computer (Or Commodore 64DX, C65, C64DX) The last 8-bit computer designed by
Commodore Business Machines, about 1989-1991. The C65 boasts an
ugly collection of
custom integrated circuits which makes even the
Amiga hardware look standard.
The core of the C65
chipset is the CSG 4510 and CSG 4569. The 4510 is a 65CE02 with two
6526 CIAs. The 4569 is equivalent to a combination of the 6569 VIC-II and the
MMU of the
Commodore 64. The C65 also has a DMA controller (Commodore's purpose built DMAgic) which also functions as a simple
blitter, and a floppy controller for the internal
Commodore 1581-like disk drive. The floppy controller, known as the F011, supports seven drives (though the
DOS only supports 2). The
4510 supports all the
C64 video modes, plus an 80 column text mode, and bitplane modes. The bitplane modes can use up to eight bitplanes, and
resolutions of up to 1280 x 400. The
palette is 12-bit like the Amiga 500. It also has two SID's (MOS 8580/6581) for stereo audio.
The C65 has two busses, D and E, with 64
kilobytes of
RAM on each. The VIC-III can access the D-bus while the CPU accesses the E-bus, and then they can swap around. This effectively makes the whole 8MB
address space both chip ram and fast ram.
RAM expansion is accomplished through a
trap door slot in the bottom which uses a grock of a connector. The C65 has a C128-like native mode, where all of the new features are enabled, and the CPU runs at 3.5 megahertz with its
pipeline enabled. It also has a C64 incompatibility mode which offers approx 50-80% compatibility with C64 software by turning off all its
bells and whistles. The
bells and whistles can still be accessed from the C64 mode, which is dissimilar to the C128's inescapable C64 mode.
Production of the C65 was dropped only a few weeks before it moved from the Alpha stage, possibly due to Commodore's cash shortage. Commodore estimate that "between 50 and 10000" exist. There are at least three in Australia, about 30 in Germany and "some" in the USA and Canada.
(1996-04-07)