napierzaza Posted May 25, 2007 Report Share Posted May 25, 2007 Considering that the MIDIBOX SID v2 will potentially have the ability to connect 2 SID modules to one core, I was wondering how this would be achieved? Would they share the same J2 connection? I'm planning on making a PCB with two of the modules together, and wanted to know what I should amalgamate and what I shouldn't. Quote Link to comment Share on other sites More sharing options...
Wilba Posted May 25, 2007 Report Share Posted May 25, 2007 You might want to refer to what I did on my 8xSID PCB:http://www.midibox.org/dokuwiki/doku.php?id=wilba_mb_6582You're right, they would share the same J2 connection, with separate SID:CS pin connections, essentially common data bus so SID registers can be set on either or both SIDs. It also then makes sense to use only two shift registers for each pair of SIDs, like what I did. You're welcome to copy as much as you like from my layout, it's as compact as you can get, and looks pretty neat with the common data bus arrangement. Quote Link to comment Share on other sites More sharing options...
Wilba Posted May 25, 2007 Report Share Posted May 25, 2007 Here's a close-up of the revised PCB: Quote Link to comment Share on other sites More sharing options...
napierzaza Posted May 25, 2007 Author Report Share Posted May 25, 2007 Whoa, That's some very cool stuff there, I'm going to copy as much as I can indeed! It's just a shame considering that it's in a different program than EAGLE, and also designed for people who can afford that sort of thing. I might as well tell you that your multi SID is really really amazing! Did you know it was posted on hackaday.com? Quote Link to comment Share on other sites More sharing options...
Wilba Posted May 25, 2007 Report Share Posted May 25, 2007 Yeah, I totally didn't expect that!As for EAGLE, I just used what I had available... and it was way too big for the free version of EAGLE. Quote Link to comment Share on other sites More sharing options...
napierzaza Posted May 25, 2007 Author Report Share Posted May 25, 2007 The more I look at this the more I realize it's particularly infeasible for a single sided board.It appears as if your version has a lot more connecting the two than just the j2. I suppose because you're only using 2 registers. I might just make a more simple version where there's two of Thorsten's model on one board. But I would like to optimize the registers as you have done. Quote Link to comment Share on other sites More sharing options...
napierzaza Posted May 26, 2007 Author Report Share Posted May 26, 2007 To anyone who is interested, here's my double SID board, all within a freeware EAGLE board. One problem I had was what to put on the pin right above the GND pin of the J2. It looks like on your board you actually attached the second SID's (the top one on mine) 8th pin to a funny pin on the PIC. What I mean by that is that you connected pin 8 of the SID to 27 of the PIC, which isn't available through that connector. Also I haven't totally checked it over so no guarantees as to whether it might work.mbhp_sid_v3+double.brd.zipmbhp_sid_v3+double.brd.zip Quote Link to comment Share on other sites More sharing options...
Wilba Posted May 26, 2007 Report Share Posted May 26, 2007 Yes, you'll need to use the "unused" pin on SID module's J2 port to connect to the PIC's pin 27 (Core J14). This will mean a bit of a change on the Core module PCB to connect PIC pin 27 to Core's J10 port.I must also strongly advice to separate digital and analog grounds on this module, i.e. connect the SID's ground to the same ground as the audio buffers, audio output and 7809 or 7812 ground pin. Use a separate ground connection for 74HC595 (connected to ground on the J2 port).A separate 5V connection to the SID would also be a good idea, i.e. connect the 74HC595 5V to J2 port, and have a separate 5V connection to the SID, which you can connect to J2 port if you want, or connect with separate wiring to the PSU. This will minimize digital noise on the 5V supply coming out the audio output. Quote Link to comment Share on other sites More sharing options...
napierzaza Posted May 26, 2007 Author Report Share Posted May 26, 2007 Do I have to modify the core anymore than a jumper? Can that pin (above the GND) still remain attached to the J2 pin as it is presently? Or do I have to just leave it disconnected and make a new jumper pin to the new pin described? Quote Link to comment Share on other sites More sharing options...
