Tag: CBM 720
This is my 10th, and presumably final RetroChallenge update: tomorrow is the end of the contest. Most people would say “Hey, you were crazy to set that goal in the first place, let alone start with only a day left.” Ah, what do they know? I just a game design, and write some code. Sure, I only started learning assembly…
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,…
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…
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…
A reminder to the hoards of fans who have been following along with bated breath each day for updates on this project: my goal for this, my first RetroChallenge, is to get a CBM 710 into working state. My super ambitious goal would be to also write an assembly language program and get it running on the CBM 710. My…
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…
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…
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…
You Say Tomato, I say C128-40! Before I dive into the innards of my CBM 710D and we go spelunking for missing chips, I want to introduce the other computers in the B series. There were actually three main variants of this line of computers: The high-profile version with the integrated monitor. The video chip in the high profile machines…
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…
