

Yes, the GBA is a small handheld device and already portable, however the screen is small. I wanted to make a GBA with a much bigger screen and bigger control buttons. The original GBA had a very dark screen, the SP is fine but is a bit fiddly to use as it is so small (and so is the screen) for adult hands. I wanted something better, and a screen big enough to get you more immersed in a game - hence this mod!
I would suggest that this mod is in keeping with the spirit of the other projects on BenHeck, the only real difference is it isn't making a non-portable console portable as this device was (more) portable to start with, however the process and demands of the mod are very similar. I also had a harder job Googling for information to compile everything I needed to research this project.
As with all game consoles, there are masses of games available, mostly tat; however there are many really good quality games available for the GBA - eg Advance Wars (1 and 2), Mario vs Donkey Kong, Super Mario 3 - Yoshi's Island, Mario Kart, Zoo, PacMan collection, etc (just to name a few). You can also buy them cheaply second hand via stores or E-bay (c. £4-£7 each typically inc P+P). That is the advantage of buying games and consoles when the console has been well established for a while - you can buy them very cheaply!
You need to use a tv-out card designed for the GBA in order to get the GBA to output to another (PSone) screen. The composite quality of the output is quite poor, bleeding on screen and the images are too red; so really you need to get RGB output to make this project worthwhile - it makes a big difference with the GBA - as per usual, RGB makes for clear images, crisp and the colours are well defined. Interestingly, I hooked up my PSone screen previously to an N64 I have, via composite, and was amazed by the picture quality on the N64 via composite.
You can get two types of tv-out adapters, one of which is the GBA Transverter, which I had, and it was rather nice to use it. I bought it when it first came out and only used it once - playing a GBA on a tv set is awkward due to the extension cabling and the image on the screen is blocky as the low resolution of the GBA games don't convert on a big-sized tv screen.
I included pinouts for both types of tv output. The GBA Transverter is the better option as it uses over 80% of the screen, all the horizontal - although you do seem to lose the leftmost edge (not a problem). The other tv out card gives a bigger border, so the final image is smaller on the PSone screen. I notice you can now buy a tv out card for the GBA SP, so there is no reason you couldn't do a mod with this configuration if you desire. You have various options.
What you need for this mod:
* GBA (original one, not SP model)
* GBA Transverter (or other tv card for GBA)
* NES controller (for the D-pad and board)
* A couple of lunchboxes (see dimensions at base of post)
* Electronics button switches for the A, B, R-shoulder, L-shoulder, start and select buttons. You also need an on/off button capable of turning 3 items on at the same time. I live in the UK, so visited Maplins for these items.
* Polyfiller, paintbrushes and mini roller, paint (satin/matt), clear varnish, sandpaper, mounting board card, hot glue, soldering iron with thin pencil tip, etc
* Dremel or similar, with diamond side cutter and grinders
* 14 high power high drain NiMH AA batteries, at least 2500NiMH (you can get away with 12 not 14 if you wish). Yes, you would get better battery life with C cells, but space is a consideration, and you really need over 5000NiMH minimum (high drain batteries) if running a Transverter and PSone screen from one set of batteries (I use 2 sets hence).
* Battery holders and wire connectors
* Larger speakers (8ohm) if you want to improve on the PSone's (optional)
* HINT - disassemble the wires from the NES cable - you get about 6 wires, very flexible and long - you have plenty of wires from this cable to do this whole mod!
Parts on E-bay are cheap if you bid sensibly and get a bit of luck! You will find it very hard to get a Transverter for the GBA anywhere on the net (I had one from about 2002) but the GBA tv-Converter type alternative is quite easy to get hold of.
You will probably spend (depending on how you bid on e-bay and luck of cheap prices) - PSone £25, GBA £12, NES controller £3, buttons/switches £17, mounting board/thick card (free?), paint, varnish and brushes (free?), Polyfiller (or substitute) and PVA glue £5, wiring (free from NES controller), battery holders and wire connectors £3, hot glue sticks £2, M3 flash card or similar (I got mine from www.divineo.com under GBA section, "Chips / development") for about £30. (NB - you don't have to use GBA roms, there are lots of excellent homebrew titles (eg Russ Prince's Bust-A-Move), etc - although if you own a commercial cartridge game I don't see why you shouldn't put its rom on the M3 unit, you have legitimately bought the original game after all, so no issue - the M3 just makes it easier to play the game you paid for in the first place - you can also use this M3 as a means to show pics, play MP3 music too). Alternatively, you could easily not use an M3 at all, and just play using your original GBA roms (although you will need to modify my case design to allow this easily). I use th M3 really for convenience (not swapping cartridges about when playing different games). You also need 14 photo grade AA rechargables, at least 2500NiMH c. £12.
Total cost, about £80/£110 from scratch.
Ok, on to the project work:
GBA Transverter (tv out card)
You need to solder onto the chip for the RGB connections:

The Sync (pin 3 on the PSone) wire is soldered to the pin on the Transverter (4th pin on the reverse of the Transverter, shown with red dot); and the Ground (pin 7 on the PSone) is soldered to the last pin on the Transverter (shown with the blue dot).

