December 31, 2016

Lost Gems: "Frantic" for Colecovision

Now that the holidays are almost over and Christmas has come and gone, I feel like I can share a project I've been keeping under wraps for a couple of months.

Several years ago, Scott Huggins and Joseph Kollar teamed up to create a game called Frantic for the Colecovision. Loosely based on the Berzerk sequel Frenzy, Scott and Joe hoped to create somewhat of a Super Frenzy for the Colecovision. Adding in things like rescuing hostages, zapping laser turrets, power-ups and a cool communicator sequence between levels. All the while maintaining the spirit of its predecessors.


5 words took 240 hours to travel across space. "Landing party captured on Mazeon" was all it said but it only took 5 hours for the mission to get started. This was the third Interstellar Organization ship to go to Mazeon to try and establish an embassy with the Automazeons but it seems to have suffered the same fate as the first two. Capture and imprisonment at the hands of the Automazeon robots called Eviscerators.

Based upon your skill and rank you've been picked to lead the rescue mission in prison complex Rallok 96. You're equipped with a hand laser and teleportation tags for the prisoners. Blast open the prisoner cells and tag the prisoners to immediately teleport them to the rescue ship in orbit around Mazeon. There are 25 rooms spread out over 5 levels in Rallok 96 and you'll need to get all 3 keys to exit a room after saving the prisoners. You can leave prisoners behind but you'll be sacrificing them to the Eviscerators. There are five generations of Eviscerators guarding Rallock 96 on the various levels. The IO recuse ship will communicate with you between levels regarding your progress."
- Scott Huggins

I really enjoy Frenzy as most of my friends know, so I was of course interested in this as soon as I had learned about it. I did all the reading I could on its development and to my dismay, eventually learning of its abandonment. I couldn't imagine living without this on cartridge after knowing about its existence. I asked around, but finally gave up hope on seeing it released.

I guess the guys just got busy with life and had to let the project slide. Time passed and a little progress would be made, but finally, development came to a halt. I'm sure lots of us have been in a similar situation at some point in our lives. I know I have. In fact, it's taken me maybe 20 years to finally have the means and know-how to begin making myself and others game cartridges.

Well, now that I'm more confident in my creations, I decided it was probably time to tackle making Frantic into a physical cartridge. I had boards fabricated by Elecrow, received the clear shells from TeamPixelboy and decided to top it all off with laser printed clear labels.

I created 4.5 of these cartridges(yes, one copy is still sitting on the bench!). I gave copies to my two friends Mike and Tom and a copy to Mr. Scott Huggins. This coincided with the holidays encroaching, so I chose to give Tom and Mike their copies for Christmas. I love giving surprise gifts out of nowhere, so it was really fun for me hearing the responses I received.

As far as the game being "unfinished", well... I have spotted a couple of small graphic glitches, but haven't gotten far enough to know if you can complete all 25 rooms in this version of the ROM. I believe you can and it also feels complete enough for me to really enjoy playing it.

The game is really fun and it's an interesting take on the Berzerk/Frenzy franchise. Frantic totally deserves to be finished and given an official commercial release.

So far, I have gotten to I believe the 7th or 8th room. I find it very challenging, but Scott assured me it's not that difficult, once you learn how to use the power-ups to their maximum potential. I'm not all that great at Berzerk and Frenzy, so it's not too surprising! I will fight on!

I think most people that tried this game out, most likely used an emulator or Atarimax Ultimate SD Cart, but that wouldn't do for me. I needed to give this game a proper place in my gaming library, thus the need for the cart.

I am very thankful to everyone above and everyone that helped me out in some way or another in this endeavor. It's great I was able to get into contact with both Joe and Scott. Being able to give Scott his own cartridge was a good feeling. I really believe it's important to show gratitude in this life and although Joe politely refused his copy, it's nice to know he is aware of my appreciation.

And not to toot my own horn, but before anyone sends me an email asking if this cart is available for purchase, sadly the answer will be no. I have no plan to sell any copies of these, unless I get an email from the Scott and Joe saying they'd like to see that happen. My suggestion, if you're interested in a copy for yourself is either making your own or figuring out some way to finally get this finished and given an official commercial release.

The original thread on AtariAge can be read here and it should have everything you need to get going.

Take some time to check it out! Happy Holidays!


