Blog · corpus.blog/blogs/michaeldoornbos.com/posts
michaeldoornbos.com
michaeldoornbos.com
2021
I want to see scope pinouts of every pin on every chip on a VIC-20, C64 (long and short) and 128. If it doesn't exist, I may create this as a resource. Just power on and pin out, screenshot scope. Nothing running. #commodoreoriginal ↗
12 May 2021
I will never take list/array slicing in my day job for granted again. Doable, but so messy. #commodore #cryptooriginal ↗
11 May 2021
Another 128 today. I’m not sure I understand this yet, but a wonky 8563 (80 column chip) was causing an issue on the CIA at U1. Took a while to figure this one out for a friend. When did I become my local 128 repair shop? I barely know what I’m doing #commodoreoriginal ↗
8 May 2021
Out of all the vendors I deal with @futurewas8bit is one of the best. Consistent and great products. Penultimate+ and a 6502 this time. #commodoreoriginal ↗
7 May 2021
10 min lunchtime progress: Running all rotors with 26 possible starting positions on a 3 Rotor Enigma with 5 rotors to choose from (I want this to finish in my lifetime). So 1,054,560 combinations in 71 seconds(BASIC takes 2+ hours). Not bad. #commodore #c64 #crypto #enigmaoriginal ↗
7 May 2021
7 May 2021
On the couch so no screen capture. I’m sure there are efficiencies to do but it works. Moving to the next step: 3 rotor Enigma, 5 rotors to choose from First need all possible combinations. Tomorrow we’ll add 26 starting points to each and crunch numbers #enigma #commodore #c64original ↗
6 May 2021
Forming a new club. I'm calling it "Folks who run calculations on all combinations of a 3 rotor Engima at 1.022727 MHz durning lunch breaks". Membership will be limited, so sign up early. #commodoreoriginal ↗
6 May 2021
Well that doesn’t look anything like a square wave. Bad multiplexer. Saved a Vintage computer from the scrap heap with good tools and a 79 cent chip that is still being manufacturedoriginal ↗
5 May 2021
5 May 2021
10 minute lunchtime progress: Working on more advanced ciphers I need a modulo 32 rotater (wraps 32 bit numbers around by bit at a time). Took a few minutes to wrap my mind around it, but I got it. Step 1 of a bazillion for ChaCha(and AES) complete but I'm happy at the moment #commodore #c64 #cryptooriginal ↗
4 May 2021
Implementing ChaCha… I need 4 eight bit ROLs, but the 6502 is really a 9 bit ROL. I don’t know why it didn’t occur to me to just to a CMP #$80 until now to set the carry before the rotate. Problem solved.original ↗
3 May 2021
My first ever VIC-20 arrived. It seem salvageable, black screen, and you can't beat $25US... I don't own a dead test for a 20 so working on it old school. It was after I desoldered the horrible socket on UE11 that I realized I'm apparently out of 24 pin sockets. #commodoreoriginal ↗
3 May 2021
Late lunch 10 minute progress: Next up is Pontifex from Cryptonomicon. Occurred to me while planning that I better do some card routines first so I don't bite off too much at once. So create a deck and shuffle (requires two different jokers to work) is done. #commodore #c64original ↗
3 May 2021
Today on my operating table is my very reliable Evinrude 50. Just changing the plugs, it’s not even sick or anything.original ↗
2 May 2021
Had a young coder(11) ask me to do my BASIC prime number code program without Simons BASIC so she could do it on Dad’s VIC 20. Here you go Ms. Lisa. I hope you can improve it for us. Sorry about the lack of video capture. I’m on my front porch :) #commodore #vic20original ↗
30 Apr 2021
Tweet sized review of the @retrorewindca carts and harnesses: built solidly and they do what they are supposed to. This is machine number 4 back in service using them. #commodoreoriginal ↗
30 Apr 2021
You haven’t REALLY lived until you try and demonstrate hash collisions using the bug repellent program from Ahoy! Magazine and a type in program called Salvage diver, then cross it with checksums and SHA-256.original ↗
28 Apr 2021
Had quite a few ask about SHA-256 execution times in 6510/6502 Assembly. I'm seeing about 21 jiffies ($15 hex) on average. So 2.857 hashes per second on an unaccelerated Commodore 64. Not too shabby. Imma be Bitcoin rich!! In 50 trillion years.... #commodore #c64 #Cryptooriginal ↗
28 Apr 2021
