[Path_To_RetroAssembler]/retroassembler.exe -d cegmon.bin cegmonDis.asm The SD Card uses the following FPGA resources: The overall resources show 98% of the logic is used. It might be worthwhile to free up some of the logic elements so it's not...
I've loved the (on-line GodBolt) Compiler Explorer project for a while now. It lets you type code in one window and see it compiled to assembly language in another window. There's a Compiler Explorer site which does 68k cross...
One of the things that's become an increasing problem on this project is the MC68901 Multi Function Peripheral. Way back when I started this project (actually when I ordered the very first MC68010 for it!) I ordered a 68901, almost on a whim, as...
I'm about to start assembling the first revision of the Motorola 68000 motherboard. This revision, rev1 (I start my revisions at rev0), includes a few fixes for minor problems in the prototype. None of these problems were show-stoppers, and I was able...
The board is now fully assembled:Notice the adapter I had to make to correct my design mistake with the RAM address bus. Apart from that It's very satisfying to see the finished board, as this is my first real PCB design.But does it actually work?To...
I was going to open up my NEO unit to see what's inside. But, fortunately, people have already done that. There is a CR2032 coin-cell inside that serves as backup to retain SRAM while the AA batteries are removed. Some power users have opened their units...
CP/M is a well known operating system in 1970's and 1980's. It was designed for many different processor family, e.g., Z80, 808x, 68000 and others. Running CP/M is the end goal for many of the processors prototyped with G8PP because that...
The minimal 68030 computer has 512K of RAM and a simple serial port. Here is the memory map of stage 2 68030 computer:RAM 0x0-0x7FFFFSerial port transmit/receive: 0xFFFFF000Serial port status 0xFFFFF001 Bit 0 is TxEmpty, transmit buffer empty...
[Edit: I've added a schematic for this circuit at the bottom of the log!] I'm not sure what exactly I was thinking of when I wrote the previous log about handing the /BOOT line, but it's completely and utterly wrong. Luckily, I realised this when actually...
I hadn't looked on to it for years (no time, creating an extra room in the attic and so on), but it kept itching... On the other hand it seems so strange fiddling around with old hardware, a simple ESP32 has more capabilities and speed than a 68k will...
IntroductionIn this log, I'll explain in detail how this single-board computer works.8 bits bus onlyThe 68020/68030 have dynamic buses; this means that they are not fixed to 32 bits. A 68020 board can have 32 bits RAM, 16 bits ROM, and 8 bits IO. Of...
This is a short log[*] describing the 16-bit expansion card interface in the 68000 system. I've deliberately kept the design of this interface as simple as possible, in order to make it easy and quick to build expansion cards. I know I could have implemented...
This project started with me seeing an MC 68000 on a breadboard blinking an LED. It seems this is a rite of passage for 68k builds. Although a little bit of a challenge at the time, it's a great way of getting to know your way around the physical package...
Installable binary files to the AlphaSmart device have an extension ".os3kapp". Several of these come with the official AlphaSmart NEO Manager software - the tool used to link a NEO to PC and perform software updates, copy files, manage classroom activities,...
In the last log I got the toolchain working on my Raspberry Pi to cross compile code for the 68K CPU. In this log, I will try and assemble the TUTOR 1.3 code using the toolchain. I am using FileZilla to transfer the file to the Raspberry Pi. Here...