Besides handling the game graphics and level designs, Joseph Kollar also designed a box cover.

December 12, 2016

Lost Gems: "Blaster" for Atari 8-Bit Home Computers

Over the past couple of months I have been studying up on the ins and outs of cartridge creation for various systems. It's been pretty crazy... In my never ending quest to learn about all things video games, here begins the first of possibly many Lost Gems posts. It's about the unreleased Atari 8-Bit game Blaster.

I'm really interested in unreleased/prototype games. I think a lot of this started when I watched the movie Cloak & Dagger for the first time and never saw the game released. It still has me searching for those lost gems years later!

I printed some A8 PCB's recently and chose a few games that I've been curious about. For this cart I ran with the gray XE case. I realized quickly I need to brush up on opening those cases. They use plastic clips instead of a screw like the early brown A8 carts and I broke off a few of the tabs. Nothing some super glue couldn't fix, right?

"Few people even remember, much less have actually seen a Blaster arcade machine.  This unique 3-D shooting game was actually the unofficial sequel to Robotron: 2084 (set in the year 2085).  Unfortunately the powerful 3-D graphics used in the game made it very expensive to produce, so only a few hundred were made (estimates say around 500).  Another problem was that while Blaster was gorgeous to look at and fun to watch, it was a very difficult game to play.  Few players were skilled enough to reach the end, and as most arcade operators know, overly difficult games don't make much money (such was Gravitars fate).  The odd 3-D style graphics also tended to confuse people and scare away potential players (this was 1983 after all).  This is a shame because games like Blaster and I, Robot were really ahead of their time." -

I highly suggest reading the article over at, as they do a better job than I can do on its history and gameplay.

Blaster for the A8 rules! It really is a shame this game wasn't released back in the day. I believe it really could have been a hit for the Atari 8-Bit line. The 3D animation is done very well and it's a lot of fun to play. Simple to learn, but continues to give my hands a workout going for bigger scores.

Here's some gameplay footage of the A8 version:

I love the crazy Deathriders in the Outer Space stage(1:45 in the video above). They really crack me up riding those rockets! And I also love the animation and sound effect when the Z-15 Fitershipz come into the playfield(1:27 above). Awesome stuff!

All of the stages really work well together and it's a blast trying to catch the floating astronauts while destroying everything in your wake. The sounds are very arcade like at times too and it feels like a polished title IMO.

If you have an interest in Atari 8-Bit games and haven't played Blaster, you really owe it to yourself to check it out. It's fun to watch the video, but even more fun to play.

My thanks to the following for their helpful information:



If you're curious what the Arcade version looks like, check out this video:

September 29, 2016

DSO138 Oscilloscope DIY Kit

Just a quick post to show a new gadget I put together. The DSO138 Digital Oscilloscope.

It comes as a do-it-yourself kit and is priced very inexpensive. I got mine on eBay for $30 shipped, including the case. Not bad!

"DSO138 was designed as a training oscilloscope kit. It contains only the basical oscilloscope functions with no fancy features. Simplicity in structure and easiness in assembly/operation are among the main targets of the design. For these purpose DSO138 uses mostly through-hole parts. The heart of DSO138 is a Cortex-M3 ARM processor (STM32F103C8) from ST. It uses 2.4-inch TFT LCD (320 X 240 dotmatrix, 262K colors) as its display element and displays nice and clear waveforms. Detailed assembly instructions are provided in combination with troubleshooting guide and schematc. Source codes are also available to allow user to add their own features." - JYE Tech

I don't know much about Oscilloscopes, so I thought this might be a way I could tinker with one easily and have a project to put together. My kit was missing 1 resistor which I didn't have available, but the eBay seller was quick to remedy that. Assembly took me about 2 hours and maybe 30min-1hr for the case. It came with a nice color assembly sheet and instruction card with photos, which made it pretty easy. The resistors weren't labeled, so I spent most of that time metering values and sorting parts.

If you have any interest in this type of thing, maybe this is the kit for you! Here are some links that might help you along the way:

August 29, 2016

ZX Spectrum Harlequin Rev. G - S-Video Mod

After using my Harlequin a bit more, I decided I really needed to improve the video quality. The Composite output I was getting was just too crazy. Luckily, PokeMon over at the Sinclair ZX World forums has come up with an S-Video solution here that helped.

