Two Stop Bits | ddingus's comments

ddingus 680 days ago | parent | on: The 6502/65C02/65C816 instruction set decoded
What a great resource!
I know a lot about these chips and learned something new:
There is a single cycle NOP on the 65C02! Spiffy!
---Excerpt Below---
There aren't really any undocumented instructions on the 65C02--any instructions not listed above are documented as performing no operation.
However, these alternate NOPs are not created equal. Some have one- or two-byte operands (which they don't do anything with), and they take different amounts of time to execute.
Instruction Bytes Cycles
```
     xxxxxx10	2	2
     xxxxxx11	1	1
     01000100	2	3
     x1x10100	2	4
     01011100	3	8
     11x11100	3	4
```
ddingus 680 days ago | parent | on: PaperCart – Make an Atari 2600 that plays QR codes
I love this project! Brilliant!
ddingus 697 days ago | parent | on: Happy Holidays Everyone!
Thanks to everyone here for being here.
I like everything so far and hope it can grow and thrive!
ddingus 705 days ago | parent | on: Missile Command Deep Dive
This is a top notch analysis!
ddingus 707 days ago | parent | on: Native PC port of Nintendo's Game Boy Zelda is pre...
404...
ddingus 710 days ago | parent | on: 6502 Integer Multiplication - which is best?
I have almost always found a look up table, plus specialized routines to be the best overall.
Like the author says, it is the speed vs memory tradeoff in action.
When I do not care about speed, compact routines that yield the answer to as many, or even all my use cases, are best. The memory ends up being put to a better use.
Otherwise, I generally need specific multiplies and code for those best I can.
ddingus 714 days ago | parent | on: 6502 - RISC or CISC cpu
CISC for sure. Now, compared to a 6809...
ddingus 718 days ago | parent | on: A Graphical OS for the Atari 8-bit
This project has been years in development.
I am on mobile, but the development logs on Atariage.com are a great read.
ddingus 719 days ago | parent | on: Dodo: 6502 Portable Game System
I like this kit. Too bad the seller is on a break.
ddingus 724 days ago | parent | on: Raster CRT Typography (According to DEC)
It is!
Phosphors varied considerably too. Faster phosphors were generally avoided due to the need for low refresh rates and or interlaced display lines.
An older black and white television, for example, used slower phosphors in order to minimize the impact of interlaced images.
Similar phosphors in green and amber, to my eye a bit slower, pretty much eliminated flicker at 50hz / 60hz. These phosphors did not fatigue users much.
Newer, color displays came with faster phosphors!
Fonts look very different because the response curves are different as this great piece covers well.
More