Datasette
The budget method for data storage on the Commodore was the Datasette, which used widely-available compact audio cassette tapes as its storage medium. By keeping track of the revolution counter, users could return to and reload stored programs. With help from various types of turbo software accelerators, this cassette drive was about as fast as a diskette drive, and could store more data. But the device also required constant azimuth adjustments to the read/write tape heads, using a jeweler's screwdriver and an azimuth adjustment program to get settings just right. Today's users would never accept such a need for constant calibration and adjustment!
The Final Cartridge III
The best-sellling Commodore C64 cartridge of all time was called The Final Cartridge III, produced by Riska B.V. Home and Personal Computers. It included reset and freeze buttons that could permit program execution to be reset, frozen and restarted on demand. It also include a fast loader that increased the speed of the disk drive, and a way to disable all extended features for use with programs that required an unaltered, plain vanilla C64 runtime environment. At its debut, this cartridge cost about $50 (100 DM).
The Last Days Of GEOS
The final days of the Commodore C64 began with the release of GEOS version 2.5 in 1993.
64'er Magazine
In Germany, the most active outlet for the C64 community was 64'er Magazine, which served for many years as a primary source for market and technical information. In the US and Canada, numerous publications served this community as well, including some names now long forgotten, such as Compute!, Gazette Magazine, Run, Ahoy, Commodore Power Play, ZZap!64, Commodore World, and Die Hard. The Canadian Commodore society has a nice gallery of related publications on its Commodore Computer Magazine Articles archive page. Some used magazine dealers even specialize in reselling used Commodore publications from this era.
Code Listing Via Sheer Effort
This was also an era when lots of important software had to be typed in (or switched in) by hand, using the "Checksummer" utility to key individual code groups one at a time. This work often took an unbelievable number of hours to complete. By today's always-on Internet standards this level of labor (and love) is nearly unimaginable.
Centronics Printer Interface
A W&T Centronics printer interface for the Commodore 64 and 128 cost nearly $50 (100 DM) back in the day.
Commodore C128D
A real heavyweight: the Commodore C128D (aka "Diesel"), with its built-in diskette drive and external keyboard, cost nearly $500 (1,000 DM) in 1987.
Commodore C128D
Despite its name, most users ran the Commodore 128 in its C64 emulation mode. The C128 also included a genuine CP/M operating system onboard as well.
Commodore C128D
Three CPUs in a single enclosure: 1985 witnessed the introduction of the C128, originally conceived as a successor to the C64. In contrast to the C64, the Commodore 128D worked in three different modes. Along with its native C128 mode, it supported a C64 emulation mode and a CP/M mode. In fact, the C128 also integrated a 4 MHz Z80 processor specifically for CP/M support.
Special Software For The Commodore C128
Software designed specifically for the Commodore C128 was rare and hard to find, which is why most users ran their C128's in C64 emulation mode.