Exiting the Loop

It's getting late and the teenage trick-or-treaters just stole the whole bowl of candy, so RetroChallenge must be coming to a close!

Time is up, PDAs down... we all made it! I loved the smaller group this year, as I was able to keep up to date on everyone's progress and learn some new tech stuff.

Since we all did such great work, I proclaim we are all "winners"! Every participant gets a RetroChallenge keychain, pin, and a NSFW mouse pad! (Well, it's just the shirtless Commodore guy by the pool.) Urbancamo and I will start judging the entries and choose a "winner" among winners ASAP. We will post the final summaries and results in the next few weeks.

In the meantime, check out our gopher site that is now completely up to date (or web proxy).

Thank you to everyone who participated!

RC2024/10 Results...Less than a Year Late!

With so many entries for RC2024/10 (a record, i'm sure!), and having already put in so much work during the month, I really let things slide on the RetroChallenge judging front. But at last, we have results for more than just the RC2014 category. And the "Winner" is....
"Who on earth would want to emulate an MZ-80K?" Tim Holyoake, that's who!

Voters and judges loved his efforts and his blog updates. He will soon receive his 6802 Nano SBC, MC14500B ICU chipset, pin, keychain, and round of applause. He joins Robert Price who already won the Grand Prize for the RC2014 category.

Aside from Tim and Robert are more prize winners based on the voting, but in no particular order:

• stepleton
• trcwm
• Digicool Things
• Paolo Amoroso
• Olav
• shieladixon

and I will be reaching out to you all soon to get your mailing addresses.

But, as we all know, RetroChallenge isn't about the prizes... it's about the nostalgia and pride in a job well done. Even if you made just a little progress on your project, it was all worth it. And so, I will take a moment to call out some Honorable Mentions for their dedicated service to retrocomputing: xiled, Digitalrampage, epooch, semach.the.monkey, morecat_lab, and ecliptik who each had awesome stand-out projects.

Click below to see the full results and summaries in no important order ...

On the Final Stretch!

We are on the final stretch of RC2025/10, with awesome progress and great writeups, videos, and photos. Here are highlights of recent updates:

decle's Drof Computox Reverse Engineering and Documentation

LambdaMikel's MPF-1B 3-D Graphics

Louis Paul's 2048 game on the Midway 8080

urbancamo's Coding by AI for VAX/VMS

MSW@ORAC$ basic nqueens
MSW@ORAC$ link nqueens
MSW@ORAC$ run nqueens
N-Queens Problem Solver
========================

Enter board size (N): ? 8

Solution  1 :
. . . . . . . . 
. . . . . . . . 
. . . . . . . . 
. . . . . . . . 
. . . . . . . . 
. . . . . . . . 
. . . . . . . . 
. . . . . . . Q 


Total solutions found:  1

purist's Radeon R500 by Hardware Registers

Robert Price's NES / Famicom joypad on the RC2014

ep00ch's RC2024/10 updates and gopher site

RC2024/10 Entrants List

RC2025/10 HalfTime Update!

Here is your RC2025/10 HalfTime Update! Everyone, except me, has made awesome progress already. This is a seriously impressive group of contenders: pages of code, stunning photos and videos, and some truly remarkable results. I am feeling incredibly inspired... now, it's my turn to get moving!

Status: Making Progress...

---

decle

Platform: 48-volts (probably)
Project :

I'll attempt to reverse engineer and document The Drof Computox, an electro-mechanical noughts and crosses machine. It seems to have been built by a hobbyist from telephone exchange parts perhaps at some point in the 1960s.

---

Initial Comments: I am personally pumped to see the 48V guts of this thing!

Halftime Update: Wow, decle’s series of posts is a beautiful and fascinating look into the one-of-a-kind Drof Computox. More telephone switch than digital computer, we get to see what really makes this machine 'click'. The X and O light guides are so simple, effective, and unexpected. Decle even begins tracing the history of similar machines and patents to uncover its mysterious origins. This meticulous documentation of hardware, electrical and control-logic details, and mechanical computing history makes for an awesome project.

