CoreDocArchimedes - mist-devel/mist-board GitHub Wiki

Introduction

This page has operating instructions for the Acorn Archimedes core by Stephen Leary.

  1. Basic internals are implemented.
  2. Two floppy disks with read/write support
  3. IDE interface with two (master/slave) drive support
  4. Sound support added but may not work in all situations.
  5. The core emulates an A3000 type machine with 4 MiB RAM with an ARM2a with caches disabled for now (has an A3010 style joystick interface).
  6. Core runs at ~91% of an ARM2 @ 8Mhz when using VGA Modes.
  7. Some games now run. Expect issues.

If someone has an MMC/SD card driver/podule then please mention it in the forums so it can be include it in the core.

Links

Installation

Make sure to upgrade to the latest MiST firmware first (200516 or later).

Copy the Archimedes core into the root folder of the SD card. To make the MiST start with this core, rename it to core.rbf.

Copy a version of the RISC OS ROM into the root folder, renaming it to riscos.rom. Emulators sometimes come with four files comprising the ROM image, see here how to join these files into the one file needed by the Archimedes core and how to save the ROM from a real machine.

Floppy disk images

The current version supports two floppy drives. Floppy disk images ADF format and of exactly 819200 bytes in size are currently required. This is the most common format for the Acorn Archimedes. Note that this is not identical to Amiga .ADF format.

Images named floppy0.adf and floppy1.adf are auto-inserted into the floppy disk drives on startup. Other images can be selected via the on-screen-display (OSD) which can be opened using the Print Screen key.

Hard disk images

The core supports the RISC Developments IDE interface podule. This allows to attach two IDE hard disk images to the core. They should be put to the root of the SD Card, and should me named as archie1.hdf and archie2.hdf. To use the images, appropriate CMOS settings should be applied. They can be found in the IDE interface manual. You can export the CMOS RAM from an emulator (Arculator's CMOS.RAM files are OK), or just save it in the OSD menu to the SD Card.

There are some immediately usable files in the binaries folder:

OSD Menu

If the ROM is recognized the core should boot into RISC OS. Press Print Screen to open the OSD menu (the MIST usual F12 is used by the Archimedes).

  • Floppy 0: Choose the floppy disk images to use for floppy 0
  • Floppy 1: Choose the floppy disk images to use for floppy 1
  • OS ROM: Choose the RISC OS rom to use
  • CMOS RAM: A 256 byte CMOS RAM file to use
  • Save CMOS RAM: saves the current contents of the CMOS ram on the SD Card
  • Firmware & Core: Change MiST core or upgrade firmware
  • Save config: Save current config for next boot

You can move to other pages of settings by pressing the right arrow key.

Notes

  • Compatible versions of RISC OS are RISC OS 2, RISC OS 3.10, RISC OS 3.11 and RISC OS 3.19
  • Only RISC OS 3.1x supports (S)VGA compatible output for all screen modes.
  • Older RISC OS 2.xx versions will need a VGA to SCART cable at present (or use the built-in scandoubler for VGA screens).
  • To use RGB SCART, keep tapping the 0 numpad key at boot (or set up the CMOS RAM for an appropriate screen mode, and save it).

License notes

This core uses the Amber CPU core from OpenCores which is LGPL. The core itself is dual licensed LGPL/BSD.

Desktop videos

RISC OS links