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cyberferret

Things that I still find hard to forget these days:

* ASCII codes for those single and double box characters, so I could draw a fancy GUI on those old IBM text monitors

* Escape codes for HP Laserjets and Epson printers for bold, compressed character sizes etc.

* Batch file commands

* Essential commands for CONFIG.SYS

* Hayes modem control codes

* Wordstar dot format commands

* WordPerfect and DisplayWriter function keys

* dBaseII commands for creating, updating and manupulating records

I wish they would all move out of my head and leave room for me to learn some new stuff quicker!

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Fun fact: Your smartphone is still using (extended) Hayes commands to control the cellular modem inside.

LTE smartphones too?

You'd be surprised how little has changed in that regard. Establishing a data session, from the early GPRS days until today's LTE, is still:

    ATD*99***1#

Even if the underlying technology has completely changed, the interface has not.

Whoa! I just dialed that on my Nexus 5x and got

> USSD code running...

then

> Connection problem or invalid MMI code.

So what was my phone just trying to do?

Hook your phone to your computer via USB and try to invoke that command on the serial port that appears; you'll get a PPP connection right away. It won't work with the dialpad app.

You are not supposed to dial 99# from the phone UI. It's special number that gets interpreted by the phone hardware itself and switches it to essentially router/access-server mode (the 1 at the end is optional parameter which is index of configuration you want, with the configurations being defined by AT+CGDCONT), most common thing that happens is that phone estabilishes PPP session with whatever device that sent ATD*99# and then routes it through packed based celular networkg (ie. GPRS/EDGE/UMTS/LTE), the mechanism is not specific to IP (although the actual network-side transport is always over IP) and other L2 protocols than PPP are sometimes supported. There is no reason why smartphone has to use Hayes protocol to communicate with baseband (and thus this mechanism), but many do.

Replying to OP because it's the most logical place to put this -

I'm curious what a "USSD code" is, and what kinds of codes I could input into the dialpad that do interesting things.

(I'm already aware of standard telco features like call forwarding, and I know iOS and Android both have their own set of "easter eggs" accessible via the dialer. I'm talking specifically about non-secret codes that talk to the baseband and stuff like that, if this sort of thing exists.)

The wikipedia page answers all your questions https://en.wikipedia.org/wiki/Unstructured_Supplementary_Ser...

Thanks so much! That was a really interesting read.

Yes, definitely. Most LTE modems are derived from 3G modems, and support 3G and 2G as fallback. That is not great for security, because 2G encryption is weak and broken.

It was such an odd joy when I had a Nokia n900, and I realized that you could thether by using wvdial, the same program I used in the 90s to dial into my isp when I couldn't be bothered to figure out pppd chat scripts...

I love how the modem control codes leaked across layers. So many scripted IRC clients had an option to send a quick "+++ATH0" to everyone and hopefully disconnect their crappy modems.

Lol talk about a walk down amnesia lane. I'm now remembering a time I embedded a couple hundred ASCII bell characters in a war script to knock other highschool kids offline. Nothing would clear a chat faster at 2am than computers making a really loud noise that unplugging the speakers wouldn't stop. Ahh nostalgia.

All the cool kids attach the power LED to the speaker headers, to stop your bell script :P

Nice try. BITD the bell triggered a piezo buzzer soldered directly to the motherboard. Speakers had nuthin to do with it.

By the time I was on IRC, most people were using PC speakers, which were real speakers at the time. These days, you get a garbage piezo with your case if you're lucky.

Either way, the power led is useless, so better to hook it up to the speaker header ;)

> * ASCII codes for those single and double box characters, so I could draw a fancy GUI on those old IBM text monitors

Presumably not ASCII - they'll be from some extended IBM character set (CP437?), I would think.

You are indeed correct. I had an old IBM PC/XT manual I believe, which had the charts at the back that I always used to refer to. There were the standard ASCII chart, and another extended chart with the IBM specific set.

dBase III blew my young mind with how it would let you teach it new words for the data you wanted to get out of it. The UX still stands out in my mind as unbelievably good. I should probably see if I can dig out an old copy and find if it's as good as I remember.

Escape codes for HP Laserjets

<esc>&l1O to switch to landscape :)

I'm just about to write some code to parse HP PJL so you never know when ...

Back in 1985 I wrote a HP PCL to HPGL translator in C. Fun stuff!

PJL is easier to parse than it looks at first glance. I worked on a laser printer controller back in the late '80s that for convenience we made mostly HP compatible. Have fun!

Add to that the z80 assembly language instructions I used most often - for patching infinite lives in games. (JMP, JZ, NOP, and RET).

Great list. How about...

* Lotus 1-2-3 "slash" commands

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