Category Archives: Projects

Project Unity

PDF of the V1.0 pcb

Project Unity is basically going to be a new PCB for the Atari 2600 that will feature a video mod, audio amp, power conversion circuity, and controls. This will enable a much smaller format for portables and make it easier to make a portable for beginners in the hobby.

I hope I got the connections right. This is the first time I have designed something this large. Videos mods are easy to separate the Digital and Analog components (resistor ladder separates them well). I should have added more ground planes on this but its a prototype so its mainly for testing purposes. The only thing I am worried about is the power converter (switching regulator type Ti PTN4050) might be a bit to close to the clock signal for the Atari but its buffered by a couple 100uF caps so it should be ok.

The board measures 4.65″ x 3.45″. Has built in power converters (to up a 3.7V Lithium Cell to 5V), audio amp, video mod, and controls for the left player. Stereo jack, right and left difficulty switches, black and white switch (some games use this as a control). Only thing it misses is the Right control port as Serial ports are dam huge.

Everything soldered in place. Some stuff needs to be replaced but its working!

Ok the board is going to need some revision. The video circuity needs to be placed on the other side of the board along with a page worth of issues. Good thing the prototype at least works. All these issues are just nitpicks of mine.


After the success of my first two portables decided to start shrinking the size of my portables to something that would be easier to carry around. For V3 of the NESp I am going to base it off a NOAC (Nintendo On A Chip) board. A NOAC is basically a chip that emulates how a real NES works. The advantages are that it reduces power consumptions of the portable and it makes it smaller. However NOAC’s are not 100% compatibly with every single game (about 3-5 games don’t work).

The NOAC that will be used for V3

Design Goals
Make it as small as possible
Use a 3.5″ screen
Smaller footprint then the PSone 5″
Large enough to easily see whats going on
Pre-LED modded
Minimum of 5 hours of life
Lithium battery 1600mAh

The NOAC is comprised of 3 boards. The board on the left is the A/V plugs and DC input. The middle board is where the NOAC is located and the right board is where the controllers are plugged in. The only board necessary is the middle board.

The total size should be around 6.5″x4″x2″ which is roughly half the size my previous portable (SNES V1) is.

Finished the design today. Turned out pretty close to what I wanted it to be. 6.5″x3.5″x2″

I finished the case. Turned out pretty good I think. Looks a lot like a wooden brick. The buttons and D-pad are done but I didn’t take a picture of those.

Here you can see the two input jacks. The one of the left will be headphones and the one on the right will be the recharge jack.

Finished hacking the NOAC and LCD screen today.

The controller board has to be removed so the screen will fit in the case. The board contains the inputs and other various controls for the LCD screen. These have to be soldered directly to the driver board for the screen. The board on the left is the controller board and the board in the clamps is the driver board.

The trim pots control the brightness, color, and contrast. Removing the control board reduced the overall thickness of the LCD screen from 1″ to 1/2″. The inputs and trim ports where connected directly to the driver board with 24AWG solid strand hook up wire. The driver board has convenient soldering pads for this.

To fix the LCD screen into the case I used some hotglue. After I install the controls and buttons I will fix the trim pots to the case.

The NOAC was attached to the case with hotglue and soldered to the LCD screen. Slowly starting to get somewhere with this portable.

Back with good news. I finished the portable and I am now testing it.

Well enough with the guts.

The case turned out much better then I had expected. At first I didn’t like how I rounded the corners but the more I play the portable the more I like them.

The power button here is epoxied to the top of a large tact switch.

I received a suggestion to make the D-pad out of 1 solid piece of wood. I will look into it the next time I build a case.

Since the portable is so small the controller boards took up all the space on the front panel so the speaker had to go here.

This volume slider is probably my favorite new feature of my design. Expect to see it in upcoming portables.

The one on the left is the headphone jack. It automatically switches the sound to the built in speaker off when you plug a headset in. The jack on the right is the charger. It also disconnects the battery from the main circuity when you charge the battery. The portable is unplayable when charging but it is safer when charging lithium batteries.

I really like these hex headed screws. They look much better then the normal stainless steel machine screws that I previously used.

Being the first portable I built with an AEIComp LCD screen I was very impressed with the quality of the screens. They are bright, clear, and sharp.

