Oric-1 / Oric Atmos for MiSTer Platform

Original Read.Me for MiST. Not all info is releavant to MiSTer.

Oric 48K in MiST and SiDi FPGA

Oric-1 and Oric Atmos re-implementation on a modern FPGA.

Background:

There is one version made and ported by Gehstock at GitHub, but it's far from a functional Oric. Gehstock's version for MiST board was realeased as a proof of concept with only 32KB RAM (no Oric existed with that memory, only 16K ,48K and 64K)(64KB is real RAM) so there were errors managing HIRES mode) and no way to load audio tapes and lots of graphics errors on screen.

What can you expect from Oric 48K in MiST and SiDi FPGA ?

This project began in november 2019 with the aim to preserve the Oric's computer family into FPGA.

Actually Oric 1, Oric Atmos and Microdisc are fully functional.

• ULA HCS10017.
• VIA 6522.
• CPU 6502.
• Full 64KB of RAM.
• Keyboard managed by GI-8912.
• Sound (AY-3-8910).
• Switchable ROM (between 1.1a ATMOS version and 1.0 ORIC 1 version).
• Tape loading working (via audio cable on the RX pin).
• Oric Microdisc implementation vía CUMULUS
• Disc Read / Write operations fully supported with EDSK (The same as Amstrad CPC) format.
• Disc Sedoric/OricDOS Operating System Loading fully working

TODO

• Debugging, checking for possible bugs at video and improving the core.

KNOWN BUGS

• Issue loading files on multipart dsks; i.e. programs using CLOAD to load in other data from the dsk.

..if you find others, let us know, please.

HOW TO USE AN ORIC 1 & ATMOS WITH MiST, MiSTica and SiDi FPGA boards.

• Create a directory called ORIC at your sd's root and put inside the disc images to work on

  • Once the core is launched:

  Keyboard Shorcuts:

  • F10 - NMI button, acts like original ORIC NMI
  • F11 - Reset. Use F11 to reboot once a DSK is selected at OSD
  • F12 - OSD Main Menu.

  

  • Activate FDC controller at OSD MENU
  • Select an Image from games/Oric directory, exit OSD and press F11. System will boot inmeddiately

The Oric Fpga preservation TEAM

• Ron Rodritty: Team coordination and QA testing.

• Fernando Mosquera: FPGA guru.

• Subcritical: Verilog and VHDL.

• ManuFerHi: Hardware consulting.

• Chema Enguita: Oric Software gurú

• SiliceBit: Oric hardware Gurú

• ZXMarce: Hardware support 24/7...

• Ramón Martínez: Oric hardware, Some software, and fpga coding.

• Slingshot: SDRAM work and advisor.

• Kudos to: Sorgelig, Gehstock, DesUBIKado, RetroWiki and friends.

About disk images

Despite the .dsk extension, Disk images must use the defacto standard edsk for disk preservation (also known as "AMSTRAD CPC EXTENDED FORMAT"). To convert images from the Oric "dsk" to the needed "edsk" you need the HxCFloppyEmulator tool (source code here).

Load the Oric disk and export it as CPC DSK file The resulting image should load flawlessly on the Oric. Always use a .dsk extension for your output file These images are also compatible with fastfloppy firmware on gothek, cuamana reborn, etc. working with real Orics.

About tape images

Loading from a tap file is currently supported in this core, but you can also convert .tap files to dsk with the OricDSK Disc Manager Tool. Then convert the resulting "dsk" to the supported "edsk" (CPC format) with HxCFloppyEmulator as explained above.

Tape to dsk conversion is also possible with tap2dsk from the Euphoric Tools pack.

This core does also support real-world (physical) Tape loading (via audio cable on the RX pin).

Troubleshooting disks

• If dsk is bootable, simply select the image, exit the MiSTer OSD, then press F11.
• If dsk is NOT bootable, after inserting, try DIR to list contents then !NAME_OF_FILE_TO_RUN to load and run.
• If you see errors like Insert System Disk try loading the SEDORIC first, exiting to the BASIC prompt, insert your dsk and use DIR, !NAME_OF_FILE_TO_RUN.

NOTE: There are known loading issues with multipart dsks; e.g. programs that use CLOAD to load in additional data from the dsk.

Software redistribution.

In the dsk directory, you will find some disk images in the proper format.

• SEDORIC 4.0 operating System disk image redistributed with permission from Symoon.
• Blake's 7 game, redistributed with permission of chema enguita you can download manual and additional info from Defence force
• Oricium game, redistributed with permission of chema enguita you can download manual and additional info from Defence force
• Space:1999 game, redistributed with permission of chema enguita you can download manual and additional info from Defence force
• 1337 game, redistributed with permission of chema enguita you can download manual and additional info from Defence force