Github Initial Commit

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

The EEPROM

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

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I AM ROL

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

The Jump Bug

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

ROL Lives

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

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