32
votes
Why did the VT100 terminal have to be connected to a host computer if it already had a processor?
"Having a processor" is not sufficient for something to be a general purpose computing device. The VT100 was designed for a specific purpose, and adding more features like storage and I/O ...
- 6,849
31
votes
Accepted
What is the difference between the "Return" and "Enter" keys in the VT100 terminal?
Under normal circumstances, there is no difference (RETURN and ENTER will send CR or CR LF as configured by the New Line Mode). However, there is a mode called "keypad application mode" ...
- 6,849
30
votes
Did terminals (e.g. VT100) require a terminal driver on the host computer?
Different terminals didn’t (and don’t) use different kernel-level drivers. In Unix-style systems, the kernel does provide some terminal-related features, called line disciplines and the TTY layer ...
- 118k
23
votes
Accepted
Computers with integrated monitor (all-in-one form factor)
It's a little cheaper to build all-in-one units because you only need one cabinet and one power supply, and you need fewer cables and connectors and supporting electronics.
And back then, people didn'...
- 17.4k
16
votes
Why did the VT100 terminal have to be connected to a host computer if it already had a processor?
The 2MHz Intel 8080 ran at 290 thousand IPS (instructions per second), whereas the VAX 11/780 that a VT100 plugged into ran at 1,000 thousand IPS (aka 1 MIPS). Thus, 3+x faster.
Just as importantly, ...
- 688
15
votes
Why did the VT100 terminal have to be connected to a host computer if it already had a processor?
So why did it have to be connected to a host computer? Why not use its processor to perform computations?
Because a VT100, or terminals in general, are dedicated devices for a specific purpose. ...
- 213k
14
votes
What happens when a terminal (like a VT100) is connected to a computer?
Does this mean that everything must be already set up for the user login on this port? Like a TTY driver already listening on the port, the login process already running,
Exactly. In every system I'...
12
votes
Why did the VT100 terminal have to be connected to a host computer if it already had a processor?
Digital did make a standalone VT100, but it didn't use the built-in 8080. It used a 12-bit Intersil 6100 CPU chip and could run PDP-8 programs such as WPS-8. It was called the Digital DECmate VT278.
- 1,459
10
votes
Did terminals (e.g. VT100) require a terminal driver on the host computer?
This was not done by a “driver” at the OS level as you are thinking of it.
In Unix, there were drivers that dealt with the RS232 interface and these were surfaced as /dev/tty* devices and dealt with ...
- 3,264
10
votes
Did terminals (e.g. VT100) require a terminal driver on the host computer?
"It depends".
I'm answering this in the context of DEC timesharing systems, since that's the natural habitat of a DEC VT100.
There's a hardware device such as a DZ11 terminal multiplexer (8 lines) ...
- 33.5k
10
votes
Could we change the baud rate for the two serial ports on a terminal and on a computer?
The short answer is yes. You can change the baud rate of a VT100 talking to a PDP-11.
On the VT100, this is simply done using the Set Up facility. This is entered using the Set Up key on the top ...
- 8,031
9
votes
Why did the VT100 terminal have to be connected to a host computer if it already had a processor?
At the beginning of the '70s it was more the limitations of memory than the processing power that was what was a terminal or what was a computer. You can see it when you study what early glass ...
- 3,649
7
votes
Computers with integrated monitor (all-in-one form factor)
Most of the problems that you list were simply not considerations in the mid-70's.
The Commodore PET was not hard to lift safely. Its monitor (in the 40 column variety at least) was tiny and didn't ...
- 11.4k
6
votes
Can escape sequences be entered directly from keyboard to terminal for VT100 and similar?
Well, as usual with complex matter the answer is a mixture of Yes/If.
First of all, are these assumptions correct?
Yes, the assumptions stated are perfect good and correct. In general. In detail ...
- 213k
6
votes
Accepted
Behavior of DECDHL on single lines
What did real VTxxx do?
