Hi,
here's a mod I'm doing at the moment. I wouldn't usually have posted this here at all, but it's Gryzors MiST, the MiST is becoming more interesting for us since the CPC Core is being developed and I'm not a member of any ST Forum. So here it is...
The general plan looks like this:
- Take MiST out of original case and fit it into an Atari ST external drive. ie: an SF354 in this case.
Goals:
- All connections and power switch on the back.
- SD Card accessable from floppy slit.
- All buttons / LEDs on front, but as discretely as possible.
- Try to keep SF looking as original as possible.
Here's the SF354 before I started:
[attach=2]
(Great cases because they are much more resistant to yellowing than beige coloured ones :) )
Today I stripped out the insides first. I've installed a "blank PCB" onto the mounting holes of the drive, this allows me to mount things as I want without having to cut holes all over the outer case. This is what it looks like so far:
[attach=3]
The Board is fully coated in copper on the bottom, so I will connect this to GND later to shield the board. Next up I will add another PCB for the new SD slot which will be raised to the height of the floppy slit. Unfortunately, quite a bit of the slit detail is part of the drive and not the casing. So I had to remove this and transfer it to the case.
[attach=4]
For the three buttons I'm going to try to split the original wide eject button into three parts to actuate buttons behind it. Not sure if this will work, but it's worth a try. No plan for the LEDs yet. Suggestions welcome.
Bryce.
Quote from: Bryce on 14:57, 22 March 15
No plan for the LEDs yet. Suggestions welcome.
Look there are 3 leds.
One power
One for FPGA
ONe for mass storage access
What about using a RGB led in place of the disk access LED ?
You may need to tune the current limiting resistor (and hope volateg is enough to drive the blue led ?)
Yes, that's one of the things that I was considering. Unfortunately, the cover for the original LED is dark red, so I can't put an RGB LED behind it :(
My current idea was to use the original LED position for mass-storage access. Illuminate the complete slot blue for power and FPGA, not sure? Does the user ever really need to see this?
Bryce.
Ohhh yeah! Time to get making those decals myself to put on it... :) Cheers mate!
I just didn't understand what you meant by "Unfortunately, quite a bit of the slit detail is part of the drive and not the casing. So I had to remove this and transfer it to the case."?
As for the LEDs, ah we had discussed this and you had told me about the RGB LED but not about the cover being red... Too bad, but the other solutions sound cooler :D All three LEDs are useful to diagnose what's going on - well, the power LED is not more useful than other power LEDs, but if you did that whole-slot illumination it would look utterly cool...
Really nice solution, mounting a blank PCB at the bottom :)
Quote from: Gryzor on 17:12, 22 March 15
I just didn't understand what you meant by "Unfortunately, quite a bit of the slit detail is part of the drive and not the casing. So I had to remove this and transfer it to the case."?
If you look at the last picture in the first thread. That big plastic bit in the middle was part of the drive, not the case. I had to remove it from the drive and now need to find a way to connect it to the outer case.
LEDs: New idea. Storage LED is the drive LED. Power LED makes the slot glow blue, but FPGA LED changes the glow to a different colour?
Bryce.
Oh, I see. Why not just a couple of drops of glue? Or am I missing some implication?
Yup, good idea about the LEDs, especially since it means you won't have to drill another hole that will necessarily be different than the existing one :) Only negative I can think of is if the LED is not powerful enough...
Quote from: Gryzor on 09:00, 23 March 15
Oh, I see. Why not just a couple of drops of glue? Or am I missing some implication?
Yup, good idea about the LEDs, especially since it means you won't have to drill another hole that will necessarily be different than the existing one :) Only negative I can think of is if the LED is not powerful enough...
Yes, I can just glue it, it was just the hassle of having to dismantle the drive etc that I was moaning about :D
I have some plexiglas light-pipes that I will experiment with and see how much light I can get. I am thinking of having a plexiglas tube across the slot with a blue LED at one end and a red LED at the other end. That way it would glow blue but turn red on FPGA activity. I want it to look cool. :)
Bryce.
