MiST inside Amiga 1200 case with keyboard.

[Sorgelig]

Here i want to show my project.

I have a spare A1200 case and keyboard after replacement on my real A1200 computer by new one. So, i've decided to put my second MiST board (Thank to Till Harbaum and Lotharek for granting me another MiST board!) into Amiga case. With another important addition as Keyrah v2, i could use original A1200 keyboard as an generic (almost) USB keyboard.

here is the overview of connections:


later, i've discovered that SD card extender is too long and produces read/write errors. So, i had to re-arrange the MiST board and solder my own shorter ribbon cable. External SD slot also moved to lower part of case with more solid retention:


Back view:

Red button is reset connected to the left MiST button.

External SD slot. Eject button has 2 buttons integrated. One side press is OSD key, another side press is User button (usually reset within the core).


LED connections. Three standard A1200 LEDs are connected to respective MiST LEDs. I had to modify the LED board, Originally A1200 LEDs have "common cathode" connection, while MiST requires "common anode". So, i've desoldered LEDs (be careful - you cannot buy them from regular store!) and soldered it at 180 degree (anode-cathode swap). Then I've connected common anode to +5V (original MiST LEDs connected to +3.3V). Additionally i've added two new LEDs indicating Num lock and Scroll lock used to indicate Mouse/Joystick emulation. They've connected to Keyrah.



I've used a scaler LKV362A also shown on pictures above. It provides excellent picture with sound on HDMI and does frame conversion to either 50HZ or 60HZ by choice.

I've added modification to ARM firmware making A1200 keyboard more convenient to use.

Here is how new computer looks like:

[mahen]

Wow, you addressed all the issues I referred to in the former thread !! Very clean work, congrats !

I would definitely love a more detailed tutorial but I understand it would be quite time consuming for just a couple of persons

As I said earlier, I pre-ordered the new A1200 cases from Philippe Lang that look super sexy and have mount points for an A1200, a Raspberry, a MiST and a Keyrah. Apart from that, all the rest has to be taken care of (ports, sd card access, leds...).

Regarding LEDs, do you think this item would do the trick (as I have no out-of-order A1200 to get the pieces from) : http://amigakit.leamancomputing.com/cat ... cts_id=564 [unfortunately this item is NOT in stock but maybe it can be found somewhere else]

I guess one could find an out-of-order A1200 somewhere instead...

[Sorgelig]

Regarding LEDs, do you think this item would do the trick (as I have no out-of-order A1200 to get the pieces from) : http://amigakit.leamancomputing.com/cat ... cts_id=564 [unfortunately this item is NOT in stock but maybe it can be found somewhere else]

I guess one could find an out-of-order A1200 somewhere instead...

you can find it on eBay.

As I said earlier, I pre-ordered the new A1200 cases from Philippe Lang that look super sexy and have mount points for an A1200, a Raspberry, a MiST and a Keyrah. Apart from that, all the rest has to be taken care of (ports, sd card access, leds...).

not sure if SD slot close enough to make SD extender. Otherwise you can use trapdoor to access SD (that's how it's supposed to be b this design).

[Atmosfear]

Really nice MOD, now only the floppy Drive Sound is missing to make it feel like a real Amiga

[Sorgelig]

I'm not a big fun of floppy sound, but it can be added through audio mixing in FPGA core. So, it can be requested from Minimig core developer.

[fury23]

Great project, my congratulations!

It will bi nice to have the same Mist with another connector layout, suitable for easier mounting in custom cases.

[SuperBabyHix]

This looks fantastic, so clean looking. If I could ask a question, what is the reason for using a SCART to HDMI converter instead of a VGA to HDMI converter? I assume this is not using the MiST's built in scan doubler. Is there an advantage? Does it perhaps have less flicker in the interlaced modes?

[soviet9922]

Great job

[d0us]

Very nice!.


Gonna try this

[Sorgelig]

If I could ask a question, what is the reason for using a SCART to HDMI converter instead of a VGA to HDMI converter? I assume this is not using the MiST's built in scan doubler. Is there an advantage? Does it perhaps have less flicker in the interlaced modes?

1) Signal after scandoubler is not VGA compatible. Lowest Vfreq for VGA standard is 56Hz while most cores provide 48-50Hz. Lines per frame is also out of VGA spec. So, the only VGA compatible thing is connector
2) HDMI has near zero tolerance to video parameters for most TVs. So, you have to have scaler for resolution and frame conversion. if you plan to use TV and most monitors.

actually, before put MiST to A1200 case i hade more complicated video setup. I've used VGA video spliter, one output of which was connected to SCART input of this scaler, while another output through simple VGA-HDMI converter fed to HDMI imput of this scaler. And then i could use both 15khz and 31khz video, but i had to use button on scaler to switch the input. Since i seldom use 31khz video, i decided to omit VGA splitter and VGA-HDMI converter.

Actually, 99% of cores originally had 15KHz video, so i don't see the reason to use scandoubler. Scandoubler was made just for those very few monitors able to handle out-of-spec VGA signal.

I'm planing to make my own scaler on FPGA. So, it will be able to handle high range of video from PAL to real VGA modes and output to HDMI.

