Altair 8800 connect to the internet ¿?

General discussions related to the Altair 8800 Clone

Re: Altair 8800 connect to the internet ¿?

Postby kwiebe » April 16th, 2019, 8:54 pm

Does the foregoing discussion mean that you couldn't connect a modem to the clone serial port and use it to connect somewhere over analog phone line?

There is a video of an IMSAI doing this. I think he's using CP/M Xmodem to control the modem (no AT command necessary I don't think). Link below.

So, we obviously have CP/M for the clone. I can't tell from this thread whether attaching a modem serially and running Xmodem would succeed as it does with the IMSAI.

https://www.youtube.com/watch?v=nq4g6SLC8NM
-Ken
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Re: Altair 8800 connect to the internet ¿?

Postby TomXP411 » April 17th, 2019, 11:17 am

There's no obvious reason it shouldn't. The only question is which serial port XMODEM is designed to run with. Other communication programs I've found seem to have plugins for different hardware, so you'd just need to set up the system for the 2SIO cards used in the Altair.

no AT command necessary I don't think


Yes, it's necessary... you just don't see it because XMODEM hid that part of the communication. All smart modems have some sort of command interpreter, and even dumb modems still need a way to dial a phone number - my old Commodore modem, for example, used the programmable lines on the User port to trigger different oscillators to send DTMF tones, and the "pulse dialing" mode was even more primitive - the system literally just toggled the "off hook" line repeatedly to dial.

But in the case of terminal servers (that's what a "wifi modem" really is), you must send a string to the terminal server's controller to tell it to connect to a remote host. While most of these devices have adopted the AT standard, some people making homebrew devices may be using something like NodeMCU or MicroPython, which expect Lua or Python scripts.

(In fact, I'm building a terminal server using NodeMCU, just to be different. I haven't done anything with it lately... I really should get back to it and finish that project.)
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Re: Altair 8800 connect to the internet ¿?

Postby kwiebe » April 17th, 2019, 5:28 pm

TomXP411 wrote:But in the case of terminal servers (that's what a "wifi modem" really is)


Thanks. And just so I'm clear, the discussion in this thread with respect to WiModem and connecting to BBS's pertains to IP-accessible BBS's, right?

The choice of device names and terms used to describe things, especially when adapting one protocol to another can hinder understanding. There's just no substitute for a diagram sometimes.
-Ken
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Re: Altair 8800 connect to the internet ¿?

Postby TronDD » April 17th, 2019, 7:24 pm

kwiebe wrote:Thanks. And just so I'm clear, the discussion in this thread with respect to WiModem and connecting to BBS's pertains to IP-accessible BBS's, right?


Yes.
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Re: Altair 8800 connect to the internet ¿?

Postby MajorClements » October 23rd, 2022, 11:57 pm

TomXP411 wrote:You can also use a WiModem to connect to the Internet. The WiModem is a microcontroller with an RS-232 interface, and it's very useful on systems like the Altair Clone. I've started using one, since it lets me connect to the Altair from across the room, and I can leave the system on my dresser, where it lives these days.

I use this unit by Jim Drew:
https://www.cbmstuff.com/proddetail.php ... dem232OLED

and a 3D printed case from COREi64
https://corei64.com/shop/index.php?rout ... uct_id=117

To make this work, you do need a couple of additional components. Since the Altair is wired as a DCE device (like a modem), it needs a male-male DB25 cable and a null modem adapter. It also needs 5v power. Rather than use an external power adapter, I got a small USB regulator. It was originally intended to hook up a Raspberry Pi, but it also works for the WiModem.

here's an example:
https://www.amazon.com/dp/B00CGQH1RQ/

You can also use the WiModem on the second serial port for dialing out to other systems... it acts just like a Hayes modem from back in the day; you can connect to other nodes with the ATD command, and you can answer an incoming call with ATA. This makes it nearly 100% compatible with legacy terminal software. The only software that doesn't work is software that tries to be too smart and filter text out of the dial string (Telemate did this; it converted letters to their telephone keypad numeric equivelant.)



Hi TomXP411.

I recently picked up a similar Serial to “WiFi Modem,” for my vintage ThinkPads, mainly for the 380ED. I was hoping to get it to work on the Altair too. Mine doesn't have the screen, and crashes when the Baud is set higher than 9600…

Website: https://www.tindie.com/products/theoldn ... puters-v4/

Is there a recommended terminal emulator program for CP/M 3.0 (preferably) or 2.2? I guess one might call it Terminal-ception. I was planning to implement an automatic date and time setter for a “Y2K-complient, banked-memory”-version of CP/M 3.0 (either when Mike creates one or I decide to build one, or someone else already did and I haven’t noticed yet). The connection is DB9, but I already sourced an adapter. I believe there’s now a mod that brings TCP/IP to the unit as well. I’m not quite sure how that specifically works, but it does it very well.
Sincerely,
Daniel
________________________________________________________________________________
“THINK!”
If you had to remember only one thing about me, just know that I’m the guy with too many ThinkPads to count.
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Re: Altair 8800 connect to the internet ¿?

Postby Wayne Parham » October 24th, 2022, 11:02 am

I think this may be slightly off-topic, but it might be useful. It's not how I connect my Altair to the internet but rather how I connect terminal devices to the Altair over IP. It allows me to connect a remote laptop via WiFi using Putty or TeraTerm.

There are several RS-232-to-Ethernet devices available, but some are pretty clunky. I tried a few from Amazon that had software drivers that either didn't work with Windows 10 or wouldn't allow IP settings that were compatible with my network.

However, I've had good luck with devices purchased at the link below. They allow me to connect Altair (88-2SIOJP) ports 0 and 1 to my local ethernet, both with their own fixed IP addresses, which I assigned during setup. I run 9600 baud for port 0, which is what I regularly use for console I/O. Port 1 is set to 38,400 baud and it works great for PC2FLOP and FLOP2PC transfers.

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