Online Computer Terms Dictionary - C

Commodore 1010

<storage> A 3.5-inch floppy disk drive for the Amiga.

(1998-12-23)

Commodore 128

<computer> (C128) An expanded Commodore 64. The C128 was Commodore Business Machines' last commercially released 8-bit computer. However, they did prototype the Commodore 65 and Commodore SX64.

(1996-06-05)

Commodore 1541

<storage> The best know floppy disk drive for the Commodore 64. The 1541 was a single sided 160 Kb drive but converting to flippy disks would give another 160 Kb.

The disk drive used Group Code Recording and contained a 6502 processor as a disk controller. Some people wrote code for it to vibrate the head at different frequencies to play tunes.

The transfer rate was about 300 bytes per second. The 1541 used a bit-serial version of the IEEE 488 parallel protocol. Some third-party speed-ups could transfer about 4 kilobytes per second over the interface, and some "fast loaders" managed up to 10 kbps.

The Commodore 1570 was an upgraded 1541 for use with the Commodore 128.

(2000-03-07)

Commodore 1570

<storage> Commodore Business Machines's allegedly "advanced" disk drive for use with the C128. It is basically a 1541 with the capability to use "burst loading" (like the Commodore 1571), and lots of new bugs.

The Commodore 1571 was a double-sided version of the 1570.

(1996-04-07)

Commodore 1571

<storage> Commodore Business Machines's "advanced" disk drive for the C128. It was the double-sided version of the Commodore 1570 disk drive but, unlike the 1570, worked quite well.

The 1571 supported "burst mode" loading when used on a C128 in native mode, which increased the transfer speed from 1541 speed to about three kilobytes per second (about a 10-fold increase). The 1571 could be told to emulate a 1541 for use with a C64 or 1541 disks.

Bugs in early releases of the 1571 ROM affected access to the second side of the disk.

(1996-04-07)

Commodore 1581

<storage> Commodore Business Machines's 3.5 inch disk drive for the Commodore 64 and Commodore 128. The drive stores 800 kilobytes using an MFM format which is different from both messy-dos 720 kb, and the Amiga 880 kb formats.

The 1581 supports a poor imitation of directories which are really just partitions and largely unused. It also supports burst loading like the Commodore 1571, but is actually faster as it is better designed. It has 3160 blocks free when formatted.

The 1581 is the highest density C64 serial bus drive made by Commodore. However Creative Micro Designs (CMD) make the FD2000 (1.6MB) and (until recently) the FD4000 (3.2MB) 3.5" disk drives. GEOS users like 1581s as they are very fast when used with GEOS.

See also Commodore 1541, Commodore 1571.

(1998-12-23)

Commodore 64

<computer> (C64) An 8-bit Commodore Business Machines personal computer released around September 1981. Prototypes were (apparently) made before Christmas 1980 (and shown at some computer fair).

The CPU was a 6510 from MOS Technologies (who were a wholly owned subsiduary of Commodore at this time(?)). The C64 had 64 kilobytes of RAM as standard and a 40-column text, 320x200 pixel display generating composite video, usually connected to a television.

DMA-based memory expanders for the C64 (and C128) allowed 128, 256, and 512 kb of RAM. Several third party manufacturers produce accelerators and RAM expanders for the C64 and C128. (Some, risking a holy war, compare this to putting a brick on roller-skates). Such accelerators come in speeds up to 20MHz (20 times the original) and RAM expanders to 16MB.

The C64's 1541 5.25 floppy disk drive had a 6502 processor as a disk controller.

See also Commodore 65.

["Assembly language programming with the Commodore 64", Marvin L. De Jong].

(1996-06-05)

Commodore 64DX

Commodore 65

Commodore 65

<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)

Commodore Business Machines

<company> (CBM) Makers of the PET, Commodore 64, Commodore 16, Commodore 128, and Amiga personal computers. Their logo is a chicken head.

On 29 April 1994, Commodore International announced that it had been unable to renegotiate terms of outstanding loans and was closing down the business. Commodore US was expected to go into liquidation. Commodore US, France, Spain, and Belgium were liquidated for various reasons. The names Commodore and Amiga were maintained after the liquidation.

On 1995-04-21 CBM was bought by Escom AG, a German company and production of the Amiga resumed. Production of the 8-bit range alledgedly never stopped during the time in liquidation because a Chinese company were producing the C64 in large numbers for the local market there.

(1996-07-22)

Commodore SX64

<computer> A "portable" Commodore 64. Shaped vaguely like a seat cushion, this cumbersome experiment in transportable computers had a detachable keyboard on one end which, when removed, revealed a 6" monitor and a 5 1/4" floppy disk drive. The curious combination of a bulky design and microscopic display are the most likely cause for the SX64's discontinuation.

[Processor? RAM? Dates?]

(1997-10-25)