Jurbo Posted February 13, 2005 Report Share Posted February 13, 2005 Just happened to take a closer look at the PSU of my 1541-II disk drive (PSU type number: DV-5128UP), and it says on the case, that the transformer outputs 5V DC and 12 V DC. What do you think - could this unit be used for powering the MBSID? Of course, a new optimized power circuit would have to be designed, but how about it? The voltages would be just right for a Core and SID 6581.Not that this matters to me personally, as I use my C64 PSU with the optimized circuit, but this might actually help somebody out there. :) Quote Link to comment Share on other sites More sharing options...
doc Posted February 13, 2005 Report Share Posted February 13, 2005 Hi,I remember those psu's ( I gave mine away 20 years ago or so ...)The circuit would be more easy than the C64 PSU because of the DC for both voltages.Can you find out how much current the psu delivers ?If this would be enough to drive the MB you just need a 9V regulator for the SID (or leave 12V for the other SID)greets Doc Quote Link to comment Share on other sites More sharing options...
Jurbo Posted February 13, 2005 Author Report Share Posted February 13, 2005 Oh yes, the amperage is printed on the PSU: 5 V DC 700 mA and 12 V DC 500 mA.I suppose this is enough for an MBSID system, right?Anyway, I hope someone will benefit from this information. Quote Link to comment Share on other sites More sharing options...
doc Posted February 13, 2005 Report Share Posted February 13, 2005 Ok,the 12V (or 9V with regulator) is no problem !The 5V is also OK with a 20*2 LCD. If you you use a 40X2 with backlight and the SID Step C (a lot of LEDs) then it could be that the 700mA are not enough Power. But it's worth a try !!greetsDOC Quote Link to comment Share on other sites More sharing options...
th0mas Posted March 25, 2006 Report Share Posted March 25, 2006 I also have one of these powersupplies, and I just realized it after already building the optimized power circuit for the standard C64 power supply :( (not a big deal, anyways..)Can I just plug this right in? the Pinout is +5v/+12v/GND (other pin is NC). I'm using a 6581 and currently my SID board has a 12v regulator in it, which I'm assuming would end up doing nothing (but is it okay to leave it there?)The reason I ask is that someone said:"Of course, a new optimized power circuit would have to be designed, but how about it?"Is this necessary?Cheers,TomEdit: The readings from the PSU are giving me: 12.08 for the 12v DC, 5.58 for the 5v DC. Is 5.58 too hot? Quote Link to comment Share on other sites More sharing options...
NorthernLightX Posted March 25, 2006 Report Share Posted March 25, 2006 Hi,if the PSU you're using already has regulators on board for 5V and 12V I wouldn't stuff te regulators on the boards (unless you're using 8580 SIDs, then you should stuff 7509 or 75L09 on the SID boards). The 5,58V is fine for the Core, 12,08 is also fine for the 6581 SID, or to feed into the 7809/78L09.The following text is a statement of which I do not know if it is 100% correct, read my topic on the Midibox PSU for details and/or a reply from someone who can confirm the statement.Remember that if your PSU is not regulated, the voltages you measure now could be up to 20% higher if you plug in the PSU at an other location! In that case, it might be wise to DO stuff the regultaors on the Core and the SID, even if you use the 6581.Cheers, Alex. Quote Link to comment Share on other sites More sharing options...
th0mas Posted March 25, 2006 Report Share Posted March 25, 2006 Sweet! Thanks for the reply, I'm about to try it out! :) Quote Link to comment Share on other sites More sharing options...
th0mas Posted March 26, 2006 Report Share Posted March 26, 2006 I just measured my voltages, and..the SID module is being given 12v. I have a 12v regulator stuffed on the board currently. Pin 14 to Pin 28 of the IC1 socket, however, is only 9V!Do I have to short out the regulator?Edit: shorted out the regulator, now I get 11.78V.Cheers, (and thanks everyone for their help!!!)TomEDIT::: IT WORKS!!)#($!@)(#!@#K!M@#L@!K#M YAAAHOOOOO!!! Quote Link to comment Share on other sites More sharing options...
stryd_one Posted March 27, 2006 Report Share Posted March 27, 2006 Brilliant! I have like 5 of these drives sitting around collecting dust...Thanks guys!Could you update the wiki with your findings? I'f you're not sure what to do, just PM me and I'll take care of it for you :) Quote Link to comment Share on other sites More sharing options...
th0mas Posted March 27, 2006 Report Share Posted March 27, 2006 Sure, I can do that, I'll poke around for the best place to do so.Edit: Actually, I should investigate it's usage a bit more first, see if anyone has any suggestions and make sure it _is_ an appropriate power supply.My 6581 SID operates pretty weird. It often does things such as, OSC's randomly drop out of notes, filtering seems to be very inaccurate (doesn't really do what it should in any mode, sometimes it does but doesn't always), etc. OSC's sometimes play the wrong frequency (and hitting the note a second time, the OSC will play the right frequency). Basically every time I play a note there's a certain percentage of the sound that is random. If I apply the filter to all the oscillators, then often the sound simply cuts itself off.Does this sound like problems induced by a bad power supply? (keeping in mind that I *did* potentially roll over my SID chip with a chair, so I could just have a half-busted SID at this point ;) )FWIW, I love it anyways, it's unpredictable-ness makes for a far more entertaining synth than anything I could buy.Cheers,Tom Quote Link to comment Share on other sites More sharing options...
stryd_one Posted March 27, 2006 Report Share Posted March 27, 2006 Actually that sounds like a dodgy SID (assuming you've checked the PCB's etc), have you tried another one? Quote Link to comment Share on other sites More sharing options...
th0mas Posted March 27, 2006 Report Share Posted March 27, 2006 No, but that's what I figured.I like it, so I don't think I'll bother with a new SID unless one falls into my hands for cheap :) Quote Link to comment Share on other sites More sharing options...
stryd_one Posted March 28, 2006 Report Share Posted March 28, 2006 You could always program a realtime random modulation feature into the MBSID :) Quote Link to comment Share on other sites More sharing options...
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