Bacteria's project: "Project Unity"

[bacteria]

Progress - the extended CD blue cable and the extended drive board wiring works:



Jobs remaining (in rough order):

* secure the drive board to its new location on the motherboard
* remove the RF enclosure
* wire the 5v and 12v lines to my power block rather than the massive Amiga power supply
* remove the A/V ports, these will come in useful in the main casing
* dump composite and go for RGB wiring
* wire to the controller port directly
* secure the motherboard in place above the GameCube and player boards
* make another video clip
* make a slightly larger enclosure for the assembly and make raised area so to stop the innards being seen from outside system
* finish off the surrounds and paint the tops of the CD enclosures (not front yet)
* make last Amiga CD32 clip and edit video for upload

No benefit in relocating the capacitors on the drive board and probably won't relocate the capacitors on the motherboard either, no point if don't need to.

One aspect of note, you might have noticed that the CD is a burnt disk, and you may ask why given that I don't endorse using burnt games normally; well, the reason is that the Amiga CD32 console I won on ebay "happened" to come supplied with a set of CD's with every compatible game there is; buying original Amiga CD32 games are expensive and in very limited titles if you do get any in the first place; and Commodore went out of business about 16 years ago so there is no interested loss from their ported DOS games anyway! I'm going to work through the disks in due course as there'll probably only be a few of the titles i'm interested in anyway. When i've found the titles I want, i'll probably keep my eyes peeled for those specific titles on ebay if I can get them cheaply sometime; I do prefer original titles wherever possible.


Going to have to replace the controller wire on the master controller as i've got a 9 wire shielded cable, 4 metres, to replace the 2 metre one.

[bacteria]

Ok, so wired up the 5v and 12v lines to my power lines; the system booted if "no CD present" (ie the gap between the two infer-red LED's open) with the right voltages, however, if CD present, (ie gap closed), I was only getting about 8v instead of 12v and about 3.5v on the 5v line. The three 7805's on a fairly small heatsink block were overheating, the heatsink was very hot to touch; so put a fan on top, kept the heatsink quite cool, but no difference to the Amiga running.

I knew it would be a close run thing, the Amiga is rated as needing 0.5 amps on the 12v line and a whopping 2.2 amps on the 5v line. This is why I put in three 7805's to provide the amperage needed; however didn't work.

I had three choices:

1) Use a computer PSU - I had a couple of old ones; one of which didn't seem to want to work, and an ATX one; so anyway, shorted the green wire to ground to run the PSU without a computer board present, sure enough, fan was working, but after a second, got a BANG from the PSU, so whilst it was still seemingly working ok, I disconnected the PSU from mains and threw the PSU away; clearly something blew in the unit, probably a capacitor I guess - no smoke, but a bang isn't good news; probably the PSU just died.

2) Looked for a regulator that could do decent amperage, ie initially enough for the Amiga; the TI chip I have and not used, rated 6 amps at 5v would be fine but it needs as one of its components a 200uf ceramic capacitor, they are expensive - would cost about £24 for two 100uf ceramic caps; that is crazy; a pre-built (assuming it is) is closer to about £84, which is nuts; so that option was out.

3) Just took my usual cavalier attitude of "try and see", so attached two 7805's to a spare GameCube heatsink (which are large), wired with 6 amp cable, and rather than using a 12v GameCube power supply (3.25 amps), used a 12v power supply from an old computer monitor, rated at 4.16 amps. This was my preferred route given the above issues. I can easily use this power supply to replace the GameCube one for my power lines with the various regulators after all.

Anyway, tried it, and it works; the large heatsink keeps the 7805's cool too of course. Two 7805's in parallel I thought should logically increase output from 5v at 1.5 amps max to 5v at 3 amps; seems to be the case as the Amiga runs fine with a CD game now.

So, next job will be to see if I use this power supply unit on my power line unit will still make the Amiga work fine - if it does, then it proves I needed a larger PSU in the first place; if not, i'll have two PSU's running everything, two GameCube PSU's would provide 12v at 6.5 amps after all, which should hopefully be enough to run the NeoGeo, with any luck.

That's the thing with this project, every time I make a step forward I have to consider its impact on future systems and also past ones made already; which is after all why a project like this is so hard.

[bacteria]

Think I might have found out why the old power unit I made didn't provide enough amperage, I used thick 6 amp wires apart from the ground going to the on/off switch which was about 1.4 amps rated, :facepalm:

Anyway, using the 4.16 amp 12 power supply; all works great. The GameCube heatsink gets warm with the 7805's but fine as passive cooling.

[bacteria]

Made some good progress.

Wired RGB to the CTA1145X chip, not tested it out yet though. Removed the A/V plugs, made struts to hold the Amiga board above the GameCube; there is about 3mm clearance approx at the closest parts. Need to make sure everything looks ok before turning the system on as a bad short could ruin all the work so far.

Need to take more pics, another video clip, test the RGB out then secure the whole assembly onto stronger board, build the surrounds for the CD enclosure, paint it, etc. A fair bit of work remaining before can make a last video clip for this system and compile it for upload.

