Difference between revisions of "VT100"
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| − | [[Image:Vt100 | + | [[Image:Vt100.jpg|200px|thumb|right|VT100 guide]] |
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| − | The | + | The '''VT100''' was a very popular [[EIA RS-232 serial line interface|RS-232]] based dumb [[video terminal]] introduced by [[DEC]] in 1978. It featured [[cursor]] keys, and the ability to place text wherever the programs wished onto the screen. |
| − | {{stub}} | + | The VT100 was so popular it became THE standard for terminals, and [[terminal emulator]]s. |
| + | |||
| + | The VT100 used an [[Intel 8080]] processor, the later VT102 used an [[i8085|8085]]. VT100 clones (and there were many) would use a number of different processors, not necessarily sticking to the original. | ||
| + | |||
| + | Surprisingly the VT100 could not actually handle 9600 [[baud]] full throttle. The serial hardware could, but the screen could not be updated at 960 characters per second. Thus [[flow control]] was essential unless working with a slow system (e.g. an old [[minicomputer]]..). Xon/Xoff was the most common method for flow control on DEC/VT100 systems. To handle the speed problem some people would put the VT100 into [[VT52]] mode (one of the VT series' features) because VT52 processing had less overhead.[1] | ||
| + | |||
| + | On a personal note, those of us seeing a VT100 for the first time way back then were floored by the "smooth scroll" feature.. now that looked nice. Until you realized how slow it became. Obviously those who demanded speed would turn off the smooth scroll mode and use every other measure to improve how fast the terminal could process data (see above). | ||
| + | |||
| + | ===Models=== | ||
| + | |||
| + | * VT100 - 1978 base model. | ||
| + | * VT101 - 1981 cost reduced; no AVO or STP. | ||
| + | * VT102 - 1981 cost reduced; built in AVO and STP. | ||
| + | * VT103 - with Qbus backplane. | ||
| + | * VT105 - VT100 with WG waveform generator board. | ||
| + | * VT125 - VT100 with ReGIS board. | ||
| + | * VT131 - 1982 cost reduced VT132. | ||
| + | * VT132 - VT100 with AVO, STP, and firmware ROMs which support block serial mode. | ||
| + | * VT180 - VT100 with VT18X board, see below. | ||
| + | |||
| + | ===VT180=== | ||
| + | In 1982 DEC introduced a [[Z80]]-based option board which turned the VT100 into a [[CP/M]] microcomputer. | ||
| + | The option board included 64KB of RAM, a floppy disk controller and an extra serial port, in addition to the Z80. | ||
| + | It was also possible to buy a terminal with the option board pre-installed, this configuration was sold as the '''VT180'''. | ||
| + | |||
| + | ===References=== | ||
| + | [1] Discussion on the classic computers mailing list (classiccmp.org) | ||
| + | |||
| + | ===Simulators=== | ||
| + | |||
| + | There are some VT100 [https://gunkies.org/wiki/Terminal_emulator#Terminal_Simulators terminal simulators] that model the hardware and run the original firmware: | ||
| + | |||
| + | * [https://github.com/mamedev/mame/blob/master/src/mame/drivers/vt100.cpp MAME] | ||
| + | * [https://www.pcjs.org/machines/dec/vt100/ PCx80] | ||
| + | |||
| + | ==External links== | ||
| + | |||
| + | * [http://bitsavers.org/pdf/dec/terminal/vt100/EK-VT100-TM-003_VT100_Technical_Manual_Jul82.pdf "VT100 Series Video Terminal Technical Manual"] - explains the VT100 hardware. | ||
| + | * [http://bitsavers.org/pdf/dec/terminal/vt100/MP00633_VT100_Schematic_Feb82.pdf "VT100-0 Field Maintenance Print Set"] - schematics. | ||
| + | |||
| + | {{semi-stub}} | ||
| + | |||
| + | [[Category: DEC Terminals]] | ||
| + | [[Category: Video Terminals]] | ||
Revision as of 08:19, 11 May 2021
The VT100 was a very popular RS-232 based dumb video terminal introduced by DEC in 1978. It featured cursor keys, and the ability to place text wherever the programs wished onto the screen.
The VT100 was so popular it became THE standard for terminals, and terminal emulators.
The VT100 used an Intel 8080 processor, the later VT102 used an 8085. VT100 clones (and there were many) would use a number of different processors, not necessarily sticking to the original.
Surprisingly the VT100 could not actually handle 9600 baud full throttle. The serial hardware could, but the screen could not be updated at 960 characters per second. Thus flow control was essential unless working with a slow system (e.g. an old minicomputer..). Xon/Xoff was the most common method for flow control on DEC/VT100 systems. To handle the speed problem some people would put the VT100 into VT52 mode (one of the VT series' features) because VT52 processing had less overhead.[1]
On a personal note, those of us seeing a VT100 for the first time way back then were floored by the "smooth scroll" feature.. now that looked nice. Until you realized how slow it became. Obviously those who demanded speed would turn off the smooth scroll mode and use every other measure to improve how fast the terminal could process data (see above).
Models
- VT100 - 1978 base model.
- VT101 - 1981 cost reduced; no AVO or STP.
- VT102 - 1981 cost reduced; built in AVO and STP.
- VT103 - with Qbus backplane.
- VT105 - VT100 with WG waveform generator board.
- VT125 - VT100 with ReGIS board.
- VT131 - 1982 cost reduced VT132.
- VT132 - VT100 with AVO, STP, and firmware ROMs which support block serial mode.
- VT180 - VT100 with VT18X board, see below.
VT180
In 1982 DEC introduced a Z80-based option board which turned the VT100 into a CP/M microcomputer. The option board included 64KB of RAM, a floppy disk controller and an extra serial port, in addition to the Z80. It was also possible to buy a terminal with the option board pre-installed, this configuration was sold as the VT180.
References
[1] Discussion on the classic computers mailing list (classiccmp.org)
Simulators
There are some VT100 terminal simulators that model the hardware and run the original firmware:
External links
- "VT100 Series Video Terminal Technical Manual" - explains the VT100 hardware.
- "VT100-0 Field Maintenance Print Set" - schematics.
