User:Kitchen2010/sandbox

Previous

Previous emulator running the NeXTSTEP ROM Monitor on the Ubuntu Linux host
Original author(s)	Gilles Fétis
Developer(s)	Previous team: Gilles Fétis, et al.
Stable release	0.3 / January 25, 2012 (2012-01-25)
Written in	C
Operating system	Cross-platform
Type	Emulator
License	GNU GPL version 2
Website	previous.alternative-system.com

Previous is an open source emulator of the proprietary 68k-based NeXT computer system family, aiming at emulating the original 68030-based NeXT Computer and the 68040-based NeXTstation and NeXTcube computers with all its peripheral.

The emulator was created with the goal to make the early versions of the NeXTSTEP operation systems (0.8, 1.x, 2.x and 3.0) and original NeXT software (e.g. Lotus Improv and Altsys Virtuoso), that was never ported to the x86, available to the today's users.

The emulator is based on the sourcecode of the Hatari emulator with additional CPU code from the WinUAE emulator. Previous is currently developed on Linux and Mac OS X and has been reported to successfully compile on the Windows platform.

As of June 2012 (version 0.3), the emulator is still incomplete. Currently it passes the power-on tests and boots sucessfully to the NeXTSTEP ROM Monitor.

Emulated hardware

Previous emulates the following computer peripherals (as of version 0.3):

• Processor:
  • Motorola 68030 CPU with MMU and Motorola 68882 FPU unit (broken)
  • Motorola 68040 CPU with FPU and MMU unit (almost complete)
• Memory:
  • System memory (RAM) up to 32 MB for NeXTstation models and up to 64 MB for NeXTcube models
  • Video memory (VRAM) for 2-bit greyscale graphics
  • System read-only memory (ROM) accepted for the 68030-based (1.x) and 68040-based non-Turbo models (2.x)
• Devices:
  • NCR53C90 SCSI host controller
  • Keyboard
• Timers:
  • Real-Time Clock
  • 2 Internal Timers
• DMA for the SCSI host controller

Future Plans

Currently, the main goal is to complete the hardware emulation, so that the NeXTSTEP operation system can be completely booted. Following areas need more work:

• Processor:
  • completation of Motorola 68040 FPU Unit
  • completation of Motorola 68030 FPU and MMU Unit
• Memory:
  • Make emulation compatible to NeXTstation Turbo and NeXTcube Turbo models (3.x ROMs) to enable more system memory (RAM) capacity (up to 128 MB)
• Devices:
  • completation of SCSI emulation for hard disk and CD-ROM drives to enable installation of NEXTSTEP operation system
  • completation of keyboard emulation
  • Ethernet emulation
  • serial communication controller emulation
  • MO-Drive controller emulation
  • mouse emulation

On the long-term wish list is the emulation of:

• Motorola 56001 DSP for Sound and Modem capabilities
• NeXTbus (NeXT-specific implementation of the NuBus)
• Graphics hardware of the NeXTstation Color models (4,096 colors (12-bit) with 4-bit alpha channel)
• Intel i860 CPU for the NeXTdimension 32-Bit color graphic card
• 2.88 Mb floppy drive
• NeXT Laser Printer for Printing ability

External links

• Official Previous Homepage
• Sourcecode Repository at Sourceforge
• Developer's Discussion Thread on Previous
• Discussion Thread on the QEMU-NeXT branch

Category:Cross-platform free software Category:Emulation_software_stubs Category:Linux emulation software Category:Windows emulation software Category:Mac OS X emulation software Category:Free emulation software