have a SID specific audio tracker program running on your PC etc.

Thanks for that, if I can help out I shall! I've done the odd bit of assembler, C/C++ and BASIC over the years, quite like the usage of the linux style terminal shell and associated commands. I haven't had a chance to look at the new MIOS studio beta; what level of i/o has already been implemented in the debugging terminal? How cool would it be to have small debugging commands to show MIDI i/o activity (like a midi ox terminal), button presses etc all in real time! (although I guess this is very possible with the current OS with the LCD display) I was thinking more a small file system set of commands, so you could edit front panel buttons, patches, midi/ethernet set up etc directly from a terminal. How is MIOS32 structured (trying not to sound too daft here!): do you have a form of "file system" hierarchy with a "root" then within there directories where progs/apps/commands are executed from and files are stored? I suppose with MIOS8 it is very low level and more embedded so to speak, in the sense that you compile a program with your major hardware configuration set up, and it essentially just runs therein, all in one enclosed program with limited debugging i/o (unless a specific app was written to test i/o of course!)

I think I need to walk before I can run! I'm definitely interested though, certainly an eye opener knowing this exists now. I'll have a bit more of a play when I've got my first midibox SID finished - it works, just need to sort out a nice enclosure for it etc. I like the idea of terminal control via midi though, I guess it is essentially just RS232. Thinking of going for a stereo version next, but it will most certainly have an STM32 core. Had considered using an atmega 32 ARM a couple of years ago to control a SID chip, but the STM32 definitely has a few more plus points.

cool, that's awesome, I must have a play with one of these things!

I was just had a thought having worked on various embedded systems where I used to work: how nice would it be to have a serial port on the STM32 core that you could hook up to a PC comms terminal (or via ethernet to a telnet connection?!) that could be used to access a "higher level" version of MIOS. Instead of editing config files, then compiling/assembling etc, config files could be edited from a terminal within the file structure of the OS whilst "online" so to speak - could be really useful for frontpanel debugging, editing patch files/ensembles etc I was playing with a very simple low level command line version of embedded linux once, thought how cool would that be.. I don't know anything about FreeRTOS, is there any implementation of this in the pipeline? Sorry if its been talked about before or implemented etc! It's a shame there is no version of an embedded RiscOS... David

Aha, thank you, I wondered about some way of banking the patches into 2 lots of 64, I shall get on the case. Thanks, David

Howdy.. I had a couple of spare 24LC256 EEPROMS lying around, so thought I'd try to use them as banksticks for my MB SID, running midibox_sid_v2_0_rc28 to give me 64k instead buying some 512's. I assumed if I hooked them up in parallel to the core, but made one "hardware address" A0 and the other A1 I would get 2 x 32k giving me a full 128 slots available to store patches (ensembles aside for now). This doesn't seem to work though, they are both formatted correctly though. I get the first 64 patches uploaded, then 65 - 128 say "no bankstick"; if I swap the addresses around, make the one that was A0 A1 and A1 A0 I get the first 64 saying "empty" (which is correct as nothing was uploaded to this other chip) and the next 64 saying "no bankstick". This proves the connections of the memories to the core must be right - I just have a little address jumper to either ground or tie address pin 1 (physical pin 1) of the memory to +5v, so the memory at A0 is seen but the other isn't. Am I missing something? It's probably easier to just get some 512k memories ordered! but thats no fun, so I thought I'd run it past you guys to see if I've missed something fundamental!

I got my hands on a 6582, measured an audio output DC resistance of about 16K... powered it up and got my 4.8V DC at the audio output pin and hence a beautiful singing 1kHz tone! So there we are folks, a dead SID indeed - and a good test if people do have problems. Regarding R2; doesn't seem to make a massive difference leaving it in or out on 6582's/8580's, but I'm leaving it in as I am unsure of the internals of the thing. Datasheet says "open source", yet there is no pull down resistor in the diagram there where there is for the 6581, yet commodore left it in the C64 PCB diagrams up to latest rev.... ??? can't hurt to leave it in really, just as I say if there is an internal resistor you could give yourself more output by omitting it, hence more awesome sounds!

Cheers stryd, I'm sort of mega sure the SID is a dead SID, do you have any 8580 MBSIDS up and running at the moment? Stick a meter between ground and audio out and see how many volts there are. I did a bit of work, R2 isn't massively important on 8580 SIDS, the later rev MOS datasheet omits it, but the later C64 drawings leave it in! When it is in place it just drops the output impedance of the audio output by a bit. Be interesting to see how it would change the sound of a working MB SID though, I guess you get more signal if you take it out.

