Real-name Kates-playground

How to describe HERITAGE / 1 (in short)?

A minicomputer twentieth century home built in the century XXI designed to do useful work in the fashion of those times.

BASASTE WHAT DOES THE ELECTION OF THE HISTORICAL CONTEXT?

dedición There was a sudden, it started developing naturally over the first two months.

wanted to build my machine with integrated circuits 7400 series, so you should place it after 1966, that they were invented. But in those days, computers used ferrite memory - impossible for me! - Hence the second dimension in 1972, the year that Intel made a massive release of its first semiconductor memory (1103).

In 1972, however, the "minis" were no longer as simple as pretending to be my Heritage / 1. Already using virtual memory, hard drives and microprocessors to support tasks (such as terminals). Therefore decided imagine a machine designed in 1966 with ferrite memory, which was replaced later with semiconductor memory once it was available (1972).

plays in my favor modular design of Heritage / 1. Indeed, the memory is located in a dedicated unit, separated from the CPU, linked to it by a proprietary bus that consists of two ribbon cable. So, in real life, there would have been difficult to replace the old ferrite semiconductor memory.

notice that I have been strict with this historical context (1966-1972) but only up to where it was reasonable to do so. For example, my memory is Intel 1103 (Dynamic 1Kx1) but 6264LP-70 (SRAM 8Kx8 70ns). Also, my chips are not equivalents HCMOS TTL but since the former consume too much energy and get very hot. Nor

tapes but I will use diskettes, but "thought" as tapes. And I will not teletype terminals only on PCs running MS-DOS Kermit.

can a machine "useful" or a machine, "IN USE"?

One assumption is that it is usable, which provides guidance for the design itself: it comes to producing a minicomputer, not an experiment, many dediciones design have been based on that premise.

My dream - besides that it really works! - Is used in workings of my day-to-day. I do not think I trust my personal computer system, but may charge you some odd jobs as a simple mathematical calculations and control tasks. The latter will be easier in a simple and well known hardware such as the Heritage / 1 on a PC where, between hardware and application software, there's a chasm.

OPERATING SYSTEM WILL USE WHAT HERITAGE / 1?

not know yet. Now I am focused entirely on the hardware design. A hardware optimized for a certain system OS? No, not really, and this is part of the "culture" of Heritage / 1.

The only interest of the hardware, in general, is to support an increasingly demanding software. The real action is in the software, this is a reality that has existed for decades. Heritage / 1, however, lies in a historical context where the hardware was still cause for concern to the programmers themselves.

So this project is, say, the opportunity to savor the view of a computer design and electronic devices (hardware only) ... the software will come later. And fortunate, then surprised that something so intricate as an operating system can run on that monster that was not designed expressly for him.

But, Heritage / 1 run any operating system in the end. My dream (long term) is to carry a Minix or Unix clone as netBSD, but I can not guarantee because dreams are dreams ...

DREAM Anything else?

I believe every hobby project serves as inspiration and practical knowledge channeling Heritage / 1 is not an exception. After all knowledge (in general) is an abstraction and as such, a dream.

The Heritage / 1, in particular, has get to be exposed to a wealth of knowledge that only news was very vague. The mere desire to run Unix Heritage / 1, for example, has led me to explore that culture (Unix is \u200b\u200ba culture rather than an operating system) to point to install NetBSD on an old PC and get to play with him.

Another dream is that this experience serves not only to me. I'm not focused on it, but I would like the documentation of this project would serve the dessert for the benefit of hobbyists and students, in the same way that I have served on other (prior to me) as Bill Buzbee's Magic-1 and John Doran's D16 / M (see links).

Diaper Punishment Clips

Auto-interview System Files "in V-TAPES? Technical Manuals

I said that Heritage / 1 does not use fixed disks (hard drives), at least occurring during childhood. The type of storage to which I mentally focused is the V-TAPE ", ie simulating a floppy disk comportamento a magnetic tape of the old days.

I've seen recently that I have not actually writing a file system for it not just format my floppy disks for use in low level "raw floppies," a concept used in real life today.

But the point that concerns me is another: How do you manage the OS to handle configuration files housed in the media so slow? Incidentally, I'm tempted to use an "open reel audio and storage as well.

The case is a typical Unix-like operating system is based on many files configuration, as well as shell-scripts to run. Would not it be then too costly-in terms of time-constant reading of files to tape or V-TAPE? On the other hand did few films and V-TAPES I will have to provide only for the exclusive use of the OS?

I think the answer is to keep these files loaded into memory all the time, or at least as long as there is memory available for applications. This usually leads me to a caching mechanism that involves not only the system files but everyone in general. CACHE

It's always interesting at the same time intricate. The system must retain the image of the files and decide priorities remove them when memory for other more urgent file being loaded (eg a program). And those priorities should be indicated somewhere ... such a configuration file!

Another way (parallel) to increase the efficiency of access to storage. For example, provide some means for my "open reel" can quickly find files on the tape that is mounted. It occurs to me, for example, that the machine count the rotations of the motor 'take' and on that basis provide "general direction" of the files stored on the tape. The machine speed rebobinaría of seaweed, but counting rounds, so that when considered to be close to the target, pursue Search for speed.

For this, the driver of the machine must have an internal memory (not memory map) to save a kind of directory, which was read from the tape itself at "mount-time."

The same problem (and perhaps more so) comes with my Run-Time Library (RTL), which should be available for different programs, but also occupies a significant place in memory.

interesting thing about all this is to explore how such work that our modern operating systems solved "easily" through the possession of an enormous disc, can be solved in an environment where estorage is low, slow and low capacity ... How they did in the 60s ... precisely that question.

Silver Nitrate And Cancer Cervix

According to Dennis Ritchie himself , UNIX Manual was born as a documentation project very seriously. This extra effort was taken in its elegance often documenting code was corrected so that "shone well" in the pages of the Manual.

Since then, all UNIX system (or clone) is equipped with an electronic help system called "Man Pages", the structure that respects the original 1972 manual. And not only the structure but also much of its content, such as the command forgotten DC (Desktop Calculator).

The fact that a double serve Manual to document what has been done and guide what is done, it seemed an idea worth is taken and that is how I added to official site of Heritage / 1 a series of "books" called respectively: "Operator's Manual" "Engineer's Handbook" and "Programmer's Manual."

These days I have devoted much time to structure and generate content for Engineer's Manual. I'm sure someone will read it, but as serious documentation of the project and as a reference for myself, there is very good, as I watch.