I’ve added support for the 6502 and 65C02 microprocessors to my db65xx VS Code debugging extension. Here is an image of me debugging my 65C02-based Forth operating system.
65816: Testing the 32-bit Floating Point Package with the VS Code db65xx Debugging Extension
A reader recently asked me about some troubles he was having getting my 32-bit floating point package up and running. I thought it would be a great test for my new VS Code 65816 debugging extension. With just a few edits to the test program the reader was using, I was up and running in …
65816: VS Code Debugging Extension Available
In my last post I discussed developing a debugging extension for VS Code for the 65816. It was pretty easy to get something up and going in a couple of days, but polishing it took a bit longer. It’s now available in the Visual Studio Marketplace and for modification at my GitHub, along with an …
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65816: Debugging Code
I haven’t written much about debugging yet, but tools to help debug my code have been essential to my system development. I started out with the simple Ben Eater 6502 build where debugging consisted of repeating a cycle of write code, assemble and burn it to an EEPROM, and test the system for proper operation, …
65816: Coding – To Optimize or Not
As I was working on my 32-bit floating-point package (GitHub) I noticed some opportunities to optimize the code. For example, scale10, used while converting strings into floating-point values, uses the package’s 32-bit routines to multiply and divide by 10. For example, to scale up by 10 we load 10 to the floating-point stack and call …
65816: 32-bit Floating-point Package Available
I wrote in my previous post about testing my 32-bit floating-point package on a Mandelbrot plot. Paying forward Marco’s original 128-bit package contribution, I’ve made my 32-bit package available on my GitHub. It’s still a work in progress with limited functionality. But it’s still enough to handle Mandelbrot which was my original goal. Function Stack …
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65816: Floating Point – Finding a Balance Between Speed and Precision
I first got interested in the 65816 because of floating=point support. I had just finished porting Cosmic Conquest, an old text-based strategy game, to my 6502 system and was looking for other old games to port. I remembered an old text-based Star Trek game but on tracking it down discovered that it used floating point. …
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65816 Emulator: Threading in Python Very Slow
I haven’t talked much about my 65816 emulator but it’s been essential in porting my 6502 Forth over to my new 65816 build. The slowdown I mentioned in my post 6502: Coding – Just because it works doesn’t mean it’s correct though was becoming annoying. Starting up my Forth operating system in the emulator took …
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65816: Build 4 – Revisiting PLD Coding
In a long postscript to 65816: Build 4 – Adding Expanded RAM I discussed some alternatives I tried to achieve the following memory map in my ATF22V10C PLD. There’s nothing magical about this memory map, it’s just something I wanted to try, for reasons I’ll discuss in a operating system post if I ever get …
65816: Build 4 – Adding Expanded RAM
I’ve mentioned previously having trouble getting WINCUPL to create the following memory map: I figured that since I was expanding ROM, I might as well give myself a full 32k of RAM. WINCUPL didn’t like that though, giving me an error that it didn’t have enough pterms for my ROM_CS pin. I took the easy …