It uses the Mini DIN-8 connector, so most European users probably won't want to bother with this mod, since they can probably get superior RGB output using a modified SCART cable. Being located in the USA, this was the best video solution I could find that would allow me the option of Composite & S-Video without using using any converters/adapters. Just a handmade S-Video cable.

I read over his post/schematics thoroughly and realized I could modify his design a bit to make it a bit easier for me. Instead of running wire above and below the PCB and modding the R48 hole on the PCB, I figured out that I could just use 2 wires and 2 resistors and get the same results, running everything up top.

This is how I got S-Video output on my Harlequin Rev G. for people that have an interest in this:

Remove C35
Remove R49
Remove R8
Replace D11 and R12 with 75R resistors(soldering only the top resistor pins to the holes connected directly to pin 2-3 of the Mini Din)
Solder a wire from U48 pin 11 to the bottom resistor pin on D11
Solder a wire from the right side of C35 to the bottom resistor pin on R12

It's really that simple! But, I will include some photos of my endeavor that will hopefully clear up any questions you might have about it.


First I removed the Diode(D11), Resistors (R49, R12 & R8) and Capacitor C35.
Next, I snipped off the leads on the two resistors.


I cut two wires and soldered them to the short lead of the 75R resistors.
The end result looked like this.

After preparing the wiring, I soldered one of the resistor leads to the top hole of R12 and the other end to the right side hole of C35(leaving the bottom hole of R12 open). And I also soldered the second resistor lead to the top hole of D11 and the end of that wire to Pin 11 on U48(leaving the bottom hole of D11 open as well).

This probably sounds more complex than it is, so here are some photos:

That's how easy the mod is!


I didn't document the custom S-Video to Mini DIN-8 cable I made with photos very good. I just used an S-Video cable I had laying around, a pin out diagram I found online and used a DIY Mini DIN-8 plug like this for the other end:

I paid close attention to my wiring. Using a multimeter while I worked to make sure everything was being properly wired.

Here is the S-Video pin out diagram I used:

And here is one I made of the RGB Mini DIN-8 socket on the Harlequin:


Pin 3(Luma) on the S-Video end to Pin 2 of the Mini DIN-8
Pin 4(Chroma) on the S-Video end to Pin 3 of the Mini DIN-8
Pin 1(Ground Luma) and Pin 2(Ground Chroma) on the S-Video End to Pin 1 of the Mini DIN-8

My S-Video cable also had a grounding shield wire which I soldered onto the shielding of my Mini DIN-8 plug.

As you can see from the photo above, I also had to make a case cut to expose the Mini DIN-8 socket.


To help with the case cut, I used a template shared by Ben Veersteg on his Facebook page(Thanks Ben!) and resized it to 74mm width. Printed that out and it aligns perfectly on the backside of my Spectrum case.

This is a very tricky part of the mod, since the plastic can be brittle. What I did was used a small drill hole for starting in the middle and then switched to a grinding bit on my Dremel for carving it out to size.

Just be very careful when cutting your case. Some people suggest doing more of a saw technique, but I preferred having it round and cut to fit. So that is why I chose the Dremel.

The Verdict:

After having done all of the above, I plugged my Spectrum into the S-Video slot on my TV and was greeted with a very stable image. No more wavy/rainbow/jagged lines craziness!

I am super stoked having done this! Finally, I have a solid ZX Spectrum capable of running a nice clear image in NTSC video land. And without extra converters and such!

In the videos above, you can watch as I switch between the Composite and S-Video outputs. Notice how much more clean and stable the S-Video looks on my CRT. It's great!

And here is a side-by-side comparison for your view pleasure:

In hindsight, I think it would have helped having done this mod during the whole building process instead of after. It was tricky getting some of the parts removed after it was fully assembled and I could have used a smaller gauge wire and maybe have laid them out a bit nicer. Ideally, I don't care for the way I laid the wire on top of the U48 for example. But... It works great and that's all that really matters to me.

I really hope this post helps anyone interested in modding their Harlequin's for S-Video output. I struggled finding information, so if you need any help, let me know.

I'd like to thank PokeMon on the Sinclair ZX World Forum for coming up with this design and sharing it with us all and to Ben Veersteg for his RGB cut-out template on Facebook.


