I went ahead and pushed my initial commit to the ROL GitHub repositories for hardware and software. The hardware repository contains the schematic of the current state of the hardware, along with the component library I’ve made, and my modified version of Ben Eater’s Arduino bus monitor. My modifications include the disassembly of the code… Continue reading Github Initial Commit
Now that I have ROL working and have been doing some programming, I have decided to modify the memory map. For one thing, I don’t need two EEPROMs. As mentioned previously, I am going to have the EEPROM code only run long enough to load the actual system code from a storage device into faster… Continue reading New Memory Map
ROL’s current memory map supports two 8K EEPROMS for its software. So far, I’ve only been using ROM 0 at address $e000 to $ffff and ROM 1, at $c000 to $dfff, has been stuck in the breadboard, filled with $EAs (the 6502 NOP). The chips I’m using are some AT28HC64Bs. These chips are 150ns. With… Continue reading The EEPROM
After getting the Jump Bug straightened out, I decided to double-check the 65c22s and make sure they worked as expected and then try to get the LCD display working. I tested all four 65c22s by hooking both ports up to an LED bar and then sending a bit pattern to each one. After they all… Continue reading I AM ROL
In the last post, I mentioned a bug I was working on that would cause all 0s to appear on the data bus after a JSR instruction was executed. This bug turned out to be way more elusive and time-sinking than it should have been. When I had finished wiring up the basic system (EEPROMs,… Continue reading The Jump Bug
At some point, around 2017 or so, I read something about someone who was putting together a computer based on a 6502 microprocessor. It piqued my interest. I started seeing several other such projects popping up. I did more research, mostly at 6502.org. Eventually, I designed my own system and made a schematic. I named… Continue reading ROL Lives
There used to be an employee at the company where I currently work. He was on the same team as me, but he left before I got there. I’m not sure, I may have been his replacement. Anyway, my coworkers at the time had worked with him. They told me when he left, they found… Continue reading Hello World!