Designing and building the laptop case...
With the Compact Flash drive working I was ready to continue. Finally! The first order of business was finding a screen to use. The first noobish idea would be using an old laptop screen but that's quite hard, if not impossible. See, the Atari puts out composite video (like the yellow jack coming off your PS2) while a computer monitor takes RGB. On top of that most laptop displays are proprietary digital and therefore only work with the laptop they come in. Some people try hooking laptop screens up to their PC's and have a really hard time - connecting it to an Atari would be even more difficult and very expensive.
That left me with using NTSC screens, such as the displays in a car DVD player. I couldn't use the cheap and readily available PS1 screens because at 5" they're way to small. The thing to think about is the laptop case is going to be the size of the motherboard at least... so you need the biggest screen possible. Another factor is overscan. Old computers and game systems assume rounder, smaller TV's and therefore usually had a good deal of "border" on the edges since they assume this to be off the edges of the viewable screen for the most part. However modern TV's, especially LCD's, show pretty much every bit of a video frame making this "overscan border" even more obvious. Another strike against a small 5" screen.
A 10" laptop monitor would have been ideal, but again impossible. Most of the cheap car DVD player screens were 7" widescreen - also unacceptable. Finally I stumbled across this at Radio Shack:
It's an 8" TFT display with a bunch of extra crap built in (TV tuner, ironically Compact Flash picture display card) The price was right, $150 after rebate... I had 2 days to decide before the sale ended. Then a sales associate got the manual out and I discovered this thing had rechargeable batteries in the base!
$150 for a screen PLUS (9) 2100mAH Ni-MH AA's and a built-in charger - can't beat that. SOLD! (I did find a few dead pixels later on - oh well what can a man do?) I bought the thing, took it home and DIDN'T immediately hack it apart.
"What?" you say "You, Ben, hacker of all hacks, didn't immediately open it up? What's WRONG you with?"
I'll tell you what's wrong! See the Atari 800 had this thing called "color artifacting" What happened was in its high-res Graphics 8 mode (ahem, 320x240 with 1 color) if you made vertical lines with spaces between them they'd not appear white (or the one color available) but rather green or magenta depending on whether the line # was even or odd and what version Atari it was. Thus programmers used this to add color to high-res mode games (a good example of this is Choplifter)
Thing is, emulators have to actually simulate this as it's a feature of TV's. Therefore my concern was this modern TFT display might not have the artifacting characteristic. So I had to test out the screen before I opened it to make sure artifacting would work. It did, thankfully, so THEN I ripped apart the screen!
How nice of them to have all the crap inside this screen be modular! The LCD portion is on the left, circuits on right. Naturally the big PCB is the main guts, gotta have that. Below it are the TV tuner and Compact Flash reader. Those can go bye-bye! What rubbish. What I actually ended up doing was using the +5 volt power supply on the screen that was intended to power the Compact Flash adapter and use it to power the Atari instead. Why not?
Now that I had my screen I could design the case of the laptop. (As I usually say, and will say again, the screen is a huge factor in the design) My Atari 800 motherboard was currently in this condition:
The space I had cut out for the hard drive originally just happens to also fit (9) AA batteries. Obviously I subconsciously must have known that back in 2003 - clearly. At the bottom of the motherboard you can see the battery charging circuit I took from the TV, and how it goes to the power switch on the upper left. Alright, let's get down to construction!
As usual I designed everything in Adobe Illustrator and cut the parts with laser engravers and a CNC machine. I started with the keyboard, mostly because I'd never made a keyboard before and I really wanted to see it complete!
Above is the first step - tact switch placement on the keyboard grid. I used small 4.5mm switches so they could be INSIDE the keys rather than under them. This is a trick I used for all my ultra-compact projects, such as the NES Micro.
I wanted the keys to be nice so instead of making the text with decals I actually raster engraved it into the surface of the black textured plastic to create characters. This is much slower but gives them a good physically look and feel. In the upper left you can see the "key mesh". This is a grid I cut and laid packing tape on the back of. Once a key was attached to its hollow base I then placed it into the sticky grid, as shown below:
Next came the hard part, or rather the boring monotonous one. I had to wire up the tact switch grid to the keyboard controller in the same way it was in the original keyboard's circuit. See below:
Note the hole in the bottom of the keyboard - this is where I intended my "Cursor Mushroom Button Knob" to go. In the olden days we didn't have "mice" to move the cursor around the screen, no sir-ee! We had to use KEYS, and sometime we'd have to press a couple keys even! (Then walk to school barefoot uphill through the snow fighting dinosaurs) With the Atari you had to hold "Control" then press one of the direction keys (which are normally +, -, etc) This worked but was clunky.
My idea was to have a knob that you could push with your finger to "magically" make the cursor move around the screen. Since the OS was locked the only way to accomplish this was mechanically, and boy did I have a hard time getting it work!
The trick was "Control" had to be pressed and held before you could hit the other keys. My solution was to mount the knob (really just the top of a PS2 analog stick) on a spring with 2 tinfoil-covered discs below it. When you press the knob in any direction the first thing that happens is the disc connect - this is wired to the "Control" key. When you press a little harder the tact switches below click the appropriate arrow key and the cursor moves. While it's hard for me to believe I actually resorted to using tinfoil for something I can't deny that it works. Seriously, I probably spent a good 12-15 hours figuring out the best way to do this before I said "the heck with it!" and made a trip to the supermarket!