# reading matter | Every byte is valuable. Intel MCS-85

Recently, we talked about quite respectable computers. But today we will speak about a computer from a well-known Intel corporation, the one that provides modern Macs for its processors. The Intel MCS-85 was minimalist even at the time. Suffice it to say that its RAM (RAM, RAM) was only 256 bytes, that is, a quarter of a kilobyte.

The Intel 8085A processor ran at 3 megahertz. Pretty good for the late 1970s. About why the memory was so small with a sufficiently powerful processor, we will discuss later. Intel MCS-85 possessed a LED (LED) screen. Its only port was a 38-line parallel bus. And the operating system was the well-known “Monitor” platform, which was comfortably located in its permanent memory (ROM, ROM).

It was a test computer. In past years, Intel, having announced once again a new processor, created a computer system. It was a sampler, a computer that had only one task: to demonstrate to engineers, students, and other (few in those early years) potential consumers of computer technology the capabilities of the new Intel microprocessor. No information could be found on the price of this outlandish computer device. One can only assume that it was relatively inexpensive.

If you prefer the accuracy of the beauty of the syllable, then we have a kit for the assembly, rather than a ready-made computer: Intel MCS-85 System Design Kit (SDK). That is, a system designer named Intel MCS-85. The designer contained all the components necessary for the end user to be able (with knowledge and skills in the field of electronics) to assemble a computer. For the seventies of the last century, this was quite a traditional approach from computer companies. Such designers were cheaper than ready-made microcomputers. Yes, and personal computers were in those years not only and not so much functional devices, as toys for radio amateurs.

So, the Intel MCS-85 designer kit included a six-digit liquid crystal display, as well as a 24-button keyboard for direct input of programs, their testing and execution. It's an amazing thing, but Intel MCS-85, when connected to a teletype terminal, could act as a communication device.

Intel MCS-85 permanent memory was pre-programmed and included a system monitor for software utilities and system diagnostics. The system could be expanded with additional circuits.

Adapted from oldcomputers.net

The article is based on materials https://hi-news.ru/computers/chtivo-cenen-kazhdyj-bajt-intel-mcs-85.html.