---

LambdaMikel

Platform: Microprofessor MPF-1
Project :

Previously, I built a graphics card for the MPF-1B. So far it has done text output and Mandelbrot fractals. For RC2025/10, I want to see a rotating 3D cube on it! The code already exists, but needs to be ported to the MPF-1B and use the GRAF-X "VDP" instructions instead of driving a graphics LCD display. Also, the GRAF-X hardware will need double buffering, requiring a larger MCU - the plan is to switch the ATmega 644 that's currently used to an ATmega 128 which should have enough RAM for that.

---

Initial Comments: Not content to simply learn Z80 assembly code on the Microprofessor MPF-1, LambdaMikel has returned to add 3-D graphics to its repertoire.

Halftime Update: After resolving a clock incompatibility, LambdaMikel got off to a strong start with his 3-D graphics processing hardware and library port for the Z80. His well-produced vlog updates are a great demo of how to make retro silicon and modern microcontrollers play nice together. He’s already manually spinning a 3-D cube on the color display... talk about giving the old Z80 a new dimension!

---

Louis Paul

Platform: Midway 8080 hardware
Project :

I'm still a software guy, so the challenge for this year is to make a 2048 game which will run on the Midway 8080 hardware, a black & white arcade system. My plan is to read the documentation, write the 8080 assembly code, assemble it and run the binary on MAME.

---

Initial Comments: Reminding us of the first arcade game to use a microprocessor, Louis plans to add a modern classic game to the Intel 8080 based Midway 8080 platform! I can't wait to see the results.

Halftime Update: Louis Paul is porting the popular sliding-tile game 2048 to the vintage arcade hardware of the Midway 8080. Using MAME, he mapped out the hardware, implemented an 8×8 font and text-mode video system, handled input from arrow keys and coin inserts, and is building the game state machine to manage “insert coin, play, game over” sequences. What a great choice for a re-imagined vintage arcade game!

---

urbancamo

twitter : @urbancamo
Platform: DEC VAX
Project :

Determine how good AI is at writing code for languages supported by the VAX/VMS operating system.

---

Initial Comments: Ooooh, maybe UrbanCamo can use AI to create a VAX AI program? ... that can create other, more intelligent, VAX programs ... that can become self-aware... On second thought, maybe just a game or something.

Halftime Update: UrbanCamo is off to a fast start experimenting with the Claude Code terminal interface (I need to try that!). After testing it out with a few VAX supported languages, he settled in on working through the an AX BASIC implementation of the N-Queens problem.

---

purist

Platform: Radeon R500 ("X1000 Series")
Project :

Radeon R500 will be 20 years old as of 05 October 2025, so it now qualifies for Retro Challenge. The primary/minimal project goal is "draw a triangle on a Radeon R500 via direct memory-mapped hardware register and texture memory accesses". This means no Mesa, no `radeon` kernel module, and certainly no OpenGL or Direct3D. Compared to other graphics units I've worked with in the past (Saturn VDP1, Dreamcast Holly, Voodoo 2), the rabbit hole for R500 seems significantly deeper, considering this is the first graphics unit I've worked with that has programmable vertex and pixel shader engines.

---

Initial Comments: Pentium, Radeon, SSD, 1 GB RAM... what is this the FuturoChallenge?!

Halftime Update: There was a day when an Intel Pentium with a graphics card would’ve been laughed out of the RetroChallenge...but here’s purist, making a strong case with this newly-retro project. He’s tackling some serious obstacles, including incomplete and inconsistent documentation of the R500 hardware, plus reverse-engineering BIOS drivers and the card’s command processors. After a few test programs and demos, he scores an early win: a crisp yellow-on-black triangle!

---

Robert Price

Affiliation: RC2014-Z80
mastadon: @robertprice@mastodonapp.uk
Platform: RC2014
Project :

This year, I want to interface a classic Nintendo NES / Famicom joypad from 1983 to my RC2014 computer. There are 8 buttons on the joypad, but only 7 pins on the connector to the console. This means something interesting is happening to send data to the console from the joypad. This project will involve designing and building both hardware and software.

---

Initial Comments: Robert Price is back after his awesome prize-winning RC2014 entry last year.

Halftime Update: Robert is at it again with his methodical and clear posts. He explains how the NES controller sends data, designs a PCB to interface it, writes a BASIC program to bit-bang the controller input, then moves to Z80 assembly and finally writes a reusable subroutine. His quick video shows the working controller in action, updating LEDs on the controller board corresponding to button presses. Nice work!

