hile those TV-monitors had difficulty displaying the clear and readable 80-column text that became the industry standard at the time, the only consumers who really needed that were the power users utilizing the machine for business purposes, while the average casual consumer would use the system for games only and was content with the lower resolution for which a TV worked fine. An important exception was the Radio Shack TRS-80, the first mass-marketed computer for home use, which included its own 64-column display monitor and full-travel keyboard as standard features.
This "peripherals sold separately" approach is another defining characteristic of the home computer era. A first time computer buyer who brought a base C-64 system home and hooked it up to their TV would find they needed to buy a disk drive (the Commodore 1541 was the only fully compatible model) or Datasette before they could make use of it as anything but a game machine or TV Typewriter.
In the early part of the 1980s, the dominant microprocessors used in home computers were the 8-bit MOS Technology 6502 (Apple, Commodore, Atari, BBC Micro) and Zilog Z80 (TRS-80, ZX81, ZX Spectrum, Commodore 128, Amstrad CPC). One exception was the TI-99 series, announced in 1979 with a 16-bit TMS9900 CPU.The TI was originally to use the 8-bit 9985 processor designed especially for it, but this project was cancelled. However, the glue logic needed to retrofit the 16-bit CPU to an 8-bit 9985 system negated the advantages of the more powerful CPU. Another exception was the Soviet Elektronika BK series of 1984, which used the fully 16-bit and powerful for the time 1801 series CPU, offering a full PDP-11 compatibility and a fully functional Q-Bus slot, though at the cost of very anemic RAM and graphics. The Motorola 6809 was used by the Radio Shack TRS-80 Color Computer, the Fujitsu FM-7, and Dragon 32/64.
Processor clock rates were typically 1–2 MHz for 6502 and 6809 based CPU's and 2–4 MHz for Z80 based systems (yielding roughly equal performance), but this aspect was not emphasized by users or manufacturers, as the systems' limited RAM capacity, graphics abilities and storage options had a more perceivable effect on performance than CPU speed. For low-price computers the cost of RAM memory chips contributed greatly to the final product price to the consumer, and fast CPUs demanded expensive, fast memory. So designers kept clock rates only adequate; in some cases like the Atari and Commodore 8-bit machines, coprocessors were added to speed processing of graphics and audio data. For these computers clock rate was considered a technical detail of interest only to users needing accurate timing for their own programs. To economize on component cost, often the same crystal used to produce color television compatible signals was also divided down and used for the processor clock. This meant processors rarely operated at their full rated speed, and had the side-effect that European and North American versions of the same home computer operated at slightly different speeds and different video resolution due to different television standards.
Initially, many home computers used the then-ubiquitous compact audio cassette as a storage mechanism. A rough analogy to how this worked would be to place a recorder on the phone line as a file was uploaded by modem to "save" it, and playing the recording back through the modem to "load".Most cassette implementations were notoriously slow and unreliable, but 8" drives were too bulky for home use, and early 5.25" form factor drives were priced for business use, out of reach of most home buyers. An innovative alternative was the Exatron Stringy Floppy, a continuous loop tape drive which was much faster than a datacassette drive and could perform much like a floppy disk drive. It was available for the TRS-80 and some others. A closely related technology was the ZX Microdrive developed by Sinclair Research in the UK for their ZX Spectrum and QL home computers.
Eventually mass production of 5.25" drives resulted in lower prices, and after about 19