Mr modnaR

thanks for taking the time to explain that. very informative. ;D ahh yes, simple when you know, how embarrassing! :-[

I'm hopeless at electronics, so please bear with me. i'm having trouble understanding the following things with this psu: 1. what is the reason for all the capacitors on the psu, i understand you need one or two for smoothing out the a.c. but why so many? 2. the 220 on the led circuit, is that 220ohms or 200kohms or what? i assume 220ohms, but thought i'd ask. 3. i can see a 7805 outputting 5V and a 7812 outputting 12V, but on TK's optimised psu, there's a 7809 (which i'm assuming puts out 9V because that's what you use on a sid module for the 8580 SID) outputting 14V??? i just don't get it. i can understand that something like a resistor knocks voltage down to a value that is relative to the input voltage, but i thought voltage regulators put out what they're designed for - a set voltage - what ever their input voltage is (up to a certain limit of course). any explanations are welcome. thanks.

ok, cheers mate.

@Altitude: if you didn't mount the large cap C5, why does it say that that cap should still be there in the c64 psu pdf? ???

on my master core i've mounted: PIC Opto coupler all resistors all caps (except C4 and C5) Q1 T1 (is this needed if i power my backlight directly from the power supply?) J2 (for power) J10 (for SID) J15 (for LCD) J4 (for bankstick) J8+J9 (for DIN+DOUT) J11 pins MO and VS on my slave core, i've mounted: PIC all resistors all caps (except C4 and C5) Q1 J2 (for power) J10 (for SID) J11 pins MI and VS now i need to know is that all correct? do all the resistors need to go on. (i know some don't on the slaves, but i'm not sure which ones. cheers people.

i was going to leave off the large and small caps, but wasn't absolutely sure they weren't needed, but they'll come off now, thanks for the tip.

cool yes i will do that. cheers tk

hello all, i found nebula's question relating to what is not needed on slave cores/sids, but iwas wondering if everything was mentioned in that thread? basically, what components do not need to be mounted on the slaves. thanks in advance. :)

ahh i see. thanks for the tip.

i'll try this out. yes i understand this, i just couldn't understand why they would be different if they both are compatible with the hitachi standard. i guess it's just the other pins that have to comply, not the backlight. ah well, i'll just have to switch them round.

i measured the output to the LCD though (B+ and B-) and there was no change in voltage. strange.

hello all, i've just returned from my holiday to find a lovely package waiting to be torn open and the contents constructed! ;D now, the problem is: i've made up the first core, and it works fine, i've uploaded MIOS and the SID application, however, i cannot adjust the backlight with the left hand pot. the other adjusts the contrast just fine. what can i have done wrong? i have checked the pins of the pot with my multi meter, but there is no voltage any direction. any ideas? thanks. also an unrelated (i think) problem, i have an lcd from SmashTV which works fine (apart from the backlight being on full power). however i also have an LCD from crystalfontz, but that backlight does not work at all. i applied the backlight voltage in reverse, and it worked! is this unrelated to the adjustment problem, or could it be related? cheers in advance.

i have 3 6581R4ARs and a 'normal' 6581 to go in my soon to be MBSIDx4. as soon as it's built i'll post something up here.

Wow! Partially sighted electrophiles all over the world rejoice! cool project!

out of curiosity, why did you include it in that case?

cool, so you've built this design then? how quiet is it? can it be compared to the c64 psu? also, what was the point of having a separate output for the LCD backlight? sorry, i'm new to all this complicated stuff! :-[

hi, just looked through your flikr pages: very impressive stuff! about the PSU you'#ve made though, you say you updated the design because you weren't getting enough power? is the design in this thread the updated one? cheers

to me that seems cheap, but we do get raped regularly by the government here. >:(

yes that's right. it's up to you mate, i don't know what these screens that come from hong kong are like, for the price i guess it's worth a try. ???

ok, not sure who supplies out there. you could try ordering from www.mini-itx.com or www.linitx.com they both have lcds for sale.

the reason they bump up the shipping ,and make the price of the item low, is to lower their ebay charges. as for where to get one, where do you live?

ok, thanks for your help thorsten! i think i'll venture down the newbie path with regards to the power supply and the audio in i guess. there's always the next MBSID!

that is correct. the c64 PSU outputs 5VDC and 9VAC

ahh, i think i understand now that the SID module can take AC or DC (sorry didn't read properly!) i though PC PSUs are designed to give very stable voltages, due to the sensitive nature of the CPU etc.? ok, thanks for explaining this to me. is it possible to make a connection that's shorted when no jack is present in the socket, and open when there is one? or would it be easier to just have some shorted jacks which could be placed in the input sockets when they're not in use? or is all this speculation/brainstorming not worth it. i mean what can you actually do to inputted audio? is it just the filter, or are there other plans up your sleeve? thank you for your replys thorsten, much appreciated!

i have looked though a few pages of threads, and done some searches too, if the following questions have definitely been answered before, don't hesitate to tell me, thanks! 1. i'm having trouble understanding exactly what voltages are needed to run 4xCOREs and 4xSIDs. the optimised psu pdf states 14VDC and 5VDC, yet elsewhere it's stated 15VAC is needed for the SID modules. ??? if only 14VDC and 5VDC are needed, would it be possible to power the whole lot with a PC PSU? really i'd like just a standard 'kettle' lead going to the synth. ;D 2. i don't understand why the audio ins must be shorted as in the optimised psu pdf. i can see they'd possibly add additional noise, but does it mean that they are useless? i would like to throw a few things through the sid, you know, just to see what happens! ;D thanks in advance!