---

Status: Stalled

---

ep00ch

twitter : @ep00ch
Platform: gopher
Project :

I need to finish updating results for RC2024/10, send out prizes, and post everything on the web and gopher sites. Shameful penance for putting it off so long.

---

Initial Comments: What a dope. Get this done, man!

---

RC2025/10 is underway!

On your Harvard Mark(s) 1, get SET-1530, GoTek!

Despite the late announcement, we are back on track with five competitors, another pending, and expect many more to sign up in the next week. It's not to late to sign up!

The Australian Computer Museum Society has posted more details and a summary of the prizes they are offering if you host your project on their public forum. If you already signed up and want to switch to their forum, just update your entry or let me know in the comments. Checkout the ACMS feed on the sidebar to keep updated!

READY.
RUN

Announcing RC2025/10

Don't fret, RC2025/10 is set! Next month's activities will be organized and hosted by the Australian Computer Museum Society. They will post more details here soon. In the meantime, sign up now!

As they prepare to host RC2025/10, I will post the too-long awaited results of RC2024/10. Thank you all for your patience and support!

Judging Updates and VCF SoCal

A few updates:

urbancamo and I got our act together and judged the RC2014 category pretty quickly after the event to meet semach.the.monkey's publishing deadline for the November RC2014 newsletter. So to make it officially official:

Congratulations to Robert Price for his RC2014 rotary encoder entry! His blog is a great resource for anyone looking to integrate a rotary encoder in an electronics project. Robert has won a Classic II and a set of PCBs that started off semach.the.monkey's journey into homebuilt Z80 madness!

shieladixon and Olav are also RC2024 prize winners for their entries! We will get the retrochallenge prizes to them shortly.

Unfortunately, our work and play schedules haven't allowed us to sync up and finish the rest of the judging, but I promise, it will be before 2025 starts... oh, wait... well, real soon then.

In the meantime, I will be at VCF SoCal with some giveaways for retrochallengers. If you are going, let us know in the comments! I will make sure to find you. I will also have a bunch of 5.25" floppy disks for sale in the consignment area. Proceeds go to RC2015 prizes!

The Vote is Open

As promised, if you participated in the Challenge, you can vote for the winners (other than RC2014 category). Take a look at the project links in the Entrants List and then cast your vote on the RC2024/10 ballot. Vote once, but select as many projects as you like. Make sure to get your vote in on or before Sunday, November 10, and we will award prizes based on the vote and the organizer's favorites. urbancamo and ep00ch will be spending next couple of weeks reviewing and writing up all of the projects. Stay tuned for results!

The Finish Line!

Time is up, oscilloscope probes down... we did it! Even if you did not finish your project, most of of you made great progress and hopefully learned something new. There were so many entries and some great blogging. So, what's next?

1. Take today (1-NOV-2024) to make your final post and reflect on your accomplishments.
2. I will open up voting this weekend and post an announcement. Voting will be for the categories other than RC2014 and will be open for about a week.
3. urbancamo and I will start judging the RC2014 entires when the vote opens.
4. We will post the final summaries and results in the next few weeks.

Thank you to everyone who participated!

RC2024/10 Halftime Update!

Your Halftime update is up-to-date... whew! This is usually the point where we shame you all for a total lack of progress, but nearly everyone has already done very impressive work. We definitely appreciate the participation and social media updates. In addition to my project, I have been writing up a historical timeline of the RetroChallenge to celebrate the 20th anniversary. It was a good excuse to exchange emails with some of the past hosts, catch up, and send out some RetroChallenge merch.

Quote of the week:

gaming on Windows 7 on this computer feels like owning a motorcycle, where you keep it 11 months in the garage fiddling with various tubes and screws and spark plugs and innards to be able to enjoy it for 2 hours on a Saturday afternoon when it’s not raining.
--andreixyz

If you have made progress and we missed it, leave a comment!

Halftime updates after the break...

First Week in the Books

Update: Well, now I have to say something... In a bizarre case of technological convergent de-evolution, we have 3 challengers using a Z80 with the seminal MC6850 ACIA. Poor Zilog: "But we make excellent serial interfaces like the SCC and SIO!" shieladixon designing her ready-to-use MIDI interface, morecat_lab converting a general purpose serial board for MIDI, and CDP1802 trying to use his Sharp MZ-80K2 to make some hot butter-popcorn. Oh, I guess they are related after all!