Certainly the VT220 does the same as what xterm does. It just shows the top or bottom half of the character. I don't recall this behaviour depending on the emulation mode.
I'm ...
- 38.2k
6
votes
Why did the VT100 terminal have to be connected to a host computer if it already had a processor?
What would you do with it? Its only connection was an RS-232 serial port, which connected it to a mainframe or minicomputer. It didn't have a disk for program storage, or even a cassette interface ...
- 1,695
5
votes
Accepted
Using MAI DT4315A as a terminal for RaspberryPI or other linux system
The RJ45 standard just defines which RS232 signal is on which pin of the connector.
If your RPi has a genuine RS232 output interface, you don't need to do any more level shifting because that will ...
- 6,646
5
votes
What happens when a terminal (like a VT100) is connected to a computer?
First of, this question is impossible to be answered in a general context, so the assumption of a Unix(oid) system will prevail. Second, even in a Unix(oid) environment variations are way too large ...
- 213k
5
votes
What happens when a terminal (like a VT100) is connected to a computer?
If the line is using modems, then the modem knows when you've called it (carrier detect), and after some handshaking, signals the host OS that the line is now connected. Alternatively, for hardwired ...
- 33.5k
5
votes
What does bold reverse video look like on a VT100/VT102?
The approach I remember liking on some terminals of that era that I liked (not sure if I noticed DEC ones doing this, or some other company's) was that there were four intensity levels (including off)....
- 34.7k
5
votes
Did terminals (e.g. VT100) require a terminal driver on the host computer?
Two more slightly different situations from the past (well, everything in Retrocomputing is from the past...):
3270 Emulation
When I was at the University of Maryland, College Park in the early 1980s, ...
4
votes
Did terminals (e.g. VT100) require a terminal driver on the host computer?
I guess that's a field one can come up with many views - and all presented answers so far give a valid view with lots of additional information. This is intended to break it down to a more general ...
- 213k
4
votes
Computers with integrated monitor (all-in-one form factor)
Indeed, the PET likely took a lot of design ideas from "dumb" (actually semi-intelligent - very few of these weren't simple microcomputers inside!) terminals of the 70s, and kept the non-detachable ...
- 5,660
4
votes
Behavior of DECDHL on single lines
Text-based VT-series terminals divide the screen into horizontal stripes whose height is that of a single text line, and generate the video output for each stripe independently. Once a stripe is ...
- 34.7k
4
votes
Why did the VT100 terminal have to be connected to a host computer if it already had a processor?
Sharing
This is hinted at in other answers, but it really is the key. There were two ways that a video terminal (or a Teletype, for that matter) could be used:
Single User
A terminal could be a ...
3
votes
Did terminals (e.g. VT100) require a terminal driver on the host computer?
The DEC VT100 itself did not have a driver. When you connect a terminal like a VT100 to a serial port it was a just tty device.
VAX/VMS used a utility to configure devices for the operating system. ...
3
votes
Computers with integrated monitor (all-in-one form factor)
Three other reasons are conserving space, design aesthetics, and portability. The original Macintosh was an example of how to use the form factor for portability, you could get a fabric carrying case ...
3
votes
Did terminals (e.g. VT100) require a terminal driver on the host computer?
We have to distinguish between different cases, but in most cases the answer seems to be "no":
In "early" systems (like the Altair 680 in home computing or 1960s professional computers) programs ...
- 3,389
2
votes
Can escape sequences be entered directly from keyboard to terminal for VT100 and similar?
Originally, the escape character was used to initiate multi-character sequences when it was necessary to support more functions than could be accommodated in 31 active control characters (codes 0x00 ...
- 34.7k
2
votes
Can escape sequences be entered directly from keyboard to terminal for VT100 and similar?
Short answer is yes.
https://www.pcjs.org/devices/pc8080/machine/vt100/ has a vt100 emulator.
Once you've selected the "emulator" screen press:
F9 - Enter setup
4 - Toggle local/online to local (...
- 5,277
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