Floating point performance of the Am386 could be boosted with the addition of a 80387DX or 80387SX coprocessor, although performance would still not approach that of the on-chip FPU of the 486DX.
For example, 3D objects rendered in dots are somewhat tricky on systems without byte-per-pixel displays or limited video memory bandwidth, or systems with slow and/or limited (e.g. 8 bit, no FPU) CPUs.
Emulating such an architecture programmatically on a PC, characterised by the emphasis put on floating-point operations, and specialised graphics hardware with memory separate from the system memory would be extremely difficult, especially taking into account the scarcity of documentation typical for specialised, proprietary hardware.
There was a special version of the "Teal" Indigo², called Power Indigo²; this system had increased FPU (floating point unit) capabilities and used specially designed R8000 CPUs.
Later versions for 32 bit Amigas, an executable supporting the MC68881/68882 FPU is available, speeding up rendering considerably when such a chip is present.
FPU |
Sharing the same compact case design with three expansion slots, the IIci improved upon the IIcx's 16 MHz Motorola 68030 CPU and 68882 FPU, replacing them with 25 MHz versions of these chips.
The 40 MHz speed referred to the main logic board clock (the bus), the Motorola 68030 CPU, and the computer's Motorola 68882 FPU.
It replaced the 16 MHz Motorola 68020 CPU and 68881 FPU of the II with a 68030 CPU and 68882 FPU (running at the same clock speed); and the 800 KB floppy drive with the 1.44 MB SuperDrive (in fact, it was the first Mac to have one).
The Quadra 630 featured an 68040 processor, 4 MB of RAM, a 250 MB hard disk and a CD-ROM drive; the LC 630 was essentially identical, but had the FPU-less 68LC040 processor.
There are two versions of the Centris 650: One with 4 MiB of RAM soldered to the logic board and an FPU-less Motorola 68LC040 CPU, and one with 8 MiB of logic board RAM, a full Motorola 68040, and added an onboard AAUI port for Ethernet.
Like its predecessors, it was based on Motorola's 68040 microprocessor rather than the 68LC040 (which lacked an on-board FPU).