At least the pics below show "the vision" so far. I need to make it into a proper enclosure yet too.

[bacteria]

So, tried RGB from the Amiga CD32, tapping off the Sony CXA1145M chip. It is designed normally to take in RGB and covert the output into S-video and also composite. This chip is a lovely chip if you have it on a board, as it means you can output RGB easily, irrespective of if the console only claims normally to do RF. It was therefore very easy to RGB on the Sega SMS, was really handy on the UK version of the TurboGrafx for the same reason (the PC-Engine needs the RGB lines amplified normally), and on the Amiga CD32 too. If you tap off the TP9 lines, as seems the usual method, then the results are supposed to be poorer as the S-video conflicts, tapping off the CXA1145M chip makes this issue redundant.

Here is the pinout for the CXA1145M chip:



...and as it looks on the board...



Here is the output on a PSone screen, RGB mode. Using one of these screens for testing purposes, so I know RGB works before later in the project I wire all video modes to a Scart socket. The pictures came out fine; the image on the screen certainly looks crisp and nice. Camera pics are slightly out of focus!





Audio can be tapped as usual from the left and right audio plug contacts on the Amiga board.

More on the project:

Here is a pic of what the board looked like when ready. The struts (white plastic tubes) are to keep the drive board in place strongly enough for the plugs from the drive unit to insert ok.



And here's the power lines on the back of the board. Didn't remove the mains plug adaptor from the board as there was no point. Blue is 5v line, red is 12v line and black is a grounding point.

[bacteria]

Ok, tested system with the GameCube on Bomberman Generation again, it's a good game to test the shoulder buttons with as well as joystick. All works perfectly, which i'm pleased about as the cable from the console to the master controller is 4 metres long (about 12 feet), which is about double the length of a normal controller cable. I figured it made sense to use a long cable so the base unit can stay where it is and the controller cable can be long enough to use comfortably while i'm on the sofa!

Had to make a revision to the master controller anyway, needed 9 wires for controllers not 8 as maximum; so the Playstation male and female controller ports are no use, the male port is 9 pin, but the female connector is only 8 pin as one pin is missing on these controllers. Instead, using an Atari style male and female port (serial port 9 pin); so did the necessary wiring, checking the work fully - as mentioned, works fine.

Here's a pic of it, connected 9 thickish wires into perspex to make it easy to join up wires to it as the project progresses, I need to find/make a housing for the external part going to the master controller to protect the wires and have something better.

[AppleQueso]

found any kind of casing yet? Any idea how big this is going to be when it's done?

[bacteria]

Casing - going to be home made, and in the shape of a cube ideally.

The board i've used to mount the system on is 33cms wide, 31cms deep (there's going to be a large 9" fan at the back of the system), by the time i've built carriers and the case surround, I estimate the final construction will be around 36cm x 36cm x around 36-40cm. Given the mass of boards, fans, drive units, wiring; this is compact. One issue though will be weight, complete guess here but it'll probably end up around 15-20kg when all done. That's a lot of electronics!

[bacteria]

Spent a few hours today on the master controller. Built up the side with thick cardboard, 21mm thick, added a few struts for support too. Put in a decent rumble motor, which needs 21mm height to work. The top perspex piece was added and screwed into place into wood.



Surplus perspex from the controller top removed, so proper access to the shoulder buttons now. Pic below of the master controller, the two holes are for joysticks as needed in games.



Placed and secured the GameCube board in place onto a new piece of perspex, a better shape.



The case and sides will of course be painted, but leaving "as is" for a while during testing phases with the consoles, as when finished, the shoulder button areas will be filled in and make smooth and seamless, which will also mean the unit will be in effect sealed - not doing that until I know everything works later in the project, just in case.

Had thought before about making a vacuum formed backing, but no real point, may as well keep it flat, and maximise the areas available.

The controller feels very nice to hold and easy access to all buttons.

Going to secure the console controller section to the master controller by magnets, more on that later.

The front of the case will be painted soon to look nice; the idea is that every game can have it's own graphics on the controller and each used button labeled to its game use, rather handy because when you come back to a game after not playing it for a while, saves the time needed to try to remember by trial and error what does what. The decals will be printed onto medium thick paper and secured in place by a top section which will be kept in place by magnets. I know you'll be impressed when you see it completed!

[bacteria]

Secured the joysticks for the GameCube onto the controller backing. The joysticks are in precisely the right position to pop into the master controller, and then move in the holes easily.

Firstly, used a bead to secure the joystick into the right place, then drilled holes through the perspex to solder to the joystick points, then applied plenty of hot glue around the area to make it look nice and also provide a lot more strength to the joint. Then, in a process I used in the old GBA addon to the Plug'N'Play Mini system a couple of years ago, used a piece of metal over the gas hobs to get it hot enough to melt and mould into the desired shape. When painted, you won't see the hot glue of course and the assembly will look more seamless



...at the moment...