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Commodore 1541
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Commodore 1541
The Commodore 1541 (also known as the CBM 1541 and VIC-1541) is a floppy disk drive which was made by Commodore International for the Commodore 64 (C64), Commodore's most popular home computer. The best-known floppy disk drive for the C64, the 1541 is a single-sided 170-kilobyte drive for 5¼" disks. The 1541 directly followed the Commodore 1540 (meant for the VIC-20).
The disk drive uses group coded recording (GCR) and contains a MOS Technology 6502 microprocessor, doubling as a disk controller and on-board disk operating system processor. The number of sectors per track varies from 17 to 21 (an early implementation of zone bit recording with 4 constant angular velocity zones). The drive's built-in disk operating system is CBM DOS 2.6.
The 1541 was priced at under US$400 at its introduction. A C64 with a 1541 cost about $900, while an Apple II with no disk drive cost $1,295. The first 1541 drives produced in 1982 have a label on the front reading VIC-1541 and an off-white case to match the VIC-20. In 1983, the 1541 switched to the familiar beige case and a front label reading simply "1541" along with rainbow stripes to match the Commodore 64.
By 1983, a 1541 sold for $300 or less. After a home computer price war instigated by Commodore, the C64 and 1541 together cost under $500. The drive became very popular and difficult to find. The company said that the shortage occurred because 90% of C64 owners bought the 1541 compared to its 30% expectation, but the press discussed what Creative Computing described as "an absolutely alarming return rate" because of defects. The magazine reported in March 1984 that it received three defective drives in two weeks, and Compute!'s Gazette reported in December 1983 that four of the magazine's seven drives had failed; "COMPUTE! Publications sorely needs additional 1541s for in-house use, yet we can't find any to buy. After numerous phone calls over several days, we were able to locate only two units in the entire continental United States", reportedly because of Commodore's attempt to resolve a manufacturing issue that caused the high failures.
The early (1982 to 1983) 1541s have a spring-eject mechanism (Alps drive), and the disks often fail to release. This style of drive has the popular nickname "Toaster Drive", because it requires the use of a knife or other hard thin object to pry out the stuck media,[citation needed] just like a piece of toast stuck in an actual toaster. This was fixed later when Commodore changed the vendor of the drive mechanism (Mitsumi) and adopted the flip-lever Newtronics mechanism, greatly improving reliability. In addition, Commodore made the drive's controller board smaller and reduced its chip count compared to the early 1541s (which had a large PCB running the length of the case, with dozens of TTL chips). The beige-case Newtronics 1541 was produced from 1984 to 1986.
All but the very earliest non-II model 1541s can use either the Alps or Newtronics mechanism. Visually, the first models, of the VIC-1541 denomination, have an off-white color like the VIC-20 and VIC-1540. Then, to match the look of the C64, CBM changed the drive's color to brown-beige and the name to Commodore 1541.
The 1541's numerous shortcomings opened a market for a number of third-party clones of the disk drive. Examples include the Oceanic OC-118 a.k.a. Excelerator+, the MSD Super Disk single and dual drives, the Enhancer 2000, the Indus GT, Blue Chip Electronics's BCD/5.25, and CMD's FD-2000 and FD-4000. Nevertheless, the 1541 became the first disk drive to see widespread use in the home and Commodore sold millions of the units.
In 1986, Commodore released the 1541C, a revised version that offers quieter and slightly more reliable operation and a light beige case matching the color scheme of the Commodore 64C. It was replaced in 1988 by the 1541-II, which uses an external power supply to provide cooler operation and allows the drive to have a smaller desktop footprint (the power supply "brick" being placed elsewhere, typically on the floor). Later ROM revisions fixed assorted problems, including a software bug that causes the save-and-replace command to corrupt data.
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Commodore 1541 AI simulator
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Commodore 1541
The Commodore 1541 (also known as the CBM 1541 and VIC-1541) is a floppy disk drive which was made by Commodore International for the Commodore 64 (C64), Commodore's most popular home computer. The best-known floppy disk drive for the C64, the 1541 is a single-sided 170-kilobyte drive for 5¼" disks. The 1541 directly followed the Commodore 1540 (meant for the VIC-20).
The disk drive uses group coded recording (GCR) and contains a MOS Technology 6502 microprocessor, doubling as a disk controller and on-board disk operating system processor. The number of sectors per track varies from 17 to 21 (an early implementation of zone bit recording with 4 constant angular velocity zones). The drive's built-in disk operating system is CBM DOS 2.6.
The 1541 was priced at under US$400 at its introduction. A C64 with a 1541 cost about $900, while an Apple II with no disk drive cost $1,295. The first 1541 drives produced in 1982 have a label on the front reading VIC-1541 and an off-white case to match the VIC-20. In 1983, the 1541 switched to the familiar beige case and a front label reading simply "1541" along with rainbow stripes to match the Commodore 64.
By 1983, a 1541 sold for $300 or less. After a home computer price war instigated by Commodore, the C64 and 1541 together cost under $500. The drive became very popular and difficult to find. The company said that the shortage occurred because 90% of C64 owners bought the 1541 compared to its 30% expectation, but the press discussed what Creative Computing described as "an absolutely alarming return rate" because of defects. The magazine reported in March 1984 that it received three defective drives in two weeks, and Compute!'s Gazette reported in December 1983 that four of the magazine's seven drives had failed; "COMPUTE! Publications sorely needs additional 1541s for in-house use, yet we can't find any to buy. After numerous phone calls over several days, we were able to locate only two units in the entire continental United States", reportedly because of Commodore's attempt to resolve a manufacturing issue that caused the high failures.
The early (1982 to 1983) 1541s have a spring-eject mechanism (Alps drive), and the disks often fail to release. This style of drive has the popular nickname "Toaster Drive", because it requires the use of a knife or other hard thin object to pry out the stuck media,[citation needed] just like a piece of toast stuck in an actual toaster. This was fixed later when Commodore changed the vendor of the drive mechanism (Mitsumi) and adopted the flip-lever Newtronics mechanism, greatly improving reliability. In addition, Commodore made the drive's controller board smaller and reduced its chip count compared to the early 1541s (which had a large PCB running the length of the case, with dozens of TTL chips). The beige-case Newtronics 1541 was produced from 1984 to 1986.
All but the very earliest non-II model 1541s can use either the Alps or Newtronics mechanism. Visually, the first models, of the VIC-1541 denomination, have an off-white color like the VIC-20 and VIC-1540. Then, to match the look of the C64, CBM changed the drive's color to brown-beige and the name to Commodore 1541.
The 1541's numerous shortcomings opened a market for a number of third-party clones of the disk drive. Examples include the Oceanic OC-118 a.k.a. Excelerator+, the MSD Super Disk single and dual drives, the Enhancer 2000, the Indus GT, Blue Chip Electronics's BCD/5.25, and CMD's FD-2000 and FD-4000. Nevertheless, the 1541 became the first disk drive to see widespread use in the home and Commodore sold millions of the units.
In 1986, Commodore released the 1541C, a revised version that offers quieter and slightly more reliable operation and a light beige case matching the color scheme of the Commodore 64C. It was replaced in 1988 by the 1541-II, which uses an external power supply to provide cooler operation and allows the drive to have a smaller desktop footprint (the power supply "brick" being placed elsewhere, typically on the floor). Later ROM revisions fixed assorted problems, including a software bug that causes the save-and-replace command to corrupt data.
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