I am slowly refining my portable designs. In my next portable I am going to make the guts of the portable as streamlined as possible. Even though no one sees the insides it is just nice not to have a nest of wires to deal with.

Atari Flashback P V1

Basically this portable will be a portable Flashback 2 with cart slot. Looking to have all the features of a normal Atari built in. Including all the switches and joystick port.

So far the Flashback Portable is working quite well. Cart mod, chopped down, video working, audio working, and it runs off of 4 rechargeable AA batteries (4.8V) with no voltage conversions.

The first Work In Progress video so far. This portable will be featured in a couple videos as I hope this will drum up more traffic for the site.

So I am waiting on the parts for the electronics I will work on the case a bit. The case is made out of aluminum bar that is 1/16″ thick. Bent it with a sheet metal break then epoxied the wood front on top.

Going to buy a 3.5″ screen for the portable as the 2.5″ screen is tiny.

This is a work in progress for my Flashback portable I have been working on. Part two. It is 100% working on the electrical side. Case construction will be finished when I get the new 3.5″ screen and redo the screen hole. A couple switches need to be mounted and the like but its close to being done.

Done with the electronics for the Flashback Portable. 3.5″ LCD finally came state side. Next step I have to do is to stick the guts into the case.

Finally got that blasted 3.5″ screen in. From now on I am sticking with AEIcomp. Sure its more expensive but the screen quality is better and shipping only takes a couple days. Anyways on to the case!

Man that 3.5″ screen looks TO big now haha.

The second player port. Took awhile to file that slot out but it looks nice. Needs a bit more sanding before I finish the case out.

That is the headphone jack. Right next to it will be a knob for volume and the B/W switch. I am going to try to finish up the case tomorrow. Just need to cut a couple more holes and then polish the aluminum up and lacquer the wood. There is some internal stuff to build so I will try to get that done tomorrow to.

The Flashback portable is almost done. Should be finished in about a week.

The metal tabs are going to be drilled then tapped so the back wooden panel can attach to the case.

The d-pad and buttons.

Controls installed today. The screen isn’t not turning on however. Hoping its not broken.

After some delays and broken screens it is finally done.

The final pictures.

The portable sports a 1000mAh battery for an average battery life of around 6-8 hours. Around 40 built in games and a cart slot that can play 90% of all Atari 2600 games.

Nintendo Duo V1

Nintendo Duo Portable V1 – Or Duop which is Pronounced “Doowop

This project will be an entry for the “Portable-Palooza” on the Benheck Forums. It could be the first dual NES and SNES portable every finished but I have to check on that.

This project was completely designed in 3D space unlike my other portables. Usually I will draw out the design on paper but due to time constraints I passed that option up.

To start I based the design off of the case design on the dimensions posted by “lovablechevy” on the Benheck Forums. Upon receiving the parts I double checked everything and tweaked the design a bit.

The portable will feature switches that will feel exactly like the button presses on a normal SNES pad (squishy over clicky). Also the portable will know which type of game you have inserted via two switches in the cart slots.

Runs off of 4 AA batteries. Haven’t calculated how long the batteries will last but I guess it will be for around 2 hours.

I finished the design of the portable. I rearranged the components to slim the portable down to the same thickness as my SNESp V2 so I really didn’t have to change much on the design of the case.

After opening the Retro Duo I was to see first hand how small the board really is. Pretty impressive to see how 20 years of tech can shrink down a SNES and NES.

To make the screen fit inside the 4.5″ limit the top section that is used for the back light is chopped off completely. I used a scroll saw then filed the rough edge down.

I desoldered the NES cart slot and board section to I can move it to its new location and bend the cart slot by 90 degrees.

Here is a pinout of the power switch that is on the SNES side of the portable. Pretty simple. This disables the LED lights on the board so I removed those.

I used some bare hook-up wire to wire the cart slot. Since I am not going far I decided this would be the best solution.

I did some testing and found it didn’t work. A couple hours later I isolated the problem to a little tiny cold solder joint.

The NES side of the portable draws 370mA. Taking in efficeintcy of 80% and a 4.8V power source, 4 AA NiMH 2600mAh cells, I found that the portable will last 3.6 hours on one charge.

The SNES side draws only 640mAh. Using the same criteria as the last calculation I got 2.1 hours on one charge.

Worked on the case today and got most of it built.