Getting into the nitty gritty of the crypto series on the Commodore now. I want to demonstrate hash collisions. Only 1Mhz so I'm doing shorter hashes and looking for occurrences of collisions that result in english words.original ↗
27 Apr 2021
25 Apr 2021
This TNC for Raspberry Pi just arrived. Plugged it in and not only did it fail to work, it got so hot I couldn’t touch it. Bleh.original ↗
24 Apr 2021
Brought it with me today in case there was an opportunity to work on it. Had to take cover during heavy rain, so I was prepared to make use of the time AND I fixed the bug. Woot!original ↗
24 Apr 2021
10 minute morning progress before heading out for the day: Tiny bug... this gets all the primes to 2^24 except 3,5,7,11, and 13. And I am really stuck on WHY. Not gonna win any speed records, but it's good demo code anyway. #commodore #c64 #cryptooriginal ↗
24 Apr 2021
I'm actually doing some fishing this weekend, but my other project is to work on the ISS to Commodore config. Step 1 is serial connection to Raspberry Pi which was simple enough #commodore #c64 #Spaceoriginal ↗
23 Apr 2021
Youtube still has me in timeout. Isn't it lovely when they do that and you really have no idea why?original ↗
23 Apr 2021
This took my Python script 207 seconds. My Commodore 64 just crossed the 24 hour mark. I'm hoping it finishes in time to post the article next week! Brute forcing all the primes between 1 and 2^24. But... it's for science! Yeah, that's it!!original ↗
22 Apr 2021
10 minute lunchtime progress: Part 9 is on prime numbers. Following the SLOW BASIC version of this with an Assembly version. Next is printing in decimal and some speed work. Happy at this point thoughoriginal ↗
22 Apr 2021
Since I'm not allowed to comment on YouTube today, here's the YMT/Elysium Bitcoin miner using the Ultimate64 in full turbo mode. Kinda cheating and feels dirty: 26 seconds. My stock Commodore 64 takes 24 minutes.original ↗
22 Apr 2021
The Commodore 64 N.O.O.C.U.L.A.R futbal "project"... I can't say it's the craziest idea I've EVER had, but it sure is fun!original ↗
22 Apr 2021
Gather around the fire kids while Grandpa recounts tales of yesteryear. It was a time where brave men departed on grand adventures in their simulators...original ↗
22 Apr 2021
In case you were wondering, SIMON'S BASIC modulus is 16 bit. Imma need to implement my own to do the next cipher which needs at least 2^24 to match my assembly versionoriginal ↗
21 Apr 2021
21 Apr 2021
15 years after we landed on the moon, a Commodore 64 running BASIC could find the prime numbers between 1 and 10000 in 16 minutes. Same algorithm in Python on a MacBook: 0.04 seconds. Rust: 0.002 seconds. What are you doing with this power? Nothing. Lame.original ↗
20 Apr 2021
This satellite tracker is very cool. You have to hand enter the TLE data which isn't a big deal. It's in BASIC though so just oh so slow ;-) #commodore #c64 #hamradiooriginal ↗
20 Apr 2021
Gonna try to do a Commodore 64 to Commodore 64 Packet session THROUGH the ISS with @K0FFY_Radio. The only thing I was missing was a TNC, so I picked this one up that's a HAT for a Raspberry Pi. If it works, it'll be nice and portable.original ↗
19 Apr 2021
Loving the collaboration between @DarrenFouldsand @8BitShowAndTell so much it’s my office theme today. Even running on a real floppy for the occasion.original ↗
19 Apr 2021
Made a Python, Assembly and BASIC version of RC4 encryption on old computers. Other than questioning my existence on earth for a few days in the process, it went swimmingly!original ↗
19 Apr 2021
Oh. My. God. THIS mistake took me hours to see. HOURS. Okay, NOW I have a working RC4 in Python, Commodore BASIC, and Commodore Assembly. I need a drink.original ↗
17 Apr 2021
RC4 in Assembly is still kicking my butt. This is close but wrong. The python and BASIC versions took and hour, I don't know how long I've been at this version this week, but I still don't have it. Sigh.original ↗
17 Apr 2021
Trying out a thing on Fridays I'm currently calling "The Nostalgia Files". In this first one I reveal my favorite book of all time.original ↗
16 Apr 2021
RC4 in assembly... stuck on the nested loops with a double position swap. This one is making my brain hurt. I’m sure it will seem obvious once I get it but I’m putting it down for the evening.original ↗
