Arnold on Amiga

Date 18-May-2006 2:12:13
Topic: Software News

The Amstrad CPC emulator Arnold has been ported to AmigaOS 4. Click here for a screenshot of here to download it.


Arnold is very accurate and there is a small number of programs (mainly demos) that do not display correctly (especially those which use "horizontal splitting" technique). Arnold should run 99% of all programs and will run these as they would on a real CPC.

Arnold has been written to be portable and to be the most accurate Amstrad CPC and KC Compact emulation, and emulates many undocumented features.

+ Full 1us cycle emulation
+ undocumented features of the CPC+ asic
+ undocumented features of the various CRTC types
+ undocumented opcodes of the Z80
+ full support for Z80 interrupt mode 0, 1 and 2; interrupt mode 0 and mode 2 work as they would on the CPC+
(vectored interrupts supported, and the weird instruction execution of IM0)
+ all the features of the CPC+ hardware (including the incompatibilities between the CPC+ and the CPC)
+ all the features of the CPC hardware
+ Genius mouse
+ Digital joysticks
+ different ram expansions: DK'tronics 64k or Dk'Tronics 256K Silicon Disc
+ Multiface 2 (the final model with automatic switch)
+ Digiblaster 8-bit D/A sound device
+ Inicron RAMROM device
+ tape emulation using tape images or sampled/digitised sounds
+ disk emulation using disk images
+ CPC+ cartridge emulation using cartridge image files
+ scan-line interrupts from the Z8536 CIO for the KC Compact
+ undocumented operation of the AY-3-8912 I/O ports.

Not emulated:

- undocumented mode 3 in KC Compact mode
- analogue joysticks
- not all operations of the Z8536 in the KC Compact
- not all operations of the 8255 in the CPC are supported
- interrupt vector bug of CPC+ ASIC.
- keyboard "clash"
- undocumented flags are not perfect for all commands.
- cycle-level disc access; programs do not load at real speed.
- other Amstrad hardware...
- the sound emulation could do with more work
- the effects of the monitor hsync and vsync which produces bending patterns
with some programmed values
- monitor brightness control
- still many bugs with the CRTC emulations.

Other features:

+ ASL requesters.
+ Support for USB Joysitcks via Amiga Input.
+ Double size mode.


- uses all the cpu resources.
- slower in fullscreen mode than in window.
- renders graphics only on 32-bit depth.
- when emulating some noises - the emulator crashes - represented when playing "Space Harrier".
- double size mode is slow.
- when set frameskip, the emulator speeds up instead of working at 100% speed and skipping frames.

This article comes from AmigaWorld - Amiga Community Portal

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