I used a scroll saw to cut the rough outline of the screen opening and speaker areas. I do this because it is allot easier to get a straight edge by filing down the edge to the line then it is to cut it.

After a few hours of filing and sanding I came out with the finished front panel. The mahogany strips for the speaker covers are just wood glued in.

The trick is to glue the front panel and the sides together at the same time. This insures that the case is square.

While the case was drying I cut out the buttons for the case. To cut them I use a zero taper plug bit. The D-pad is rough cut on the scroll saw and then filed down to the correct size.

This is how the PCBs will stack up inside the case. I changed the design a bit and managed to squeeze the whole thing in a case the exact size as the SNES V2 case.

I finished the case Saturday night. Sanded it down with 220 grit and then applied 3 coats of Lacquer. The mahogany turned out ten times better then cherry does.

After waiting overnight for the lacquer to dry I stuck the guts into the case. I mounted the screen first and then the SNOAC board and then the NOAC came last. Each one has a layer of electrical tape to prevent shorting between boards.

I found a better tact switch style. It has a rubber dome that feels exactly like a normal console controller would feel.

Only a couple more days left on on this portable. I have to wait till mouser sends me some more tacts tho.

Been doing allot of work on the Duop. I finished the controls and the power circuit today. Unfortunately the SNES side of the portable started acting up. It was like interference on the video line but the NES side was fine. I looked for spilled solder, tried larger wires, rerouting wires, cold joints, ect.. and no dice. I turned it on this afternoon and it refused to turn on. There is sound but no video on either the SNES and NES side.

This is a controller IC from a retro duo controller. I cut it out this the scroll saw and filed it down. Was allot easier then making one out of two 4020s and a handful of resistors.

Because I redesigned the case where both carts can be inserted at the same time a switch in both cart slots to switch which one is inserted as the Duo would get confused and freak out. So I installed a little slide switch. The switch will have a wooden top and will blend in with the rest of the case.

Good ole PTN04050. Will boost the 4.8V from the batteries to a good solid 7.4V with 90% efficiency.

Well because the Duo died I won’t be entering this into the contest. When the new one comes in this portable will be finished as I can drop the Duo in after only a little bit of hacking.

Been awhile since I have worked on this but now its done! After fiddling with the AA batteries I came to the conclusion that they can not provide the amperage needed to power the Duo beast. So I ordered a 4000mAh 7.4V Lithium battery which was the largest thing battery I could replace the 4 AA’s with.

So the battery I ordered was about the same size as all 4 AA batteries stacked up. To make it fit I had to cut it open and flatten it out.

The battery has 4 lithium cells which are paired up behind a protection PCB. I decided to cut down the middle and tack on some wires so I could separate the two “packs”.

I placed the new batteries inside the portable and removed the PTN04050 from the power circuit as I am going to run the portable straight off the 7.4V battery.

Testing done! Time for the photo shoot!

Final Specs
4.2 Hours of battery life
2 Hour charge time
Plays NES and SNES games
Rubber tacts that feel like a normal controller
Stereo Sound with Headphone jack
Dimensions 9 3/8″ x 5 1/8″ x 1 5/8″

Well that concludes the worlds first portable NES/SNES!

A little game play video of the Duop in action.

Atari 7800 P V1 – Design Phase

The Atari 7800 has a complex and large motherboard which makes it difficult to portablize. Looking at some old schematics that I found on Atari Age. Once Video modded most of the support circuitry for the RF module which cuts the board down significantly.

Finished the Layout of the case and control scheme. I will probably need to tweak it later to make it a bit more comfortable but this will do for now.

The overall case size came out to 5.75″x6.75″x2″ (LxWxH). This is the smallest portable I have designed so far (and it is starting out as the largest console!).

Just the case layout. Instead of using a traditional D-pad I decided to use a multi-directional 4-way switch which is just a fancy term for an Arcade Joystick that is really small. The one I am using for this project is 1/2″ wide and 1/4″ tall, perfect for portables.

The front panels are made out of stainless steel and the sides are acrylic with the insides painted black. Yes I know, not wood. Decided to mix it up a bit on this one.

Cutting Diagram

This is how I plan to cut the 7800 mainboard. After the video mod the entire upper left part is useless. The cart slot will be relocated and the power circuit in the upper right will have to be recreated. In the middle the board will be folded and attached with ribbon cable.