P.s. I've decided to buy one of these to extend the SD card slot: SD card extension Cable PRICE INCLUDES VAT | eBay (http://www.ebay.de/itm/SD-card-extension-Cable-PRICE-INCLUDES-VAT-/111623168708) . My first plan was to remove the original slot and put it on a new PCB. I'd prefer not to modify the MiST PCB at all for warranty/repair reasons, but the buttons/LEDs don't have a header, so some modification is unavoidable. I'm not that happy with the length of the extension (SDcard connections should be kept to a minimum), so I will shorten it to the required length.
Of *course* it must look cool! Maybe we can get some sound feedback and have them light up in rythm, a-la Chinese gadgets :D
Ah, the extension then, hope it works. If it does it's a great solution indeed... Do you plan on filling the space around the SD slot in any way?
Just realised that the extension probably won't work. It doesn't pass on the "Card inserted" signals, so the MiST would always think a card was inserted which might mess up the software. Looks like I'm back to removing the original slot.
If the light-pipe works, then there will be clear plexiglas filling the rest of the slot. Otherwise I will fill it with black plastic.
Bryce.
Not sure the board actually does anything with the signal, and in any case I don't ever turn it on without a card in it so I'm unsure as to how much of a problem that would be... Do you want me to ask the dev anything specific?
Ps ew, black plastic :D
Black matt plastic, but deep inside, just so that you don't see inside it.
I'll take a look at the PCB tonight and see if the card-present signals are being used. If not, I'll order the extension.
Bryce.
Ah, deep, that's better :)
Ok, crossing fingers :)
Looks like the MiST uses the card-present signals, they are definitely wired back to the FPGA. I think it's better if I extend the socket from the PCB.
Bryce.
Hm. But, what problems could that present? As I said, you can't run it without a card present, so even if software gets confused or whatever, what's the harm?
I would second Gryzor opinion.
1st - the FPGA core is on the SD card, so there is no point starting the MiST without it.
2nd - the software should detect that there is no card anyway by timeout when initialising the communication to the card
True, maybe I'll order one of those extension cards and give it a go. I wasn't aware that hot-swapping isn't really possible anyway.
Bryce.
Edit: Extension card ordered.
(Sao Tome and Principe's power supply might be more of a problem to the unit than an absent SD card :D )
Not only is hot-swapping not really possible, but it's without any merit either; you've got a huge card containing everything, only reason you'd swap it is if you downloaded something and wanted to load it after powering up the unit... So I guess all's well with it (assuming it works!).
By the way, how are you planning to extend the VGA and USB after all?
Ahhh, I have my own Cocoa bean powered generator here on the island :D
I have panel mounting USB and VGA sockets that will be mounted on the rear and have small extension cables that plug directly into the original sockets. For the power I intend to add the same socket as the CPC 5V uses. That way you can power the MiST using your CPC PSU.
Bryce.
Sounds very cool :) The cocoa-bean-powered generator, I mean.
Just to make sure I asked Till, his reply was he can see no problem with always telling the board a card is present :)
Thanks. As soon as the extension arrives I'll have a try. I still haven't powered it up even once? ::) I'm afraid I would waste days on it :D
Bryce.
Ah, but that's a shame really... You should probably do some thorough "testing" once it's done!
(but hey, how do you know it even works? :D )
I don't at the moment, but I will fully test it before a soldering iron ever touches it. I always do.
Bryce.
Ah, there goes the modding :D
Still waiting for the SD Card thingy to arrive, so I thought I'd start on the back of the case where I intend mounting (if possible) all ports. As you can see, at the moment it has the regular ST round connectors (in/out) etc, so this all has to go. There's a ridge that I thought might be useful for holding the new back panel, but it's only 2mm deep and the plastic I have is 3mm thick, so that has to go too.
[attach=2]
[attach=3]
Then I cut a piece of plastic to fill the space. I'll secure this with two screws through the back when it's finished.
[attach=4]
Now time to make the hole. It's just roughly cut at the moment as I might need to make it bigger depending on the space I need for the connectors.