We are one week in! I have been having fun keeping updated on everybody's projects. We have so many participants this year! Nearly all of you have your first post and at least a plan, while most of the you have some progress recorded. I really appreciate that some unusual platforms are getting some love here. There are some very technical projects and some simple ones focused on documenting things for those who come next. Great variety. Those of you doing endurance challenges, using your retro computers daily, I see and appreciate you! A few of the competitors are posting on gopher blogs (phlogs). Make sure to check them out using a native browser like Lagrange.

Quote of the week:

It has been a while since I entered Retro Challenge, but I think I remember what to do. It goes something along the lines of stating at the start of the month that you are going to design [something], and then at the end of the month report back in with minimal progress.
--semach.the.monkey

I know that feeling all too well! If you are feeling overwhelmed with your current project, just spend some time using an old computer and blog about it. Those are often some of the most entertaining, insightful, and rewarding projects. Or, check out the other participants and use the inpiration to do something related.

With all the competitors, I will be closing the entry form in a few days. If you don't have your entry in, do it now!

Day 1... for the Rest of the World

While half the world had an early jump on things, the rest of us are just dusting off our projects. Perfect time to give an update on the prizes:

The keychains and pins are looking great and are on their way to me! Every entry selected by the judges will receive one of each of these beauties.

RetroCheng kindly dontated two 6802 Nano SBC computers and some components. I am still gathering up the rest of the components to make complete kits. He also provided an RCA CDP1802D chip, a Nook e-Reader, just waiting to be hacked, and a TI LaunchPad dev board with his product the assembled protoboard. Lots of goodies to give away!

Oops, I almost forgot about one of the prizes. I bought a bunch of extra Motorola ICs for my 1-bit robot project. So, I will be putting the extras together into some MC14500B chip-set kits. I am not totally sure what exact components will be in there (I have to see what works well), but at the very least, there will be enough to make the Minimal lCU System:

• MC14500B Industrial Control Unit (ICU)
• MC14512B 8-Channel Data Selector
• MC14599B 8-Bit Addressable Latch
• Binary Counter, either MC14516B, or MC14040B
• Read Only Memory, either DM72LS471 PROM, or TMS2516 EPROM

And finally, the pièce de résistance, semach.the.monkey will be giving away a RC2014 Classic II kit with the final set of the original RC2014 PCBs to the lucky "winner" of the RC2014 category!

But, of course, the RetroChallenge is not about winning prizes... just ask semach "I completed RC2014 and all I got was a new career" themonkey. It is the journey that is important. The nostalgia and pride of getting something done on a computer that has been sitting on your shelf is its own reward.

Now get to that nostalgizing!

It's Time to Retro!

Tin your soldering pens, clean your cassette player heads, reform your power supply capacitors, and flex your typing fingers... It's October 1st somewhere... RetroChallenge 2024/10 is Goooooo!

We have a lot of great entries, including a very strong contingent of Z80 projects by way of the RC2014s, the Sharp MZ-80Ks, and even the PERQ 2T2's I/O subprocessor.

I also like the focus on Web 1.1 and pre-Web technologies. I did some work trimming the fat on this website and supporting non-Web project URLs (more updates to come), and I have even started a new gopher site for the RetroChallenge (Web-proxy link) to join this effort!

A few entrants started early, posting about their too-large-for-a-month projects. No problem! But, rest assured they will be only judged on their progress during October.

If you are still thinking about joining but you are not exactly sure what to do, join now and see where your retrocomputing leads you during the month. Just spend some quality time with your vintage computer!

Here is some emulated Tandy TRS-80 Model 200 BASIC fun to get you inspired:

It's on like Tele-Pong!

Two weeks 'till RetroChallenge!

We have 9 great entries so far and we are still hoping to hit 20 entries before the start. I know that a few of you have been talking about it... come get your entry in now!

20th Anniversary

I recently realized that not only is it the RC2014 kit computer's 10th anniversary, but according to legend, it is also the RetroChallenge's 20th anniversary! We are vintage! The RetroChallenge is retro! I am putting together a little history of the RetroChallenge that I hope to have finished by the end of the event, along with some recognition for the people who have kept this fun event running over the years.

