Monitor progress and thoughts on the 68000 ISA

The machine-code monitor for my MINI000 68000 SBC is coming along nicely. It’s been great fun and an excellent introduction to writing 68000 assembly. Command processing consists of the following steps: Read a line of text from the serial port. Parse the line into command and argument portions. Locate the command from the set available. This will result in a… Read more »

Adding a C library to the 68000 SBC

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There are more than a few different choices of C library for running on small systems. Some candidate C libraries for the MINI000 board include: Newlib is an extremely popular choice for small systems. It is relatively complete. Not quite complete enough for a modern desktop Unix system, but almost. It specifically targets bare-bones (AKA freestanding) 68K systems, and allows… Read more »

MPCNC “finished” and progress with the 68000 SBC

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The MPCNC is now ready to be used in anger. It took longer then I’d have liked but it’s all ready for serious cutting, albeit in wood: Making the spoil-board up was a bit of a mission, mostly because I’m completely new to this kind of thing. I started with a 600mm by 1220mm by 18mm thick piece of MDF…. Read more »

First cuts from the MPCNC

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Working on the MPCNC has been a bit of a background project. It’s hard to believe I started printing the parts for it about four months ago. Here is a little about the MPCNC for some context. The project is the brainchild of “Ryan” at v1engineering.com. It  is a set of 3D printable part designs, given away freely, and other… Read more »

68000 SBC bring up

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Five MINI000 boards arrived just after Christmas. Annoyingly I got stung for the import duty, but fair enough. They were still very cheap! The quality looks fantastic, though its hard to tell from a camera-phone shot: The following was done over the course of a few weeks. Unlike the MAXI09 board bringup, I took my time and found I enjoyed… Read more »

Designing a 68000 SBC

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I have decided to be a little brave and have opted to build a 68000 SBC instead of one based off a 68008. Specification wise it is similar to the 68020 design: 68000 clocked at 16MHz 1MB static RAM (2 x AS6C4008 (PDF)) 64KB EEPROM (2 x AT28C256 (PDF)) DUART (XR88C681 or, in its place, a SC2681 (PDF))) Expansion connector… Read more »

Being sensible: a 68008 computer on breadboard

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After writing about building a 68020 computer I feel slightly silly for going back on my word: I have built up a 68008-based computer on breadboard. For one thing going right to a 68020 felt a bit like I’d be missing out; the pleasure is in exploring not the end result. I’d have left out on the other MPUs in… Read more »

Design of a 68020-based SBC

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My interest in the 68000 family of MPUs stems from two things: it’s use in my all time favourite computer, the Amiga. And the fact that it’s generally considered a very clean design compared to its then main competition. Not that this is a high bar; anything prior to the 386 is dreadful and the later CPUs are not much… Read more »