July 26, 2016

Yurkie's Colecovision Composite Mod Kit

I have been playing my Colecovision more often the past couple of years and have had pretty good luck with the RF output until recently. It just started really getting crazy with a lot of interference. When I'd mess with the cable at the back of the system, it'd get even worse. I thought it might be from a broken solder connection, so I opened the case and tried a few things without any luck.

That's when I realized it was probably time I did a Composite mod... There are a bunch of ways to do this I've learned, but I had heard good things about Yurkie's mods from AtariAge, so I decided to go with his DIY kit.

As you can see, Yurkie's mod uses a nice single 3.5mm jack for all three RCA cables.
I haven't had good luck taking photos of screenshots for video output comparisons. It seems like my photos make the RF look better than it does in person and the Composite worse than it looks in person, but I did make a couple of side-by-side shots that will hopefully show a bit how much this mod kit improves the video output.

Here are a couple of photos of the RF before the mod:

This is how it looked when I was messing with the cable.
If you look close, you can see the lines, but also, in motion, this was really wavy.

As far as the kit goes, it was really easy for me to install and I swear, the hardest part is getting the case separated! I won't document that here, because honestly, I just worked with it until it came apart and it took me a good 30 minutes or so. Here is a disassembly guide that might help with that also, if anyone out there is interested.

Yurkie's PDF install guide should be enough for anyone doing this mod themselves. I didn't have any problems at all following his guide available in his AtariAge post I linked above.

This kit utilizes a sleek 3.5mm to RCA 3 cable, to avoid having to drill 3 RCA jacks, which I find really nice. This cable was included with my kit.

Here are some photos I snapped while doing this:

First I desoldered the grounding shield.
While I had the system opened, I decided to spray some CRC Contact Cleaner in the power switch.
Here are the 4 solder points needed for the mod.
After soldering the wires to the RF board and C88 cap leg, I drilled the case with a 9/32 bit and used wire cutters to cut a small notch for the wire exit when the RF lid is placed back on. Below I try to show where on the case to make the drill hole for the 3.5mm jack. I removed the motherboard completely from the case when doing this, so I wouldn't accidentally damage it. 

Here you can see the finished drill hole and notch cut in the RF box
Almost assembled!
Here's a backside view with the RF lid in place.
The RF shielding needs to be cut so that it doesn't touch the new installed board. I cut this whole rectangular chunk out before placing the shielding back on.
And that's it! I put everything back together and was almost floored when I fired the system on. The image was very stable, bright and crisp! Here are some side-by-side photos, but keep in mind, the RF looks worse in person, because it MoVeS and the Composite output looks even better than in the photos and is very colorful and stable. These were taken on a cheap little LCD, but it looks even better on a CRT.

If you look closely at the bricks, you can hopefully see the difference!
The motion blur on the enemies isn't really noticeable to the eyes, that's just the way my camera snapped the motion.

In a nutshell... If you're still using an unmodified Colecovision and aren't happy with the RF output, I'd suggest contacting Yurkie over at AtariAge to try to snag one of these DIY kits. For $30 and some time, it's totally worth it, IMO. My thanks to Yurkie! Cheers

June 24, 2016

Up from the Crypt! - Bally Professional Arcade / Astrocade


About 20 years ago, my cousin gave me a Bally Professional Arcade system (or as I usually call it an Astrocade) he had dug out of someones trash. It included about 10 cartridges and 2 controllers. My memory of it was pretty cloudy, but I seemed to remember hooking it up back then and not having any video.

Well... flash forward to present day. I was rummaging through my stuff I have stashed away at my folks house and found this old dusty beauty. It took some time trying to find the controllers. One had fallen to the floor and was buried behind some boxes and the other was on my dad's workbench(luckily my folks know how important these things are to me and didn't toss it! lol).

So, I brought it home with me and hooked it up. It just put out garbled lines/artifacts when I powered it on. My memory was that it wouldn't even power on, so I felt like there was some hope here maybe. I didn't take a photo of the screen before I started working on this, but it was similar to this photo I found online. Only on my system, the garbled madness was completely covering the screen.

My first thought was to open the system up and do a visual inspection of the components. While doing this, I noticed the C6 capacitor was leaking and totally shot.