15 Apr 2021
15 Apr 2021
10 minute before work progress: Confirmed this is a working RC4 in BASIC with both a standard library and my python version. Assembly version is already about 60% complete. My first real stream cipher... super happy at the moment.original ↗
15 Apr 2021
Am a little stuck with the next few ciphers so I’m turning to Bruce. This book weighs like 19 pounds. Light bedtime reading.original ↗
14 Apr 2021
My controversial stance on modding retro hardware: I'm fine with modern drop in functional equivalents, but I don't want a replacement that implements extra features. I want the original experience extended past the life of some of the componentsoriginal ↗
14 Apr 2021
Way fewer people will read my long form posts than watch a video, but Reason number 27 why I put the bulk of my effort into long form posts on a platform I have full control over:original ↗
14 Apr 2021
I truly love this movie despite its strange plot holes. This novelization actually does a good job of making sense of some parts of the plot the screen version missesoriginal ↗
13 Apr 2021
Package arrived from @FW4511 Is it weird that I really love the box? And I do need more Commodore Notebooks in my lifeoriginal ↗
13 Apr 2021
Visiting with a friend yesterday and he politely said, “This Commodore thing is close to obsession man.” “What do you mean?” I replied. He took my phone from my hand and turned it over. Okay, maybe just a little…original ↗
13 Apr 2021
12 Apr 2021
I happen to have a RedBird TD2 AND a mobile Commodore 64 running Kennedy Approach which is an Air Traffic Control game. How cool would it be to make a game that interfaces with the RedBird? I have an idea for a data interface…original ↗
12 Apr 2021
Working at the airport office today but I don’t want to slow down. Mobile 64 rig for the win. The next cipher to tackle is RC4. This one might take more brain cells than I actually possess.original ↗
12 Apr 2021
Stuff to play with and then review from DIY Chris came today. Gal PLA, 4146 RAM tester, flash-able Kernal/BASIC/character rom chip and an adapter for these types of chips for my 866 programmer.original ↗
9 Apr 2021
My 128 trouble maker is on the mend. I’m short two 4146s to test completely but mail should bring them soon. Socketed now and even recapped a lot of the Ceramics too. Lower checks out anyway :)original ↗
9 Apr 2021
Turns out serial cable was attached to a Keyspan. Double win and it only took me a half hour to find. Now who’s gonna clean up this mess?original ↗
9 Apr 2021
Desoldering 16 memory chips with 16 pins each is NOT something one should do when feeling impatient. I got them all without a single lifted pad. This 128 will live to fight another day.original ↗
6 Apr 2021
The next two parts of the Cipher series are on Symmetrical Encryption and the algorithms take quite a long time to run at 1Mhz. Having a portable rig has been really nice.original ↗
3 Apr 2021
After listening to an episode of @GUp80s with @DarrenFoulds and @8BitShowAndTell I've gotten back into one of my favorite games: Mastermind. So simple, but it's a good conference call thing. There's a great port of the IBM version to the 64.original ↗
3 Apr 2021
My childhood best friend has never really been on social media and checks email every other week. I asked his wife the best way to chat with him. He overheard the conversation on the phone and sarcastically said “mail me a floppy”. I thought, well okay, 3.5 or 5.25? #thatwaseasyoriginal ↗
3 Apr 2021
10 Minute lunchtime progress: My 6502 experiment board is fully working. Love the way this turned out. #commodoreoriginal ↗
2 Apr 2021
2 Apr 2021
I haven’t done HAM radio stuff in a couple years now, but this combination may rekindle this interest. My call sign is N4LNX #commodore #c64 #hamradiooriginal ↗
1 Apr 2021
Off on a pre workout tangent this morning. Decided to dump the SID output for 16Mb to look for evidence of that 23 bit LFSR. I can't actually find repeats at all and this should be 24 bits. #commodore #c64original ↗
1 Apr 2021
10 minute evening progress: This is moved over from the breadboard onto a compact (and neat) PCB. Last thing is the Arduino HAT daughterboard, but I'm thrilled with this at the moment. How it started, how it's going. It's got #commodore bones anyway ;-) 6502 is my favorite.original ↗
