Re: How many SIG/M disks where there?

Mr. Emmanuel Roche, France schrieb:
Hello, Udo!

Ok. I am going to bed, and tomorrow, I will be away the whole day.

So, this will be short.

For any protocol you need a physical layer and defined frames to
transport that protocol. E.g. for TCP/IP ethernet is pretty common. If
you read the ethernet specs you'll find that frames for TCP/IP, Decnet
and Novell IPX are defined, CP/NET is not. And so you can run TCP/IP,
Decnet and Novell on the same wire, but not CP/NET. And I'm looking
forward how you talk layer 1 vendors into implementing CP/NET for you.

If I have well understood today's readings, most Web browsers work at the
4th level, where "levels" are:

4th: Application
3th: TCP
2nd: IP
1st: Ethernet

This is not the OSI layer model, but nevermind, this model will do too.
Let's call layer 1st transport layer, TCP/IP doesn't work on ethernet only, best example is your nowadays DSL connection to the Internet.

CP/NET was the first NOS for CP/M systems, and used the simplest possible
protocol at the time (1982), down to a checksum similar to Intel HEX files.

The DRI guys were smart. The checksum is optional, only needed with a transport layer, that doesn't do checksum and retransmission already.

But I don't see why you could not change it to use a TCP/IP driver using an
Ethernet card, such as those found on IBM PCs? (I found one article that

That is what I have done. It is called tunneling protocol xxx over TCP/IP. Another term used is encapsulating protocol xxx in TCP/IP.

claimed that TCP/IP could fit into 10 to 24KB. I have already disassembled a
dozen programs bigger than this size.)

Such claims are pretty useless. There is no need to disassemble, the TCP/IP stacks for Z80 systems are available as source code.

(I have spent a good deal of time, today, investigating TCP/IP,
searching
how it could be implemented under CP/M.)
Oh, it is already implemented, was done.

??? Under CP/M? Where? When? The name? (Not found with Google.)

Yours Sincerely,
Mr. Emmanuel Roche, France

Before I get into that 21th century google mystery, not running on CP/M or Windows, I'll tell you a top secret. The company Zilog, the guys who invented the Z80 processor, still produce a Z80 CPU right now. The thing is called eZ80. This little thingy is a Z80 CPU (with some extensions) and a complete TCP/IP protocol stack put into the hardware. There is much need for such a controller, so that you can get your coffee machine and your fridge connected to your LAN at home. Now that wouldn't help you much, you don't want to read your email from the display of a fridge, you want CP/M right? Well, look here: http://www.ez80sbc.com/
A complete system with that eZ80 already running CP/M 3. From the pictures it looks like ethernet is available via the usual CAT5 connector. All that is left to read email with this system is writing a BSD compatible socket library to interface with the TCP/IP protocol stack already available in the hardware, and then compiling the BSD mail and news programs (no licence restrictions, use other if you like) with a C compiler. 2-3 evenings of work maybe?

Google... when I enter "Z80 TCP/IP" as search string I get hundreds of hits, good matches on the first page already, describing ancient CP/M systems enhanced with a TCP/IP stack to run web servers, ftp clients, mail clients and all that stuff, ready to download and use, with all sources. The search string is pretty easy, you tried that of course, but obviously you didn't get the same result as I got. The top secret (if you tell that anyone I've to shot you, or so) is the national language configured in your web browser. I use different preferences than you, so I get different results, because google uses the language preference you configured in your web browser to compute the rank. OK, now all that learned, my language preference is de, en_us, en. I will not post the links I found, because obviously you need to learn to google and it won't help if I do it for you.

Udo Munk
--
The real fun is building it and then using it...
.

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