Hello guys, after starting to build a MidiboxSID V2, with a rev 3 PCB some months ago I had other commitments and I put a halt on it. I have picked it all up again from where I left off. My problem is that I seem to have a very small output signal from the audio out pin; I have the test tone app running, and my SID is getting 4.99V Vcc, and 8.97V Vdd and is properly grounded 'n all. If I hook up the audio out to a hifi amp I can hear the test tone but very very quietly with amp gain up full (I tried with a mixer mic amp, plus a seperate SSL mic amp, loads of things and I can only just hear it with stacks and stacks of gain [+ all the noise of course]). If I lift the audio output pin away from the IC socket, carefully, so it's effectively isolated from the output circuit of the MBSID design, and AC couple the pin with a cap to the amp input, the signal has a bit more power so my first problem is that the output transistor stage is doing something strange by loading the signal down. I can see how it provides protection for the output of the SID, but I'd have thought with the collector up at 9V and a small signal on the base, there would be some degree of voltage gain of the signal appearing across the 1K res from emitter to ground? I could easily be wrong though, as I often am! I take it the 470pF provides some LP filtering for supersonic stuff that you don't really want appearing there? Unless I have a faulty BC547 I cannot see how this stage is giving me headaches! It is built correctly, I followed it all round with an ohmeter, though signal at the base of the NPN is OK, at the emitter is quieter and a lot noisier, although this transistor checks out on a tester OK with an Hfe of about 250, pretty typical of a BC547. At first I couldn't see how this circuit would work i.e. how the transistor is biased, but I guess it is so by the DC output of the SID; if there isn't one, or too small a voltage, it won't work, this is a possibility of what is going on here. *update*: since I'm using an 8580 device, I believe it has an internal pull down and thus doesn't have an open drain output, so is R2 really needed? The DC offset of the 6581 audio output is about 6V as opposed to the 4.75V of the 8580; both have a p-p output of about 3V I THINK.. The thing I really wanted to know was what should the resistance be between SID audio output and ground? If I measure the chip out of circuit, I get about 2.4K, with chip in circuit this goes in parallel with the 1K pull down so you end up with about 690R, I wondered if that is a sign that my SID 8580 is dead? Or is there an internal pull down of 2.4k etc? The original datasheet states you should measure 4.75V DC between the output and ground, I get more like 800 mV ish. I don't suppose there is any other test to find out if the little fella is well and truly dead, except put the C64 back together and load up a game with some bangin' tunes on! If anyone has any ideas great stuff, if nay, no problemo, I thought I'd ask :) It's doing my head in! Sorry for the lengthy-ness, I'm trying to cover all aspects to get to the fix. David_

I compiled gputils 0.13.6 on OS X (as there is no compiled package as of yet) and installed and it works just fine, if anyone else was looking to assemble code for p18f4685's using gpasm on OS X.

Ah that old conventions chesnut... the number of long winded conversations we used to have at ssl over this one, ha! I totally agree, so why does that diagram have "SO" to "SO" for the core to one of the SID's if I was following that? And on my Din the actual serial output pin has no screened label.

I found the R5 Din board has a similar thing; the "SO" pin of J1 ("SO" being screened on the PCB) isn't actually connected to the serial out of the shift reg - the one adjacent to it is that has no screened text.

I don't 'geddit? I'm probably being completely stupid. There is no "MD" silk screened on the V3 board, and the "SC" pin seems to go to where the "MD" pin connects to according to Thorstens (that link) drawing for the V3 PCB layout I have or are you referring to the "SO" to J14 for the right SID? Edit: I actually have a V4 PCB, I got from smashtv, I can't seem to find the layout data for this though.

Hey, Snyderman I'd consider getting an LCD display too, it has certainly helped me begin this project, as long as it complies with the Hitachi HD44780 specification

After running the interconnections app. I discovered I definitely have a connection problem between CORE and SID! (which, incidentally means I might not have an audio output problem.. but doesn't explain the weak tone I was getting yet) I'll go over it properly tonight. Cheers nILS Podewski for that quick software build guide, I was concentrating on doing it in Mac OS X but that sorted me right out for now! Update: It seems that the silk screened "SC" on my SID V3 board actually goes to the "MD" pin of J10 on the CORE; this is the signal from pin 28 (RD5/PSP5/P1B) of the PIC to the SCLK storage reg clock input of the 595's, have I missed a change log somewhere that I couldn't find? It has cured it anyway!

Ah yeah of course, this I understand, and it's this is what makes it interesting! Yep got a tidy regulated bench supply in the end. The SID gets Vdd @ pin 28 of around +8.9 to 9V, current limit at 1500mA so there's plenty of power there if it so requires; Vcc around 4.8V. David