[attach=5]
And here it is with the panel fitted.
[attach=6]
The plastic isn't exactly the same colour, but it's at the back and will be filled with ports anyway, so it's not a big problem. At this stage I realised that other than the USB and VGA ports I don't have the others, so I'll need to order those now. The SD card will probably arrive in the meantime, so I can start on that while I'm waiting for them to arrive...
Bryce.
I always cringe when I have to cut something old, and I realised I cringe when watching others do it, too :D
Yeah, no problem about the colour, not visible at all really so it doesn't matter...
Thanks for the update :)
The plastic on the SF354 case is rather soft, so no chance of the dreaded "crack that goes across the whole case", but you still need to be careful on old plastic and definitely don't do it in a very cold environment. I usually heat the plastic a bit before I start. All finished now anyway, other than the button mod, there's no other cutting needed on the old plastic.
Bryce.
Heh, reminded me of the time at army camp when we were trying to repurpose a plastic water tank using hacksaws... At minus 10. That was a fun day :D
Sorry but that just too neat for a hardware engineer to have done unaided - where's all the hotglue ? ;D ;D
In time, in time :D
Although I own a hotglue gun, I use it extremely seldom. A last resort in my opinion.
Bryce.
Gesendet von meinem Motorola DynaTEC 8000X mit Tapatalk 2.
Yes, yes, what about the mod? :D (j/k of course)
So... Back home, time to take a look at the SD Card extension that arrived in the post. At on end the flat cable goes neatly into a fake SD card. The other end is soldered directly to the PCB, which is unfortunately just big enough for the socket with no mounting holes >:( .
[attach=2]
[attach=3]
The FFC is 520mm long! I'm pretty sure this would cause issues, especially on high-speed cards, so without thinking any further I cut the FFC in the middle, bringing it down to about 240mm and soldered it back onto the PCB. The FFC is a rubbery type of plastic which was a pain to remove. I won't be getting any awards for neatness, but it works fine.
[attach=4]
[attach=5]
Next up I made a new PCB at the level required for SD Card, the buttons will also be mounted on the lower side of this PCB. It's mounted on 4 posts which makes it solid enough to withstand a lifetime of button presses and card insertion.
[attach=6]
That's it for today. Just some further questions for Gryzor:
- Do you want / need a power switch on the case?
- Do you want / need the RS232 or Midi sockets?
Bryce.
Still no hotglue in sight :)
"which is unfortunately just big enough for the socket with no mounting holes"? You mean "fortunately" or I missed something?
Great touch with that separate "daughterboard" there, looks like you're building a whole new machine :D
Unfortunately yes, it does need a power button/switch. Normally you could do without it I guess, just pulling the plug off the wall, but if you're doing config testing and you need to reboot several times while making sure memory is completely erased you need the switch... No preference as to its location though (but naturally the front is more practical).
I was thinking of becoming the next Jean Michel Jarre so yes, I'll need the midi socket, plus - ah, no, no need for any of that fancy stuff :)
What? "That's it for today"? But it's not done yet!
No, I meant unfortunately. The SD Card slot on the flat cable needs to be secured to the "daughterboard" - with mounting holes it would be a lot easier. But it has neither holes, nor space to make any, so I'm going to have to come up with something else.
Power switch is no problem, but to keep things looking original I'd prefer to put it at the back, but easily accessable (small toggle switch).
There can never be another Jean Michel Jarre, he is one of a kind :)
No, it's not done yet and I have to order quite a few parts for it this week to continue, so it'll be a few days before I continue.
Bryce.
I didn't say "JMJ", I said the *next* JMJ!
Ah, I understand now, about the slot mounting. Erm... Superglue?
Yeah, switch at the back would be just as good, you're right in keeping as much as possible out of sight.
You haven't ordered them already? But I see my cheques were cashed weeks ago!
Maybe hotglue :D NOT, I always try to make things "service-able", so nothing glued.
What cheques???
Bryce.