[Sorgelig]

Some user asked how i've made back panel and what materials i've used.
I've used plastic from old PC keyboard. The bottom part of that keyboard was flat and wide to become a back panel
I've used some parts of old DB9 connector as a template for hole. Used MiST case with circle holes for MIDI as a template as well. Then some careful measurements to make other holes. It took a lot of time actually. So with enough of free time it's definitely doable. DB9 connectors have screws to keep in place. USB connectors have side springs which i've bent outwards to fasten it tightly. MIDI connector board glued by super glue because i had no idea how else to fasten it. Then applied hot glue on top.
Audio connectors fastened by hot glue. HDMI extension cable i've used has ears with screws - so fastened the same as DB9.
Power connector is a standard USB Type B fastened with hot glue.
All connectors are pretty solidly fastened. Although some of them fastened by hot glue, it's not a problem if case won't be hot. Since there are no devices produces noticeable heat inside, using hot glue is ok. Just need to keep in mind, you cannot use hot glue to glue some connector's face into plate - it won't survive insertion force. You have to make tight hole first and then use hot glue to keep connector by perimeter. And of course hot glue should be a last possible option. Any screws or other retention details will be preferable.

[Sorgelig]

About how back panel is fastened itself:
Amiga case has small ribs on the bottom. So i've cut part of each rib enough to insert the panel. So each rib keeps the panel in bottom. Upper part is fastened by screws with brackets (so i had to make those holes for screws - the only holes i've made in case) - it's visible on second picture. Actually i could fasten it by hot glue (or even by super glue) but i want to have back panel as detachable in case i would like to add more connectors.

[christianlucio]

"I'm planing to make my own scaler on FPGA. So, it will be able to handle high range of video from PAL to real VGA modes and output to HDMI"

Sorgelig you are the greatest ! If this will be available I sure will buy one. Keep up the great work. I also hope to see more updates on cores from you.

[DrOG]

Congratulations, fantastic job!!!

[mahen]

Sorgelig : your work is greatly appreciated Thanks for your explanations ! Definitely looking forward to many people building their custom cases

> I'm planing to make my own scaler on FPGA. So, it will be able to handle high range of video from PAL to real VGA modes and output to HDMI.

That would be awesome. I was considering the OSSC... If you release one please consider implementing all those neat features making the picture more bearable on big screens (like scanlines, and why not xbr-like filters which look awesome in conjunction with scanlines . Also 50 Hz screens will become less & less widespread so a (bad) compromise would be to allow optional tearing or 60 Hz PAL...

Just throwing ideas. Sorry for sounding like a spoiled kid. You must be already VERY busy.

Hmm, would be awesome if your scaler could be both implemented seperately THEN integrated into the MiST 2

Offtopic : here is the kind of thing one can achieve with an XBR + scanlines filter on emulators : http://hpics.li/756dce0
http://hpics.li/b40ee3d

[mahen]

BTW... As I suggested to Rok earlier... What about a Patreon campaign to fund work from a couple of core MiST developers ?

[Sorgelig]

OSSC is almost useless. Basically it's scandoubler with HDMI output. Scandoubler is available in most MiST cores, then just buy $10 VGA-HDMI converter and you are set.
Money used for OSSC are simply wasting. OSSC has no frame buffer and thus cannot do complex convertion. It even cannot inject audio into HDMI while $10 VGA-HDMI converter can.

[vebxenon]

Wow! What resolution are you using on Amiga Core?

[Sorgelig]

Standard PAL resolution.
Non-PAL and Non-NTSC modes require special scaler.

[vebxenon]

Standard PAL resolution.
Non-PAL and Non-NTSC modes require special scaler.

Interlaced PAL AGA High-Res 640 x 512? I use 640 x 256 on my MiST Board....

[Sorgelig]

Yes.
I'm looking for a good scaler. If i will find it, then i can try higher resolutions.. Otherwise i will have to make my own scaler which will require a lot of effort..

[vebxenon]

Yes.
I'm looking for a good scaler. If i will find it, then i can try higher resolutions.. Otherwise i will have to make my own scaler which will require a lot of effort..

Great! I'll try it. On my monitor these resolutions have a lot of flickering.

PS: I've seen that you have uploaded a new version of last stable Minimig AGA core. Yesterday new beta was released, as you can read in a new thread I've opened

[Sorgelig]

You should disable scandoubler for Minimig. Actually scandoubler in Minimig does opposite to what is expected. Instead to remove flickering, it adds flicker. So, your monitor/TV should support 15KHz/50Hz mode and provide deinterlace. Or you need to use scaler which will deinterlace the video.

[Sorgelig]

For those, who are going to put MiST inside A1200 case: you HAVE TO use US layout keyboard! Those who are going to get new key caps from kickstarter campaign should be aware that FW tweaks for Keyrah will work ONLY on US layout (UK layout is ok as well, but may have confusing inputs of those 2 different keys on non-Amiga cores - which is mostly not a problem to remember).
There won't be change in FW for other layouts because those 2 empty keys have important usage in MiST as a special keys. Actually, you can still use other A1200 keyboard layout but many keys will be messed.

So, you were warned now

[kolla]

For those, who are going to put MiST inside A1200 case: you HAVE TO use US layout keyboard!

No way... not this mess again
I am already rolling my eyes over how ALT and GUI keys are 50% swapped on Minimig Core, who ever came up with resetting on CTRL-ALT-ALT in stead of CTRL-GUI-GUI?

There won't be change in FW for other layouts because those 2 empty keys have important usage in MiST as a special keys.

Are you saying that "mystical things" will happen when I by accident press those keys when typing?
Seriously, the MIST has _three_ buttons on it, there is already several to bring up the OSD - and there is the mist.ini file where one should be able to map things, and if that wasn't enough, one can use another keyboard in another USB port, or even build a "speical" USB HID device for "special keys". It _should_ be possible to have the Amiga keyboard function as just that - a regular Amiga keyboard.

Is this Keyrah2 issue, or MIST Firmware issue - because, there are certainly alternatives to the Keyrah2.

Sorry for sounding upset... but, yeah, this upsets me quite a lot.