The A1000, or Commodore Amiga 1000, was Commodore's initial Amiga multimedia home/personal computer, released in 1985. Before follow-up models A500 and A2000 were released in 1987, the A1000 was just called the (Commodore) Amiga.
Technical specifications:
Motorola 68000 (32-bit CISC microprocessor with 16 registers lacking MMU for memory protection and virtual memory).
Default operating system AmigaOS 1.0 or 1.1 (having 32-bit pre-emptive multitasking microkernel) depending on the revision; loaded from the Kickstart floppy disk at power-on
256 KB of Chip RAM by default (sound buffers, graphics buffers and software existed in same memory space)
upper limit of 16 MB of memory due to MC68000 limitations (24-bit external address bus)
OCS chipset
50 Hz PAL and 60 Hz NTSC TV output by default versions available
50/60Hz mode switchable by software, although switching a PAL Amiga to NTSC mode produces a 60Hz PAL display, and vice versa (this would usually suffice for software relying on a particular format)
hardware-switchable low-pass audio filter (cut/join a track, many people built switches); software-switchable on later models
IRQ sharing (like the PCI bus)
IRQ system had 7 priority levels of interrupts
No limit on number of interrupts available
Resources handled by Autoconfig, very similar to ACPI, resources were not numbered or labelled, just given as amounts and addresses
No specific I/O ports, instead using memory-mapped I/O space separately for each hardware device