One cheque actually, the one for 200 euros and a not "for parts"? Ring a bell?
Well, I understand your point of view, but what would be serviceable" in a SD-card slot and a blank pcb?
Quote from: Gryzor on 20:09, 07 April 15
One cheque actually, the one for 200 euros and a not "for parts"? Ring a bell?
Well, I understand your point of view, but what would be serviceable" in a SD-card slot and a blank pcb?
€200!!??
Well the solder joints under that card PCB would no longer be accessable if it was glued. Unlikely that they will fail, but I like to be careful.
Bryce.
It's your mod, head down to the local Sao Tome hardware store and see if they got anything :D
Moving swiftly along (NOT). This weekend and today I finally managed to get back to the MiST mod after fixing a massive amount of other retro stuff (sorry repairs always take priority). Anyway, this time I decided to work on the backplane again. First off some serious amount plastic drilling. It's quite a tight fit because there's a lot to fit on there. Starting from left to right we have the VGA port above, below is the power switch and power input. I used the same sized socket and polarity as the CPC so that you can use your CPC PSU to power it. In the middle are the two Joystick ports and on the right are two USB ports.
Drilled:
[attach=2]
Fitted:
[attach=3]
Installed:
[attach=4]
Still some minor finishing to do, but I'm pretty pleased with the result so far. Next up I'll install the SD Card slot and then start on the buttons and lighting.
Bryce.
Ohh this looks professional and tidy!!!
Just one question, why not use a dual USB port, wouldn't it be easier?
So excited to see it going forward (technically speaking, it's not working as it is now, so shouldn't it count as a repaid?)
If you can find dual panel mounted USB ports then send me a link. I'll buy a pile of them.
"A repaid"?
Bryce.
I can see lots of photos on Google but it's too early to follow them, but what wrong with this one for instance?
1 5ft 50cm Dual USB 2 0 A Female Panel Mount to Motherboard 10 Pin Header Cable (http://www.ebay.com/itm/1-5ft-50cm-dual-USB-2-0-A-female-panel-mount-to-motherboard-10-Pin-header-cable-/331296735224)
[EDIT] Wait, we already had this conversation, didn't we? :D
"repaid" - as in "repair", but with a flourish.
Wow, thanks. I've been looking for these for quite a while. Can't remember having this conversation before, but then again I'm getting old.
Bryce.
Edit: Very strange. The article says "Ships Worldwide" but then says "Doesn't ship to Germany"??
Huh, I'm pretty sure we got into a discussion about mounted USB sockets because we were also talking about the various types, but it probably wasn't about dual ones.
You're welcome, it's not always someone can point you to something you were not aware off :D
If you want I can buy some for you (wow that's a reversal!).
T
PS free shipping for me, too!
Hmmm, just realised I put the wrong polarity VGA socket on the backplane. The Female one needs to be here :)
Bryce.
Oooh good thing you realised before I fried it :D
Highly unlikely. You'd just have two male connectors and not be able to connect a screen.
Bryce.
...and somehow I missed the "VGA" part in your post, I thought it was about the power plug, go figure.
My fault for saying polarity when I actually meant gender.
Bryce.
Of course it's your fault, didn't say it was mine :D
Hmmmm, just realised (while swapping the VGA socket), that I also haven't included an Audio Out socket... Oops, some changes need to be made. ::)
Bryce.
Ooops :D
Just remember to put the Mist board inside, ok? :D
Quote from: Gryzor on 12:30, 01 May 15
Ooops :D
Just remember to put the Mist board inside, ok? :D
MiST Board?? What MiST Boa... Shit! That's why I still have so much spare space inside!!
Bryce.
Well, feel free to go full steam ahead with your original plan to fill it with gold bullion :)
Quote from: Gryzor on 21:47, 01 May 15
Well, feel free to go full steam ahead with your original plan to fill it with gold bullion :)
Na, that idea died after I checked the postage costs to Greece.
Bryce.
Duuuude, I told you, that's on me! Don't worry!!!
