Tag: B256

Debugging 6502 Assembly Doesn’t Have to be Awful – RetroChallenge 2018/04 – Update #9

I do not remember how I debugged BASIC programs back in the 80s. To be honest, I do not even want to remember. I’m sure it was convoluted, ugly, and painful. You know what’s really nice? Modern development environments where you can step through your program, statement by statement, watch the variables change, maybe even change some yourself as you go,…

Setting Up a Modern Development Environment for 6502/6509/6510/8502 Assembly Language – RetroChallenge 2018/04 – Update #8

If you are following along from the last update, you now have assembled the pieces you need to start programming in 650x Assembly language. Since my RetroChallenge is focused on the Commodore CBM II (“B Series”) machines, I am going to be showing how to set a development environment for that machine. But the same environment will work just as…

The Only Thing We Have to Fear, is Assembly Itself – RetroChallenge 2018/04 – Update #7

  Assembly language: the very name strikes fear into the hearts of retro-computing oriented nerds everywhere. “I used to program my (Atari|Commodore|TI99|Apple|ZX Spectrum) in BASIC, and I always meant to do something in Assembly, but… ” If that sounds familiar to me, then this is the blog for you! Or rather, this is about the 100th blog for you, because…

CBM II Series: You Get Nothing! – RetroChallenge 2018/04 – Update #5

In the last update, we discovered that the empty socket at highlighted item #2 was intended to hold the character ROM chip. In this update, I’m going to cover tracking down the contents of that ROM chip, the equipment we’ll need to replace the missing chip, and the basics of EPROM burning. Along the way, I’ll cover a couple more…

Programming a Dinosaur is More Fun than Describing One – RetroChallenge 2018/04 – Update #4

Ok, I admit it: I lost a bit of focus the last few days. I should have been buckling down and describing the circuit board more, and well, working on getting the machine up and running. Instead I have been using my non-work, non-family time to… … program. In my defense, writing is hard work. “Programming is hard, too!”, you…

CPUs: The More the Merrier? – RetroChallenge 2018/04 – Update #3

You know those jokes that begin “You might be a redneck if you”? Here’s a Jack Tramiel version: “You might be in Commodore marketing if your boss told you to sell more CPUs, so you had the engineers cram 2-3 in every computer.” Thanks folks, I’ll be here all week… Despite some confusing early names, the Commodore B-series is not, in…

Not Your Daddy’s 128 – RetroChallenge 2018/04 – Update #1

Ah, Retro Challenge… The most optimistic challenge ever created: get a bunch of people to complete a project about old computers, in one month. Let’s set aside the question of how likely it is that your average retro tinkerer actually completes any of the 20+ “projects” they inevitably have going. (Hint: they’re called “tinkers”, not “gods of the retroverse” for a…