A/V Install Guides

Guides for the Atari A/V Mods

Read through the instructions carefully before attempting. Also read the disclaimer.

Atari 2600

Kit Install Guides

Assembling a 2600 Kit. V2.2E
Assembling a 2600 Kit. V2.2F – Current Version

Schematic NTSC V2.2F
Part List NTSC V2.2F
Schematic PAL V1.0
Part List PAL V1.0

Atari 7800

Kit Install Guides

Assembling a 7800 Kit. V2.1

Schematic NTSC V2.1
Part List NTSC V2.1

Printout and Drill Template


Reset Vector – The circuits have turned to glue man

This will be my first pinball machine to custom build. Everything will be custom built down to the programming. For the majority of the parts I bought a broken Pinbot pinball machine and removed the working parts. Other parts are sourced from ebay or pinball conventions.

The virgin plywood and its journey into the greatest pinball machine ever to grace mankind.

The old coin door. Its pretty beat up so I will be stripping the paint off with a brass wire brush and then repainting it.

Side rails and topper bracket is installed.

Close up of the topper bracket. I took it off the old Pinbot cabinet as it was still in decent shape. Had to sand it down and fill in some holes tho.

This is the hold down bar bracket. The hold down bar is the piece of metal that locks on the top of the front. Removing it allows you to remove the glass.

Cutting the opening for the coin door.

After painting with some hammer-on finish spray paint. I chose a silverish paint to match the stainless hardware better. The legs of the machine will be painted the same color.

Cutting the test playfield out of cheap pine plywood. Using a test playfield will enable me to test shots and move parts around without worrying about drilling and cutting the playfield. The final playfield will be made out of birch plywood.

Heres what it looks like with it installed in the new cab.

Installed the coin door.

Flipper buttons installed. They use leaf switches as these are directly in series with the flippers so the need to handle 50VDC and 3-4 amps.

Powersupplies and the flipper solenoids are installed.

The powersupply setup. The left one is a 50VDC powersupply and the one on the right is a computer powersupply that will supply the 12V, 5V, and 3.3V for logic.

Put the legs on. Won’t repaint them till its out of the shop so the paint doesn’t get chipped.

Bracket for the legs. I chose to use the heavy duty variety as a couple modes I have planned require you to tilt the machine.

How the layout of the head unit will work out. The score wheels are the “roll over digit”. Basically when you hit 9999 the machine will “lockup” in blue screen of death mode. To reboot the system you hit the CTRL-ALT-DELETE targets and the score resets to 0000 and the score wheel increments 1.

How the head unit is built. It has two doors. open the back one to move the score wheels out of the way and the other doors allows access to the LED displays.

Justa close up of the displays. That LED display is not functional.

Installing the pop bumpers.

Shooter lane. You can see the skill shot near the top.

Drop targets. One feature I really like about pinball machines are drop targets so I have lots.

This is what the pinball machine currently looks like. You can see the LED dot matrix display on the head unit. its resolution is 16×72. It will most likely be multiplexed and controlled via shift registers.

Mode Ideas

  • Kid Hacker Mode: All 12 year old kids can hack computers in an instant. When in this mode it will randomly pick a “kid hacker” from a movie.
  • Jurassic Park: In the first movie the young girl hacks a Unix graphical interface to lock down the compound.
  • HAL 2001: Knock down the drop targets to do what Dave does in the movie. As you progress in the mode HAL speaks slower.
  • USSR Mode: Upon entering this mode the machine will randomly freeze up. You fix it you have to “tilt” the table simulating smacking a computer to get it working again. This happens 9 times. If you keep your ball alive during it you get a big bonus. Keeps track with a nixie tube.
  • Hacking Mode:This is multistage and is the default mode.
  • Dial-in: First you have to establish a connection. Hit targets around the play field to connect. sounds will be like a 56K modem.
  • Connect to router: You need a password. Targets turn into password inputs. Will enter generic passwords like “PASSWORD”, “1234”, “PACKER04”.
  • Once connected it will randomly pick which mode you can do. Themes range from the WOPR terminal in Wargames to stopping Skynet.
  • Independence day: Upload a virus to the Aliens before the world is blown up.
  • Mission Impossible mode: A floppy disk acts as a barrier and only inserts into the floppy drive when in this mode. Copy all the files (hitting all targets) before the time runs out.
  • Golden Eye: I’M INVINCIBLE! is what is said when you lose all your balls.
  • Rick Roll is going to happen somewhere.
  • Hello World shall make an appearance.
  • Dot Matrix Printer parts will be used in the field.
  • Every so often you will get a “Permission Denied” on the screen. You can not score any points till the “Override” button is pressed.
  • Blue Screen of Death
  • Firewall mode: To get past the firewall you need to traverse all ramps.