Been a while since I got anything done on this, due to repair jobs, but this (and last) weekend I managed to get a few hours in. First off I've fixed up the rear panel: Wrong VGA Socket and sound output missing.
[attach=2]
The fancy cut-out around the sound socket isn't so that it looks good, it's so that I have as much surface as possible to bond the plastic when I install it :)
Next up I made the "harness". This is a job I hate doing, fiddly wire soldering that takes ages. Done:
[attach=3]
I've used connectors on every connection instead of soldering anything, which means that the top cover of the SF354 can be completely removed if needed. The buttons / LEDs will need to be soldered, but they are mounted in the bottom half of the case.
I still need to add the power socket. The MiST offers two options. Power through USB or a standard power socket. I still have to add the socket and according to the schematics, I need to move the 0R bridge from R2 to R1 to divert the power tracks to the correct socket. I've already removed the black gunk to get at R1. For the power switch I've just wired the new rear panel switch in series, so the PCB switch doesn't get touched, it's just left ON all the time.
[attach=4]
Bryce.
Ohhhh yeah. Every time you post here I drop everything I'm doing to check it out, and I'm never disapointed :)
Does the VGA ribbon need to be so long?
The VGA needs to loop over the MiST PCB, so yes. It could possibly be 20mm shorter, but I didn't want to add any unnecessary strain to the cable. Pin 9 is not connected by the way.
Bryce.
Ahhh I see, I wouldn't imagine it needs to be *that* long...
It looks long because the other fly-leads are pretty short, but it's not that long in reality. I'll take a picture of it all connected and show you.
Bryce.
Edit: Quick (blurred) picture of the panel connected. As you can see, the cable isn't much longer than it needs to be. The SD expansion will need to fold over this connection too.
Ah there's a fold too. Indeed it looks just perfect. And actually it seems the SF is a near-perfect fit for the MiST after all, who would've thought, it looked pretty big at first!
This is...a big power plug! :D
Quote from: Gryzor on 06:18, 26 May 15
This is...a big power plug! :D
It's the exact same size[NB]It's not far away :)[/NB], voltage and polarity as the CPC power plug so that you only need one PSU :)
Bryce.
Oh yes, I know, I meant the plug though, not the socket. Or is that not a plug, the one sitting on top of the board's center
Yes, that's the power plug. The footprint on the MiST PCB is for the socket to this connector, so I don't have a choice in what connector I use.
Bryce.
Easily the most waste of space then :D
I could leave off the cover like I did on the USB connectors, but I don't like to leave the main power wires uncovered.
Bryce.
Ah yes, that's good :D
Unfortunately this weekend wasn't a hardware weekend, life just got in the way, but I did get to do a few small jobs on the MiST Mod. I moved bridge from R2 to R1 and installed the power socket:
[attach=2]
I also mounted the SD slot expansion on the riser board. Sorry all you hotglue fans, I went for a rather unconventional method. The slot is soldered in place using wires. This means it's easily removed in needed. I will post a personal apology on the "We love hotglue Forum" (I'm sure there's one somewhere):
[attach=3]
Now all that's left to do is sort out the buttons and LEDs. The buttons are the hard part. I need to be 100% sure that my method will work before I cut the eject button in three, so I'm taking my time with the planning.
Bryce.
Life got in the way? What life? :D
The wire/solder solution looks ace indeed! Even if with use the solder breaks and it starts moving I can fix it myself...
What might the issue be with the buttons? I had the impression it was a simple case, or I'm missing something? Or do you mean the plastic itself?
Thanks, btw :) I know I'm not saying it enough...
There are two problems with the buttons. One, the original button doesn't get properly guided by the faceplate. All of it's support/guiding came from the metal of the floppy drive (which is obviously no longer present). This means that the buttons could turn and generally "float" at the moment which would look shit. I want them to still be neatly lined up even if it is split into three. The second problem is getting them to stay connected to the button inside. The type of button I wanted to use has a small plastic (looks like ABS) shaft - the same type as those mounted on the MiST, just longer, which isn't very good for glueing to and can turn as it wishes. It's no good having a fancy three way button is it's going to look crap.