I ended up getting a cap kit from Console5 and a few days later was back inside the Bally of the beast. I was a bit disappointed that they send Radial caps instead of Axial, but it wasn't a big deal really. For the C6, since it's so large, I had to add a wire to extend the terminal. Wasn't pretty, but it worked.

I replaced the C10 capacitor as well, but all the others looked ok, so I left them alone and fired the system up...

Ta-Da! It worked!

I couldn't believe I was able to get this thing going again. I have heard that Astrocade's are notorious for dying, so having it work for me was quite a thrill. I played some Incredible Wizard first, since Wizard of Wor is one of my favorite arcade games and was blown away by the audio! It's the closest to the arcade of any Wizard of Wor home port, sound wise. It's truly incredible!

While my system was disassembled, I removed the old white thermal paste in-between the heatsink on U18 and replaced it with a BB sized dab of Arctic Silver 5 thermal paste.

You can see that the heatsink separates when the case is open, but I did a test and found that the case presses these two sinks together when closed.

After finishing up on everything, I let the Scribble program run for about an hour using the "0" players trick and it ran without a hitch.

So there you have it! My Bally Professional Arcade is back from the grave! Muahahaha!

Getting this sucker running sparked an interest with this system and I found out there are hundreds of programs available through cassette tapes and that there has been quite a large homebrew type scene throughout the years. I think I'll save all that for a future post though.

Thanks for reading!


Some useful links:

June 7, 2016

Sinclair ZX Spectrum NTSC - Superfo Harlequin Rev. G

This was a very exciting project for me to work on. The Sinclair ZX Spectrum computer has always been really interesting to me(our first family computer was a Timex Sinclair 1000!), but being in the USA, I wasn't sure I'd ever have a chance to own one. Natively, it is a British PAL machine, so the whole PAL/NTSC issue was really discouraging. After all my research over the years, I had pretty much given up on the possibility of having my own NTSC Speccy. There is an LGR video on YouTube, where the guy sets up a ZX Spectrum in America. He had to mod the RF Modulator to output Composite video(not a big deal), used a TV with PAL compatibility, used a voltage converter, etc, etc. There's also a video here, which shows a similar set up. It's awesome these guys have Spectrum's running in NTSC land, but that is way too much for me personally.

My interest never died though and one evening I was looking for Spectrum's on eBay. Lo and Behold! The Superfo Harlequin ZX Spectrum clone PCB!

"A couple of years ago, Chris Smith reverse engineered the ZX Spectrum ULA (you can obtain the ZX Spectrum ULA Book to read about that).
Chris also developed the Harlequin: a ZX Spectrum 48K clone based on parts that replace the ULA, so no ULA is needed.
ZX Spectrum fans continued on this development which resulted in the design that is now known as the ‘Harlequin Superfo’. The current rev G is the most stable one.
You can now assemble a complete and 100% compatible ZX Spectrum 48K clone yourself!"
- ByteDelight

What really piqued my interest with this, was that it claimed to have NTSC support as an option and that it was a 100% compatible 48K ZX Spectrum clone. I read everything I could find online about the Harlequin, but it was mostly in other languages. I did manage to find a guy named Sergey living in the USA that built one and he was helpful in answering some questions for me. He posted a lot of info over on his blog here, which I highly suggest checking out. He even has a Bill of Materials on Mouser that he put together. Very cool, thank you Sergey!

Continuing... There are a few people out there selling different Rev G PCB's. Some are Red, Blue or Green, some have ENIG finish, some come as complete DIY sets with all the parts, etc. I ended up deciding to make my purchase with, because Ben Versteeg sells everything you need for a complete setup. For around $200 USD including shipping, I was able to get a Harlequin Rev G kit with all parts(includes presoldered SMD parts), an original 48K ZX Spectrum ROM and an original rubber keyed case with a new membrane.

For me, I really wanted this to feel authentic and when I added up all the parts(if I was to order from Mouser), it really wasn't going to save me all that much money ordering all the components separately. Also, Ben is a very nice guy and even tested NTSC output and added some corresponding information in the included manual before my order was placed. Oh, and he also made sure I got a 3.579MHz crystal, which is also needed for NTSC. Thanks again Ben!