This is a video dump of the pinball machine.

This is the second work log for the pinball machine. Not much has changed but there are a few ramp ideas and such.

Little demo of the flippers and various shots around the playfield. Next video should have working I/O so the slingshots will work.

Here is a little test of one of the 4-digit 7-segment LED displays. This is just a prototype and does not have the 16-segment alphanumeric units on.

The PCB for the solenoid controller is almost complete. Just need to wrap up the Watch Dog circuit. A Watch Dog just makes sure that the solenoid controller doesn’t lock up in case of a CPU lock up (i.e. crash). I am going to try a timer (kinda like a 555 timer) to the Reset Pin of the 74HC595 and the input of the timer to CLK signal. If the CLK signal doesn’t change for 1 second the 74HC595s will reset.

PCB done. I decided to use a 555 timer as the watch dog. Keeps part count low and reliability high. I will post some more technical details later.

PCB done for the input. It pulls all the inputs high and when the ball activates a switch the pin on the 74HC165 gets pulled low. The 74HC165 is a parallel in serial out which is the reverse of a 74HC595 essentially. This PCB has 32-bits worth of inputs and can be cascaded to allow more bits on the same DATA line.

Finished designing the PCB for the 4-digit displays for the Reset Vector pinball machine.

Along with the 4 7-segment LED displays it also has 2 16-segment LED displays to show which player belongs to that score.

Left to be designed PCB wise is a 16 x 72 LED matrix board, a 7-digit 16-segment display, and a RGB LED driver board.

I had some issues with my 74HC595’s. They seemed to “reset” periodically. Figured out the real problem while working on my displays. Fixed it with software.

My old routine

Latch Low
Repeat x times { Clk low , Shift bit out , Clk high }
Latch High

Seems that when that is low it can easily pick up interference from the data and clock line. To fix this I can put a pull down resistor on the Latch line but this requires me redesigning all my PCBs thus have to pay tooling costs again if I need spares or fix it in software like so.

Latch High
Repeat x times { Clk low , Shift bit out , Clk high }
Latch Low
Latch High

This way the latch hasn’t “reset” and eliminates glitches. Working fine now.

And it worked first try!

This will be a display above the row of targets in the middle of the playfield. It will display different words or numbers depending what mode the player is in.

To make sure the LED matrix setup will work I am going to get this board made. It will only cost $15 to get the test prototype PCB made compared to the $120 to get the entire matrix PCB made. With this I can test the programming and make sure the 74HC595’s and propeller are fast enough to do it all.

2 out of the 4 score displays are now working. Currently the code supports all 4 displays. Just waiting on more parts. Next video will feature the input and output boards working.

This will be a display above the row of targets in the middle of the playfield. It will display different words or numbers depending what mode the player is in.

To make sure the LED matrix setup will work I am going to get this board made. It will only cost $15 to get the test prototype PCB made compared to the $120 to get the entire matrix PCB made. With this I can test the programming and make sure the 74HC595’s and propeller are fast enough to do it all.

The 32-bit input driver and the 32-bit solenoid driver.

Finalized side art.

Some specs of the display:

  • 16×96 resolution, single color (red)
  • LEDs run at 1/8 duty cycle due to updating the display 2 lines at a time. Line[n] and line[n+8] get updated at the same time.
  • Row selectable for the fastest update speed.
  • Estimated refresh rate of 100Hz. It is written in spin so the driver is fairly slow but this is mainly limited to the speed you can clock into the 74HC595s that do the row and column addressing.
  • With all LED’s lit it will draw roughly 1.5Amps.

Received my JWS480P-48 power supply. It provides the 48V needed for the flipper coils. At 10A of continuous current it has plenty of power to cope with it. It also does 20A peak for awhile which is enough to power a couple pinball machines at once!

Got a lot of work done on Reset Vector. I/O is working along with sound. The game currently supports 4 players. Need to finish the playfield layout and get the dot matrix display running.