Bryce.
Ah, so it is the plastics; my first thought was you were talking about the linking of the buttons.
Funny thing is, when you first said you were going to use the button I thought "wow, that sounds hard, but if he says so..." :D
Small update. Found better buttons and did some trials today. These buttons can't spin and have a better shaft for mounting to. Here's the first "position trial". I'll make this permanent later and then I can finally cut the original button :)
[attach=2]
[attach=3]
Stay tuned...
Bryce.
Ohh AND they have colors, too!
You won't see the colours when the original button is glued on top :)
Bryce.
But.. I like colours :(
Good, grey is a colour. :)
Bryce.
Ahhh yeah, though technically it's a mix of black and white, can you add two non-colours to get a colour? :D
I'm sure MacDeath can create an overly complicated pallette to explain just how many greys you can get from two "non-colours" :D
Bryce.
Mmm looking forward to multiple system palettes!
So after much planning, I finally bit the bullet and cut the button in three:
[attach=2]
Next I had to file down the buttons to get the caps to fit:
[attach=3]
Without the outer housing they flap about all over the place.
[attach=4]
With the outer housing they still don't look great. I'll need to do some fine tuning and maybe add some more guiding to get them to line up nicely, but generally I think my plan is going to work.
Bryce.
Well, it does look like an old man's teeth about to fall off, but on the flip side it does look promising and cutting went obviously well :) Maybe a bit of filing? Can't wait to see how you're going to add more guiding...
Filing won't help, I need to close the gap around the buttons where they leave the casing, that should line them up nicely. The caps are fixed securely, but the buttons have some play, so the current gap allows them to waggle a little at the moment.
Bryce.
Ah I see. I mentioned filing not to stabilise them, but for the looks of it - smooth a couple of rough edges, but yeah, if they come together nicely it may not be necessary...
Just doing the last few edits and additions to the MiST and started testing....
:( The shitty SD Card extension is causing all sorts of stability problems. Sometimes it boots, sometimes it doesn't. When it does run it suddenly decides the card was removed although it wasn't. Looks like extending the SD slot isn't an option, I think I'm going to have to remove it and put the SD card back inside :(
Bryce.
Wait-what? How? :D
I mean, of course if the extension is not an option something has to give, but the slot needs to be accessible... Am I missing something?
Quote from: Gryzor on 16:51, 25 July 15
Wait-what? How? :D
I mean, of course if the extension is not an option something has to give, but the slot needs to be accessible... Am I missing something?
Yeah, I'm not sure. I'll try screening the cable, but I'm not optomistic. I really don't want to add a slot at the side for it :(
Bryce.
Hmm, yeah, definitely a side slot won't be nearly as nice. What does screening mean? Maybe try a different extender brand?
The extenders all seem to come from the same source. They all use FPC (Flat Protruded Cable). This one was actually 3 times longer when I bought it. I didn't stand a chance of working. At 11cm it's hit and miss. I could try wrapping the FPC in metal screen, or even using twisted pairs for certain signals. The MiST board seems to be just too noisy to route this across it.
Bryce.
Ah,I see what you mean, and the source of trouble. I guess the board doesn't have FCC approval then :(
Quote from: Gryzor on 20:40, 25 July 15
I guess the board doesn't have FCC approval then :(
I'm still going to be laughing about that one on Monday! :D
Bryce.
Yeah, you're right, of course it does have approval, it's just that it's only valid for the complete, encased unit, not the monster truck you're building.
You need more than just a metal box to get FCC approval. For a start you need wads of money, which most hobbiest designs won't have a budget for.
Bryce.
I don't think that box can fit many 'wads of money' though...
Ps "most"?
Yes, most. It's rare, but there are true hobby projects that have ended up as full blown products.
Bryce.
Ah, ok, that's no hobby by then, then.
Ok. after sleeping over it, I've decided to remove the extension cable and make my own extension with twisted wires. I'll let you know if it works.
Bryce.