106 Results for "68000"

Loading the Monitor into the FPGA ROM
Log from Retro 68000 CPU in an FPGA
The HEX file initialization in Quartus is not well behaved. When you make 8-bit ROMs it works fine. When you make a 16-bit wide ROM it doesn't load corrected. That seems to be because the HEX loader in Quartus sees the file addresses as the offset to...

SDRAM Working in a Different Context
Log from Retro 68000 CPU in an FPGA
There's an interesting project from 2014 called TG68 Experiments at Retro Ramblings (AMR) to create a 68000 CPU that uses the SDRAM on these inexpensive FPGA cards. The project starts with the 68K same core (TG68) I've been using by Tobias...

Moving Past Memory Issues
Log from Mackerel 68k Computer
After spending many hours building various combinations of kernel versions and configurations, I've finally got Mackerel progressing past the memory initialization errors. I tried 6 six different kernels, multiple compiler versions, and every config...

Theory of a CPU module
Log from MC68000 Computer
Compared to the 8080, the Z80, the 6809, 6502, and all the other 8-bit microprocessors used in boxxen of yore, the CPU I’m using for this project - the Motorola 68000 is both extremely powerful and extraordinarily complex. The power comes from a huge...

Theory of RAM and ROM modules
Log from MC68000 Computer
Although it might make sense to start this project by building a CPU module first, I decided it would make more sense to start with the memory for this system. This serves two purposes: as an explanation of how the 68000's memory-mapped I/O works, and...

STEbus and VMEbus boards I am aware of.
Log from STEbus
Here are the STEbus and VMEbus boards I am aware of. I have some of them, and some documentation. Let me know which ones interest you. Code Name Title (Main features) [notes]J004 ARC8000 VMEbus Z8000J020 SC88 80188 (80188 and dynamic RAM)J023 SCPUA...

Fuzix 0.3 Release
Log from Fuzix OS
Fuzix 0.3 Release Notes Fuzix 0.3 is the third major release of the Fuzix OS. This release has mostlybeen focussed upon kernel improvements and supporting more platforms,particularly ZX Spectrum derived ones. The 68000 code base is now usablebut not...

Software Build Toolchain
Log from 68K CPU with Frame Buffer on FPGA
Assembler vasm - AssemblerBuilt from source on Linux. C Compiler GCC - 68k Cross-compilerBuilt from source on Linux Build environment Run in VirtualBox under Windows. Example Software Example Software GitHub Makefile for Rectangles code ARCH = 68000...

Random post
Log from Merlin
I tried to use the existing RND function in ehBasic. It left a bit to be desired, so I thought I'd use the Gameduino Library random function. It's a good example on how to merge the basic code, through assembler and out to a C function.I have a C wrapper...

More interrupts
Log from Merlin
So auto-vector interrupts are now available. A tweak to the monitor switches on interrupts by moving $2000 to the stack register.The 68000 has 7 auto-vectored interrupts which are located at specific addresses in the memory:#define int1 0x64 #define...

FPGA VGA Card V2
Log from Y Ddraig - My 68000 Computer
While I already have a VGA card that I built previously, I have started working on a new version as well. Part of the reason for the new board was to increase the number of colors displayed. The old version used 12-bit color (4,4,4) to have 4096 colors...

Step 4: Step-By-Step
Log from Yet Another 68k Homebrew Computer
I'm slowly moving forward. Trying to debug the ROM connection I achieved partial success. Still don't understand why my program didn't run like expected, suspect that bread board becoming "a bit" noisy running on 4 mHz speed, but slowing things down...

Mise en place (RC 2022/10)
Log from Flounder Z180 Computer
I've been kicking around the idea of building a single-board computer around the Zilog Z180 for a while. It fits nicely between my Herring 6502 and Mackerel 68000 projects. It's got the simplicity of an 8-bit processor with a few more bells and whistles...

Update and Working Monitor Over Serial
Log from MC68000 Computer
So a lot has changed since my last update on here, I've redone the address decoding to use a 74138 3-8 line decoder to allow me to partition the address space. I've added some status LEDs to help show the state the computer is sitting in, so I don't...

The Address Decoder
Log from rosco_m68k
Address decoding for the m68k is a bit more involved than for most (all?) of the 8-bit CPUs that were around at the same time, and so requires a bit more careful design. The specific things that make it complicated are:The larger (16MB) address spaceThe...

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