I got my package from ByteDelight after about 2-3 weeks(they are located in Holland). Ben packaged every component in separate baggies and marked them, which made following his manual about as easy as a project like this can get. I was also given a tracking code, which was nice.

The amount of soldering on this project is pretty heavy and was slightly daunting at first. I did the Diodes and Resistors first and split the project into two soldering sessions. All together it took me about 5 hours total I think. I really took my time, making sure everything was done correctly. My only error during the building process was soldering on the C3 - 680μF capacitor normally, instead of turning it on its side(laying flat). If you don't do that with a cap higher than 8mm, you can't close the keyboard/case. It was easy to correct.

After soldering on all the IC Sockets, Transistors and Capacitors, it was time to install the Pin Headers(jumpers), the two crystals, the connectors for the DC Jack, keyboard, Mic/Ear, Composite Out, RGB and also all the IC's.

One of my questions was not knowing exactly what type of power supply to use for the DC jack. I was told that any AC 7V - 19V or DC 9V - 27V, 5.5mm plug with 2.1mm pin should work. An original ZX Spectrum power supply can be used (but that is made for 50Hz I think). Which also brought up the question of polarity of the plug/pin of the power supply. Most of the modern AC adapters I found had positive center pins, whereas the original ZX Spectrum power adapters had negative center pins. I asked both Ben and Sergey about this and was informed that the bridge rectifier (D12) makes it possible to use AC and DC power supplies, no matter how the positive and negative voltage is connected.

My chosen power supply:

Model: ANU-090200A
Input: 100-240VAC 0.3A, 50/60Hz
Output: 9V 2000mA
Center Pin: Positive
Sleeve: Negative
Plug: 5.5mm, 2.1mm pin

That seemed to work fine for me. After putting everything together, I plugged the power in and was greeted with the lovely Sinclair Research Ltd. screen!

Next, I tested out some software. I had already purchased a game on cassette, so I plugged in a generic cassette recorder and did the old LOAD ""... Immediately the game began loading and everything just seemed to fire right up. I was warned that there might be some video weirdness running some of the Spectrum software and I did get some kind of odd dot crawling, rainbowey effects. Pretty odd.

I had this connected to a Commodore 1702 monitor through the front Composite jack. After connecting it to a Polaroid FLM-1511 LCD tv, the video output seemed to mellow out a bit. I'm not 100% happy with the NTSC composite output I'm getting so far, but not sure exactly what I should do about it yet. There is an S-Video mod discussed here, which Sergey said he did and had good luck with.

The Harlequin has an RCA Composite output and an RGB 8 pin mini-DIN output for video. The best option would be using the RGB mini-DIN, but being located in the USA, this only seems possible by modding(like the above link) or using some sort of SCART converter box.

I tried wiring up some inexpensive SCART/S-Video SCART/Component adapters following the RGB-to-SCART diagrams, but haven't had any luck yet.

I am having enough fun with this little computer, that I'm not too concerned about the video quality, but I could see some users being put off by the Composite video output. I will be sure to post more info on this subject down the road, if I start getting better results. If any NTSC users have done the S-Video mod or have come up with something cool to improve video output, I'd love to hear from you in the comments section.

This clone seems to be directed more towards the European PAL user, so just having the option for NTSC is fantastic to me. I am very happy the designers took these things into consideration.

Finally owning a working ZX Spectrum in the USA is somewhat of a dream come true for me. I am very fascinated by the bright colors and the crazy amount of games available.

For all of you NTSC builders, this might be helpful...

Jumper Settings:

J9 - AD724JR PAL/NTSC encoder (1-2 NTSC)
J10 - Switches horizontal sync frequency (1-2 NTSC)
J11 - Switches vertical sync frequency (1-2 NTSC)
J12 - ROM configuration (2-3 for original ZX Spectrum ROM - could be different if using EPROM)
J13 - RESET (I left this open, since I don't have a reset switch installed)
J14 - Voltage Output (Not used)
J15 - Speaker (1-2 ON, 2-3 OFF)
J16 - Voltage Output (Not used)


Y2 -  3.579545 MHz for NTSC (this is important!)

To sum this post up, I would like to express my thanks to the following people:

Chris Smith -
Jose Leandro -
Miguel Angel -
Ingo Truppel -
Ben Versteeg -
Sergey Kiselev -
Don "Superfo" Dindang