Wilba Posted May 27, 2007 Report Share Posted May 27, 2007 I don't know what you mean exactly...As far as I know, Core:J10:SC is not being used by the SID module.So, cut the track between Core:J10:SC and PIC pin 22, and connect Core:J10:SC to PIC pin 27 with wire. Then on the Dual-SID module, that pin goes to second SID's CS pin.Other people with two SID modules can also do the same thing, and modify the second SID module so the SID:J2:SC connects to SID's CS pin, and break track between SID:J2:SO and SID's CS pin. Quote Link to comment Share on other sites More sharing options...
dj3nk Posted May 27, 2007 Report Share Posted May 27, 2007 very good idea because i want to build a multi sid :) thanks for the nice work ! Quote Link to comment Share on other sites More sharing options...
napierzaza Posted May 29, 2007 Author Report Share Posted May 29, 2007 Yes, that's exactly what I meant, I was wondering whether I would have to cut the pin that it goes to on the core and reroute it, or whether I can just jumper it and have bother connected. It's just that I forsee that I'll be using a smash board for this (for the core), making it difficult to remove any pins of sort. I guess I'll have to punch up a proto board. Quote Link to comment Share on other sites More sharing options...
napierzaza Posted May 31, 2007 Author Report Share Posted May 31, 2007 If anyone is interested here is the final version of the board as per Wilba's suggestions, plus several fixes which were previously unseen.mbhp_sid_Double.brd.zipmbhp_sid_Double.brd.zip Quote Link to comment Share on other sites More sharing options...
NorthernLightX Posted June 1, 2007 Report Share Posted June 1, 2007 You could easily relay some of the tracks of the upper SID to make 4 bridges unnecessary. Same trick could be done for the SID on the bottem but you have less board space here. I think it's possible to move th power section to the middle of the board and thus create enough space for the rewiring of the bottom SID - moving the power to the middle also removes one bridge, maybe even two.Are you planning to have your design etched? I can help you to improve on the design if you would like. Quote Link to comment Share on other sites More sharing options...
napierzaza Posted June 2, 2007 Author Report Share Posted June 2, 2007 Thanks for the suggestions, for some reason I didn't really realize that or thought it was better to make way too many jumpers. I have incorporated your design suggestions. Please tell me what you think.I suppose I will be trying to figure out how to etch PCBs for this one. I actually have gathered the two 6851s so other than PCB I have all the diifficult stuff.mbhp_sid_Double.brd.zipmbhp_sid_Double.brd.zip Quote Link to comment Share on other sites More sharing options...
napierzaza Posted June 4, 2007 Author Report Share Posted June 4, 2007 For little good reason I made a new one that is a little wider and a little shorter. This seems a little better to me conceptually, I guess I should not have followed Wilba's so closely as now it's much closer to the origal positioning.As far as I can tell it would work just as well as the other one, but it's just a different foorprint.mbhp_sid_DoubleALT.brd 2.zipmbhp_sid_DoubleALT.brd 2.zip Quote Link to comment Share on other sites More sharing options...
NorthernLightX Posted June 4, 2007 Report Share Posted June 4, 2007 I like it. If I would have laid it out I would probably have paid some extra attention to the track width and paths, because I'm an annoying perfectionist, but like this it will probably work as good. If you're having it etched I would be interested in a pcb as well for testing mods for my (still conceptual) Midibox SID. Quote Link to comment Share on other sites More sharing options...
napierzaza Posted June 5, 2007 Author Report Share Posted June 5, 2007 I'd certainly be open to suggestions about the track widths. I tried to make them as thick as they could really muster within the available space. If there's some rule or suggestions you have about that I'm all ears.Well I certainly hope this PCB works out well enough too! We'll see if I can ever muster this project to go further than concept :-\ Quote Link to comment Share on other sites More sharing options...
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