I write about the past, present, and future of technology across three sites. imapenguin.com explores retro computing and programming fundamentals, milkcrunch.com covers modern software development and engineering culture, and evadot.com examines commercial spaceflight and the new space movement.
Posts
- Almost primes with TinyBASIC on the KIM-1 clone: PAL-1 · imapenguin
- My new favorite browser plugin. Your brain, like your body, is what you feed it. Don't let others (or algorithms) feed it for you.
- I was just looking at my logbook and need a couple approaches for IFR currency. Do you think the FAA will accept this VIC-20 Simulator? It works surprisingly well. I'm just saying FAA, could be good enough. #commodore
- One of my 2022 goals is to finish both of these including typing and understanding (as best I can)every example on both the C64 and VIC-20. Just finished the BASIC book, so slightly ahead of schedule. On to the Kernal book. I blame @8BitShowAndTell for this one :) #commodore
- I know you were just sitting there thinking "What IS the clock divider setup to run a VIC-20 without needing the onboard clock circuit working? 1.10822Mhz is pretty specific." Well today is your lucky day. #vicsrevenge #commodore
- Just thinking it would be nice to be able to read VIC-20 video RAM in real time. Then I remembered I have a Romulator (for a year, never used). Unfortunately the vram isn't implemented yet, but I can still dump the rest of memory to a file which is nice. #commodore #vicsrevenge
- So many Mega 65 posts. This is like a Mega 66 so there. #commodore
- Picked up a DM-42. I blame @svenpetersen191 for this one. I resisted the purchase as long as I could. Amazing how it’s almost exactly the same size as my very well worn HP-42
- Two more boards donated to the VIC project arrived today. Awesome. #commodore
- I don’t think I can get away with NOT level shifting from 3.3 to 5v on a VIC-20. Probably not… But there sure are nice and cheap tools for things these days. Need a completely configurable 3 output 8khz to 160Mhz clock generator? That’ll be 6 whole dollars please.
- Beautiful VIC-20 board donated by the amazing @cmherndon79 for the 6560/1 project. This board will be the one that gets the prototype board for testing. #commodore #vicsrevenge
- Well that.. DEFINITELY looks like a Composite video signal (PAL). Woot! Now on to the interlace math and the NTSC version. Urg, do we REALLY need interlacing? VGA is SO much easier... #commodore #vicsrevenge
- Why spend 10 seconds sketching a timing diagram for VIC-20 video output signals when you can spend 20 minutes doing it on an actual VIC-20? Happy almost Friday ;) #commodore #vicsrevenge
- Didn’t get a chance to post this earlier (work), but the next step in the VIC 6560/1 project is to create composite out on pins 2 and 3. This is at least starting to look something like a composite luma signal, kinda. One step at a time. Back to day job! #commodore #vicsrevenge
- First time I've used this modeling software and was impressed. Working out NTSC Luminance timing logic is a big help after just a couple mins. 100Mhz clock on the FPGA so we can just count nanoseconds. Can export to Verilog after simulation. Most excellent #commodore #vicsrevenge
- Rated at 11.5 and puts out 11.9 under no load. Not bad for 41 years old. #commodore
- Progress this morning before the day job kicks in: I have an externally clocked VIC-20! Internal timing being driven my an ICE40 FPGA. It’s a couple cycles slow but getting there. Now to start on video signals. The math makes my brain hurt. More coffee #commodore #vicsrevenge
- One of the very strange quirks about NTSC and PAL Composite video on VIC-20s is the half frame interlacing and the offset odd numbers you have to "count". So how long exactly is each frame SUPPOSED to be… #commodore #vicsrevenge
- Next step in the #vicsrevenge project is to create the two out of phase clocks that the CPU uses. This 6561 outputs pretty close to the spec. #commodore
- I do buy legit copies of JiffyDOS from Jim B and even buy the official switcher when I need them. Sure I can burn my own with pirated copies, but a legit license is $8 whole dollars. Cmon man. #commodore