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
RSS- 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
- In case you're one of THOSE people who was just sitting there thinking "what ARE the startup values in the VIC chip registers on a VIC-20?" Well, you're in luck. #commodore
- Gonna have to build some sort of test bench jig if I’m going to have 32 leads connected to the VIC chip at once without it being a wire hot mess. Good news it the DreamSourceLab 32 channel analyzer arrived and took about 60 seconds to set up. #commodore
- VIC's Revenge, the drop-in replacement for the VIC-20 VIC chip Part 1 · imapenguin
- Well this is good, turns out I do know how to create a B&W PAL (and NTSC) Composite/S-Video signal from scratch. My timings aren't quite right, but it's close. Good first crack though. #commodore #VIC20hacking #learnallthethings
- Package delivered from
- Actually read the manual for my scope yesterday. Turns out it’s crazy easy to trigger on a PAL horizontal scan line number. On 110 here you can clearly see the blinking cursor. Turns out RTFM is a good idea after all. #commodore
- Yes, even the KIM-1 (clone) can count to a couple quintillion with ease ;-) #commodore
- I read this cover to cover sitting by the river yesterday. Can’t recommend it enough.
- Current situation
- I think I've decided on a working codename. Logic analyzer ordered and shipped. I'm shooting for a working version in a year.
- 64 Bit Addition and Products on Commodore: The Wheat and Chessboard problem · imapenguin
- 8 Bit processors can count to 18 Quintillion just fine. "Wheat and chessboard problem" in 6502/10 Assembly for my "learn something every day" task. #commodore
- I tell myself I have some lofty career aspirations to justify my deep dive into learning to code FPGAs this year. But I know deep down it’s so I can try making drop in replacements for things like this, which I found in my stash. It tests good in my only NTSC VIC 20 #commodore