31 Mar 2021
10 minute lunchtime progress: Making headway in Cipher Series Part 6 where we talk about the magic of XOR in data integrity and then encryption. #commodore #c64 #retro #securityoriginal ↗
30 Mar 2021
Strange flickering after I installed the JiffyDOS mod on my 128. Quite uncharacteristic of me, I did not inspect this switch carefully. Something seems off… :)original ↗
30 Mar 2021
Almost finished with the 6502 board while listening to @GUp80s read choose your own adventure stories. Missing a latch switch. Where’s a Radio Shack when you need one?original ↗
29 Mar 2021
The c0pperdragon mod has a default pallet that's just not my cuppa… luckily it's editable. How it started vs how it's going. MUCH better.original ↗
29 Mar 2021
Recording a video response to the @8BitShowAndTell Easter egg(s) on the vinyl album video. I think I need a bigger desk. Let’s sell the house! #commodore #c64original ↗
28 Mar 2021
28 Mar 2021
Okay, how long do you think this rig will run on an old 20 amp hour battery with the screen at full brightness? I want the 4 hour square. I gave it some work to do to keep it from sitting idle.original ↗
27 Mar 2021
Cannibalizing an Easy Flash case for @adrianglz64 Snappy cart. The wifi module even fits. Time to get to work on this thing.original ↗
27 Mar 2021
Wyze watch came today. On the left: $20, on the right: $420. One of them will make it almost 24 hours on a charge. The other one will make it more than a week.original ↗
27 Mar 2021
Still waffling on which machine to use in this. If I go with "TheC64" from @THEC64_RGL it's 5V like the monitor I'm using so an off the shelf phone battery makes this completely wireless. To use the Ultimate 64 I do have these voltage converters that would work.original ↗
27 Mar 2021
Okay, I got both @8BitShowAndTell Easter eggs on the prodigal album. Finally. Yes, it’s what I did on a Friday evening (also my birthday). My wife helped. Took… a while and a whole legal pad page of notes to get. Well played Sir Robin. Video on it coming soon.original ↗
27 Mar 2021
If you REALLY want to get into the weeds on how I figured out the @8BitShowAndTell Easter Egg(s) inside the Easter Egg on a 35 Year old album on a 35 year old computer then you're in luck, this video is for you!original ↗
26 Mar 2021
Still iterating on the portable C64 design. I’ve got a list of changes to make, but field testing today has been successful. #commodore #c64original ↗
25 Mar 2021
Very cool delivery from @gregnacu, Commodore compatible controller with switchable fire button function and Chicken logo patches. Nice!original ↗
24 Mar 2021
Well it arrived. Time to work on figuring out the easter egg @8BitShowAndTell put INSIDE the easter egg on this album. I don't have a direct input to a C64, so step one is getting this program on tape. Where IS my tape recorder anyway?original ↗
24 Mar 2021
Huh, weekend todo list is done. That’s… strange. Stretch goal is to get my pack base weight under 13 pounds.original ↗
21 Mar 2021
21 Mar 2021
Considering ditching TheC64 for this and going with the Ultimate64. I have these two cases for it. Both will fit. A real C64 isn’t practical for power and fitting a cartridge in the back.original ↗
20 Mar 2021
New to me 64C keyboard. Moving my Ultimate into a 64C case and want the keyboard to match.original ↗
20 Mar 2021
Working on the Snappy this morning for @adrianglz64 , why do I like this weird character thing while flashing it? Also, my capture device does an excellent job picking up the jail bars on this particular machine ;-)original ↗
20 Mar 2021
Fits in the case. Monitor and TheC64 are 5V. Both run off of a single split wall plug or a 10Ah battery. Need to design/3D print brackets(less foam please) and buy a right-angle HDMI connector. I can visit @gregnacu and his Ultimate portable in a cafe soon #commodore #c64original ↗
19 Mar 2021
I've been trying to figure out what to do with my "TheC64". I have this pelican 1490 case and a 14" very thin monitor that will fit in the lid. I need some kind of mechanism to raise it up when it's open. Hmmm... #commodore #c64original ↗
19 Mar 2021
For the first time in weeks I don't know what to make next. Blinking cursor is taunting me... #commodore #c64original ↗
19 Mar 2021
17 Mar 2021