Prizes

As much as I love our traditional mousepads, I am really excited about the custom RetroChallenge enamel pins and keychains that I just ordered:

The pins are perfect for your vintage computer festival lanyards and the keychain will keep your Macintosh Quadra 950, Centurion minicomputer, and IBM 5170 keys nicely organized. Maybe even your house and car keys too. Every entry selected by the judges will receive one of each of these beauties.

semachthemonkey is providing a "pretty special" RC2014 related prize for a winner of the RC2014 category. I can't wait to hear some more details from him.

I have some MC14500b 1-bit computer chipset kits that I put together from extras purchased for my RC2024 project.

Granz has kindly offered up some 6802 Nano computer PCBs for prize winners. We will gather up the components to make full kits out of them.

Finally, ACMS will be providing prizes to its members as one of its official activities.

But remember, the RetroChallenge is not about the winning! Anyone who completes the month will receive the judge's applause and the internet's respect, forever!

Projects

As the years have progressed the RetroChallenge projects have trended more and more technical, but I want to assure you all that you don't need to be an engineer to participate. Just use your retrocomputer for a month, whether it is for journaling, composing chiptunes, playing games, or using MacPaint to make some funny drawings. We are here for all of it!

RC2024/10 Registration is Open

We are happy to announce RetroChallenge for the month of October 2024! Brought to you once again by hosts urbancamo and ep00ch with support from semachthemonkey.

About RetroChallenge

In a nutshell, the RetroChallenge is a loosely disorganised gathering of RetroComputing enthusiasts who collectively do stuff with old computers for a month.

The point of this, if indeed there is one, is to challenge you to do something new with your retro-computer, to learn something new or just play for a month. It is sort of like a show-and-tell. Do something fun or interesting and let the world know. The event is very much open to interpretation… individuals set their own challenges, which can range from programming to multimedia work, hardware restoration to exploring legacy networking, or just plain fooling around. It really doesn’t matter what you do, just so long as you do it.

Take a look at the "rules" for the RetroChallenge for basic guidelines.

RetroChallenge 2024/10 Theme Categories

We have two theme categories for this event: RC2014 and Halloween Hacks. These categories will be judged and awarded separately from the standard entries. If your project qualifies, enter it into one of the theme categories! Otherwise, enter in the General category and just do your own retro thing. Check out last year's List of Entries for some examples.

RC2014

Spend some quality time with your RC2014 kit computer.

In collaboration with semachthemonkey, we are celebrating the 10th anniversary of the RC2014 kit computer (invented during RetroChallenge 2014) with a category just for RC2014 owners! Solder up the unassembled kit sitting on your shelf, write a fun Z80 program, or prototype some new hardware for it. If you don't have a kit yet, check out the selection on Tindie or Z80KITS and join the most active homebuilt 8-bit computer community!

Halloween Hacks

Get ready for Halloween with the help of your retro-computer!

With the RetroChallenge ending on Halloween most years, this is an obvious match. Write or port a horror-themed text adventure, modify some vintage e-waste with a halloween theme, or synchronize your haunted house animatronics with programmable logic controller from the 80's. If you don't mind your house getting egged, you could even write your own BASIC game and hand out printed copies of the type-in program to those rascally trick-or-treaters. Anything you want… with touch of the macabre.

Prizes

We will have some RC 2024/10 themed gear for the "winners" and we are working out details for some awesome RC2014 goodies too!

Hosting Options

Feel free to host your project anywhere that everyone can follow along. We are trying out a new reddit community where you can host your project updates. Blogger, your github project wiki, Hackaday.io, or the 68kMLA RetroChallenge forum (for Macs) are all great choices too. The Captain's Quarters II BBS is a perfect option for you low-bandwith luddites.

How to Enter

Fill out the Entry Form for Contestants and save the link at the end in case you want to update or change your information. Let us know in the comments if you have any issues signing up.

Sign Up Now!

RC 2023/10 Results!

The results are in and it's a tie! The three Grand Prize "winners" this year (one for each category) tied for first by popular vote! The other prize winners also received votes and were highly regarded by the judges. But as we all know, even finsihing the RetroChallenge is an impressive task (one that I have been unable to complete for years). Everyone who finished has earned the judge's respect and appreciation!

