8-bit OS sought

looks the best

Pozdrawiam.

-- RusH //

Without at least 1 MByte of memory space it will be hard to cram an OS in. A tiny LCD display, say 8x40, a key board, a serial is doable, but also having a commandline interpreter doing something except interprete, eg copy, start a preinstalled app ... have a file system ...

Rene

This is blah. Do you know how *much* one MB is?

Go back in time, there are many many examples of completely functional operating systems that fit in a fraction of a megabyte.

S.

Absolutely. My first job was on a PDP-11 with 96Kb, running version 7 Unix with four concurrent users (including a real-time device using a driver I write). I could sit in the other room compiling C programs on one 2.5Mbyte hard disk while the other users got busy on the other and didn't even notice.

We've just built some web services using C# and DotNET, and a simple ping-type RPC on a 3.2GHz Pentium 4 with 2Gb of RAM takes 33 seconds to call 100 times. That's about a *billion instructions* just for a remote procedure call guys.... Get real! People have forgotten how to program.

... snip ...

We did all that in well under 64k of memory 25 years ago. It was called CP/M. One clone of that, with full source, is available at:

Try XMK

The first OS I'm aware of was on a 8086 with an adress space of 1MB, well, only 640k was useable if plugged in. Drivers, interpreter, communication, perhaps a compiler, all in 128k with 8k RAM is a bit tight.

Rene

Rene, you aren't listening. We aren't talking about the first OS you are aware of. We are telling you that you are unaware of the many, many OSs that run great on 8-bit 64K systems.

I worked for many years with Varian/Sperry Univac Vortex, a real-time, multi-tasking OS which used less than 24K.

The first Macintosh OS ran from 64K of ROM and used 128K of RAM for applications. No TCIP or NIC, but it did have a keyboard, display, and disk storage.

Mark Borgerson

CP/M itself didn't require anywhere near that much. I was the envy of my friends when I got a Kaypro which had a full 64K. We really didn't know what to do with so much memory.

The Commodore 128 does amazing things with 128K of RAM, a

All of the early computer manufacturers wrote operating systems that ran in less than 1 meg.

Megabyte is a foreign word to many (most?) embedded applications.

snipped-for-privacy@mojaveg.iwvisp.com (Everett M. Greene) wrote in news: snipped-for-privacy@mojaveg.iwvisp.com:

Commodore 64's and Apple ]['s ran Geos, a full mouse driven GUI system, on

Yes, but how many of them got a GUI into 128K RAM and

Mark Borgerson

I don't remember the details, but I've seen a PDP 15 doing some amazing stuff with a vector display and a spark pen with a lot less memory. But it probably was an ap, not the os that was doing it.

Have you shopped for a cellphone lately? :)

If you mean a GUI when introduced, that's an unfair question. Most of the 8-bit systems were introduced prior to VisiOn (1982) MacOS Lisa version (1983), MacOS (1984), GEM (1984) or Windows 1.0 (1985) - the first commercial GUIs.

In the years since then, just about every popular 8-bit

You might be interested in reading this:

That's what I developed DOSPLUS/CCPLUS on. I also replaced the EPROM, which originally had anomalous connections to the bios - something to do with the DEFDMA location, IIRC. That gave me the opportunity to correct some things, such as column 80 wraparound, and provide the ability to return serial and parallel port status, etc. that enabled routine remote operation.

That machine actually had over 64k available. Another 2k lived in the video memory, and still another 2k in the EPROM. The video decoding left 80 or so bytes available in the video memory, which I could use for some ROM specific things and know they were protected until banked in. That was the last machine I had 100% under my control. If anything annoyed me, I fixed it.

The end result was a system that could run BIG programs, the equivalent of 2 Meg of 8080 code (except actually more compact PCode - also my own) in a position independent segmented system that had intersegment calls and LRU automatic segment swapping. However the data memory was still limited, due to the lack of hardware support. And the biggest code item actually run was the compiler, which was about 65k of PCD and equivalent to about 200k of 8080 object.