The other type of tv out uses the pinout below as alternative.

The RGB wires will need to connect to the Red In, Green In and Blue In connections on the PSone screen
PSone screen

Make sure you connect a wire from pin 12 to the chip on the reverse of the mobo (for the 5v connection)

On slot 2 (diagram), solder the wires from pins 5, 6 and 7 together, so you get sound from the speakers.
Before going much further, it is a good idea to hook everything up (using mains power at this stage) to make sure everything works (ignore the black cable, this was when I tried composite instead of RGB):

GBA wiring pinout:
Took a while to find this wiring pic on the net!

You don't need the GBA's LCD at all, it boots up without it, and conserves battery power without it.
You need to use a 30w soldering iron (or higher) in order to generate enough heat to leave a solder blob on the motherboard connections, so the solder doesn't come off. Before you solder a wire to these joints, try to remove the solder blog with your fingernail, if it stays rigid, you are ok - if it comes off it needs re-applying.
Butcher a NES controller, dremel away all of the mobo not associated with the connections to the D-pad

Case:
Vacuum forming is georgeous if you are skilled enough to make a suitable bench and prepared to spend a lot of time and money buying the plasitc sheets and experimenting until you end up with a lovely, commercial quality type case; however I don't have these resources and wanted to make a cheap and practical case myself.
I had a lunchbox lid which was the right size to accomodate the PSone board, buttons, D-pad, etc - big enough, but not too big. Started off with making a base out of mounting board card - rigid enough as a "skeleton".
1) Holes at top are for the speakers - using alternative speakers as the PSone speakers are tinny in comparison. They came from a set of portable MP3 speakers I had, which only gave good sound when sound levels were low, not much use for an MP3 device but ideal for a game system. I needed to raise the height of the speakers from the case, there was no room to simply mount them onto the front case directly, so I incorporated a tube between the front of the case to the speakers (hence the two large holes at the top of the pic). These are the largest speakers I could sensibly use in this mod.
2) Hole for the D-pad - dremeled the mounting area from a NES pad and hot glued in place.
3) Hacked up the PSone enclosure at the back to reduce the overall height of the final assembly. Hot glued the front into the mounting board.
4) Used Polyfiller onto the mounting board, to conceal the Psone front panel, D-pad, etc; making a slightly curved area to make the shape interesting. The finished product was left to dry and then was sanded to make it as smooth. I then drilled out the holes required for the buttons, mounted them, touched up areas with further Polyfiller, let it dry and further sanded. Polyfiller adds strength to make a rigid and strong case, but itself is prone to cracking if stressed and is powdery, so I painted on PVA glue to seal the polyfiller, once set it is extremely hard and solid.
5) Item painted, about 4 coats, then a clear varnish applied (2 coats).
The case looks smoother than this in real life, and this pic was taken before I did further sanding anyway. I used a yellow cream colour as I had some lying about and it is a nice colour; I had tried black but it shows lumps and bumps more - lighter colours are better - pastel shades.



(isn't hot glue great!)
Assembly:
Mounted the PSone mobo

Cut out mounting board and used self-adhesive foam pads to secure them to the outer PSone casing. The mounting board provides a flat surface to mount everything else onto. Speakers mounted. I am not sure in speakers are magnetically shielded or not, they act as magnets; but doesn't matter with an LCD screen after all. The speakers are 8ohm. I wired the sound output directly from the mobo which sent sound to the GBA speaker (removed earlier) to the PSone speaker inputs.

Space is a bit limited, but there is plenty of space for the GBA mobo and Transverter on the bottom half and the battery packs on the top.

(A) PSone mobo, (B) mounting board (base), (C) GBA Transverter mobo, (D) GBA mobo. This was the only configuration which fitted fine, and allowed the GBA cartridge to be at the top of the construction. I got rid of the paper tape, realised I needed to place the GBA boards onto struts to keep them firmer in place (dremeled a masking tape as it is the right height and makes nice struts!). I know this looks a bit of a bodge, but works great, and anyway, won't be seen when the case is painted.


