While Heritage / 1 only exists on paper and half (although I'm building the first circuits), design counts as a personal experience which I have drawn some lessons.
CONTROL PANEL
could not imagine a minicomputer-70s without a control panel full of switches and lamps majable bit level. However, the design of this panel and, above all, your connection to the rest of the circuit have been presented so many difficulties that I even think of deleting it altogether.
In fact, my panel is much simpler than other "home-brew" minis that have been studied (See links), but even so it is recharged when compared with real minicomputers of the 70s as the DEC PDP-11. The difficulty of the panel is presented on two fronts: (1) requires a large number of connections to the CPU, and (2) can not be "smart" because it is the first place to look for failures to be so absolutely reliable.
the problems have been solved little by little at the expense of increasingly simpler. Finally I was able to reach a final design with which I am satisfied, not so with the large amount of time I had to spend.
As is teaching me a control panel should be as small and simple as possible with just essential for operating the machine, maybe not so much to help the development of programs. I did not want my current design to further simplify it, definitely, I have the experience to operate with all its switches and lamps. I learn from the practice of their resources which are useful and which not.
A general purpose machine
I set out to design a simple machine designed to address any type of work ... which is the same as saying no concrete work. In my article sixteen versus eight bits explored the idea of \u200b\u200ban optimized design as an alternative to general design that Heritage / 1 defintivamente took, for example, Heritage / 1 does not optimize the treatment of characters or flange support for a preemptive multitasking operating system with process protection.
The moral is that "general purpose" really means "large number of specific purposes." If I ever meet this challenge, I will apply this teaching to guide the design of certain "somethings", my effort will be led then to optimize for each of them.
HARDWARE ARCHITECTURE VS. SYSTEM SOFTWARE
One purpose of this project has been to provide an environment "understandable" where you can play at my leisure to design (or adoption) of system software. Although the architecture of computers has resulted apacionante for me, much more is being operating systems programming ... only that this can not penetrate until the hardware is not ready.
An alternative would be to design a feasible hardware to be assembled in a short time, for example using a microprocessor of the 80s generation as Intel 8085 or Zilog Z80, the cultural aspect had been satisfied with just "run the historical context" towards the decade. Only then I would have lost the "taste" of a machine with no mysteries, no "boot up" and without LSI, all that ultimately form part of the personality and culture Heritage / 1 .
DEFINITELY A "MAIN-FRAME"
The 80s brought the concept of "personal computer": a machine which justifies its use inexpensive dedicated to a single person. Today the computer has not only left the Computer Centre to the bureau, but this the pocket of the owner! "Indeed, a cell phone today is more powerful than a mainframe in the mid-60s as the IBM System/360.
current perceptions (both domestic and industrial) is that a computer must have a video card, a graphical interface and a mouse. Heritage / 1 vision carries the legendary anti definitely opposite: a computer only "computing" she be accessed through "terminal" outside, she, in itself, provides no way to be "look" or "commanded" directly by users.
A modern version of Heritage / 1 replace your serial ports (where the terminals are connected) through an Ethernet connection, and UNIX would show up as a "host" within a TCP / IP. The "terminal" would then desktops and Macs or PCs, or perhaps be manufactured proprietary terminals capable of presenting a graphical user interface, perhaps Web.
But always be, Heritage / 1 a centralized machine: a mainframe; not provide any means allowed to treat her like an ordinary desktop computer.
Thus it would seem rather to an IBM AS/400. My teaching in this regard is that the world of PCs do not find it attractive at all.
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