Stay tuned for details on RetroChallenge 2024/10!

Click below to see the results...

This Is the End!

Time's up, light pens down!

You did it... we are at the end of another great month of the RetroChallenge! Despite the limited number of entries, we had great participation this year, which is the way we really like it.

I will always remember this RetroChallenge as the one where I completely ignored my project and instead met up with urbancamo on his visit to Southern California. We did a version of "October Offline" as we checked out the USS Midway Museum, ate a bunch of Mexican food, and went to an (American) football game to see the Los Angeles Rams and Ice Cube. What a great time, and a great guy to co-host this event with!

As promised, if you participated in the challenge, you can vote for the winners. Take a look at the project links in the Entrants List and then cast your vote on the RC2023/10 ballot. Make sure to get your vote in on or before Tuesday, November 7 (conveniently Election Day here in the USA), and we will award prizes based on the vote and the organizer's favorites. urbancamo, ep00ch, and an ACMS board member will be spending next couple of weeks reviewing and writing up all of the projects. Stay tuned for results!

Radio Repair room on the USS Midway... at least somebody is getting their project done!

RC2023/10 Halftime Update!

We have a small group of contenders this year and it is nice to see that they are nearly all making great progress. I also really appreciate the variety of projects this year. If you are making progress and have some blog posts we missed, let us know in the comments.

Mousepad prizes have been ordered, and we can expect to have a few prizes from the Australian Computer Museum Society as well!

Here is the halftime update (after the break), or just keep an eye on the RC2023/10 Entrants List!

RC2023/10 IS ON!

RetroChallenge 2023/10 has begun!

It's the 1st of October somewhere, we have a few solid RetroChallengers, and I expect we will have many more joining us this week. It's not too late to enter! NOW, GET STARTED!

urbancamo, ep00ch and Adrian from ACMS will be working hard to keep everyone updated and get you timely halftime and final summaries and results.

Shout-out to the Australian Computer Museum Society for incorporating the RetroChallenge into their membership activities.

Announcing RetroChallenge 2023/10!

We are happy to announce RetroChallenge for the month of October 2023! Brought to you again by hosts urbancamo, ep00ch, and now members of the Australian Computer Museum Society board! Thanks to Adrian Franulovich from ACMS for offering to assist with keeping things rolling along smoothly.

About RetroChallenge

In a nutshell, the RetroChallenge is a loosely disorganised gathering of RetroComputing enthusiasts who collectively do stuff with old computers for a month.

The event is very much open to interpretation… individuals set their own challenges, which can range from programming to multimedia work, hardware restoration to exploring legacy networking, or just plain fooling around. It really doesn’t matter what you do, just so long as you do it.

Take a look at the "rules" for the RetroChallenge for basic guidelines.

RetroChallenge 2023/10 Theme Categories

We have two theme categories for this event: Endurance Challenge and October Offline. These category will be judged and awarded separately from the standard entries. If your project qualifies, enter it into one of the theme categories! Otherwise, enter in the General category and just do your own retro thing. Check out last year's List of Entries for some examples.

October Offline

Take a break from online social media!

Enhance your mental health by taking a break from online social media. Use the opportunity to check out a local makerspace, computer museum, or computer user-group meeting and share your project with real people. Maybe get your old computers fixed up and lead a scout meeting about vintage computers, or, you could base your project around some need of your local computer museum. Whatever it is, give up social media and be truly social!

Endurance Challenge

Really use your retro-computer for a month!

Getting back to the ideals of the orginal RetroChallenge, we are challenging you to use your vintage computer for a month doing normal stuff like word processing, budgeting, sending emails, surfing the web, gaming, dot matrix printing, etc. Document what you did, what works, what doesn't, and what solutions you found. We will want to see lots of update posts, but we don't expect much engineering. The Captain's Quarters II BBS has kindly provided a forum as an option for your low-bandwith progress logs. As a final nod to the original RetroChallenge, the best blogger for this category will be based on popular vote!

Prizes

ACMS will be digging up some prizes and we may have some RC 2023/10 mousepads for the "winners".

How to Enter

Fill out the Entry Form for Contestants and save the link at the end in case you want to update or change your information. Let us know in the comments if you have any issues signing up.

Sign Up Now!