Battery holder - made from mounting board, hot glue and paper tape. It needed to house a two 6 x AA battery holders and a 2 x AA battery holder. Just enough space to do it.

(A) NES D-pad board, screwed in place (original mounting) and hot glued at other end to keep it flat and in place. (B) mounting board, (C) GBA Transverter, (D) GBA mobo, (E) GBA cartridge, held in place by a spacer connected to the (F) battery holder section.
I am using a flashcard for the GBA - the "NDA/GBA Movie Player M3 adapter" which allows playing games, movies, pics, MP3 via an SD card on the side of the flashcard - so the cartridge itself can be kept in place permanently.

Make a case, mount the right and left shoulder buttons into it, attach the on/off button and cutout (dremel) holes for the battery covers (note, this was my version 1 rear case, final one looks different, but same principle).
Hole cut in case so you can access the SD card easily (I ended up making the hole longer in the end).

I changed the rear case a bit after this pic was taken, as below.
The finished height is exactly the same height as the lunchbox, which is ideal. This fact also helps to keep everything nicely in place and snug.
As I used a lunchbox, it was hard to make screw attachments to take the case apart in the future if repairs are required, so I didn't - I used some hot glue in strategic places to seal the front of the case to the rear, which can be prised apart if needed. This means I can't get a nicely finished join to make it look lovely, that is the trade-off.
As an adult, I can easily hold the lunchbox in my hands and play the GBA quite comfortably - being flat at the rear means it also plays easily when flat on a desk!

I had thoughts of making a moulded area to conceal the battery compartments, then had a brainwave of hacking apart another lunchbox bottom and making a slotting attachment to secure it to the assembly at one end, and velcro strips at the other. Foam padding used to keep the batteries secure. Quite a neat, and quick solution.

Rear view, showing the batteries in place

and with the battery rear case on (cutout is for access to the on/off switch).

NOTE - the hole for access to the SD on the flashcard is be covered by a thin piece of card, painted and varnished, secured with a little blu-tac to keep it flat. Cosmetic, after all!

Final product:

The draw on the batteries is large, hence two battery packs. One battery pack running the Transverter and PSone screen lasts about 10 mins before fading, and the batteries get very hot indeed. Using two sets (one each) keeps the batteries nice and cool (less draw) and you get playtime of about 1 hour 45 mins (once the voltage gets under 7.5v the Psone fails, and under about 7.3v the Transverter gives a very wavy picture). The AA batteries must be photo/digital quality, at least 2500NiMH and designed for hit drain devices. If you used C-cells, you would not have enough space in the case for them and hooking up to the Transverter and PSone screen (1 set of batteries) wouldn't give much better life as the combined draw seems to need over 5000NiMH. Ideally, a Li-ion pack of about 8v would be ideal, you can get them about 18000NiMH, but expensive. AA batteries are not the best, but satisfactory and more practical. They also recharge quickly and there is no issue if you have a spare couple of sets to use. Just taken delivery of 2650NiMH batteries, should hopefully get close to 2 hours with these (very acceptable - after all, you only play a console for perhaps 30-60 minutes at a sitting - at least, I do!).
You could use 12 batteries instead of 14 by connecting the cell pack from the Transverter to output 3v to power the GBA, reducing weight (less top-heavy then); however with the design I have used, if you are playing a game and the batteries from the Transverter and/or the PSone die you can replace them and get back to your game uninterupted as the GBA batteries are still powering the GBA itself - so on balance, this works well! When the batteries to the PSone get low, the sound continues but the screen goes shades of black; when the Transverter batteries get low, the image gets very wavy and fuzzy - easy to therefore know which set is on way out!
Final statistics:
size: (approx); 25cm x 16.5cm x 6.5cm.
Weight: 1.15kg, including batteries. This is a manageable weight.
Battery life: according to my testing: approx playtime of 1 hour 45 mins - time it takes for fully charged batteries (c. 8.44v) to reduce to under 7.5v and thereby not have sufficient power.
If I want to in the future, I could easily make the rear of the case prettier, smooth the edges, etc - and I may do so; but at the moment I am quite happy with this. As with many people's mods, the front of the case is pretty and nice, the rear not always so!
The GBA mobo and the Transverter are quite tolerant of being modded, didn't fry inspite of the testing I was doing to them initially. I did a lot of prodding and experimenting, the mobos stood up to this; and I had to learn how to solder to do this project! The mod is quite intensive but straightforward.
What you you guys think of it?

Any questions? I will do my best to answer them.
Thanks go to whomever produced the original pics for the illustrations used above I got from the net, they came from various sources.