7854: Difference between revisions

Revision as of 20:34, 6 March 2018

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400 MHz waveform-processing scope

Produced from 1980 to 1990

Manuals

(All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

The Tektronix 7854 Waveform Processing Oscilloscope, introduced in 1980, is a 400 MHz combined analog / digital mainframe in the 7000 series that takes two vertical and two horizontal 7000-series plug-ins. In addition to a conventional analog (real time) scope, it contains an equivalent-time sampling 10-bit digitizer and a programmable waveform processor with GPIB interface.

The waveform processor can be programmed using a detachable calculator-style keyboard, using postfix operators ("reverse Polish notation" like HP calculators) that operate on entire waveforms, not just individual numbers.

Key Specifications

Bandwidth	(analog) 400 MHz
Fastest cal. sweep	500 ps
Sample rate	500 kHz (stores repetitive waveforms up to 400 MHz)
Resolution	10 bit
Acquisition depth	128, 256, 512 or 1024 points
Memory capacity	2048 waveform points in up to 16 waveforms (optional expansion to 5120 points and 40 waveforms)
Single shot	events and pretrigger up to 50 µs/div ("2.5 µs/point") with the 7B87 Time Base
CRT	154-0644-05, P-31, or 154-0893-09, P-11
Features	Signal Averaging Cursor measurements Waveform parameter measurements GPIB Interface (Standard) Waveform calculation operators - add, multiply, square root, log, abs Internal RPN programming language (Reverse Polish Notation) Keystroke Programming (Up to 2000 Keystrokes with Option 2D) programmable text display on screen

Internals

The acquisition system uses what Tektronix termed a "display-oriented random sampling digitizing technique". It simultaneously digitizes a pair of X and Y signal values at a rate of 3.5 µs/point, using Schottky diode bridge based sample/hold circuits and a single 10-bit successive-approximation ADC. The Y sample value is then written into the memory location addressed by the X value, using DMA.

The CPU in the 7854 is a Texas Instruments TMS9900 16-bit microprocessor, known from the infamous TI-99/4 home computer of the late 70s, with 32+6KByte ROM and 8KByte RAM.

Software

Prices

Year	1981	1990
Catalog price	$10,500	$17,000
2016 value	$27,900	$31,400

Links

Pictures

Tektronix 7854 with Waveform Calculator keyboard, 7A26, 7M13, 7D15, 7B87
Waveform Calculator Keyboard
Digital section in the 7854
7854 Vertical Amp Board
7854 Horizontal Amp Board
Rear
A32
A19
T1
A15
A15
A2
Signal Out Board
A28
A26
Logic Board
Vertical Switching
GPIB
Aux Reg
Digitizer
Main Interface
Mode Switch
RAM Expansion
MPU
HV

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 ==Pictures==
 <gallery>
-File:tek7854-with-keyboard.jpg|Tektronix 7854 with Waveform Calculator keyboard, [[7A26]], [[7M13]], [[7D15]], [[7B87]]
+tek7854-with-keyboard.jpg|Tektronix 7854 with Waveform Calculator keyboard, [[7A26]], [[7M13]], [[7D15]], [[7B87]]
-File:Tek_7854_keyboard.jpg|Waveform Calculator Keyboard
+Tek_7854_keyboard.jpg|Waveform Calculator Keyboard
-File:Tek7854 digital boards.jpg | Digital section in the 7854
+Tek7854 digital boards.jpg | Digital section in the 7854
 Tek 7854 vertical amp.jpg|7854 Vertical Amp Board
 Tek 7854 horizontal amp.jpg|7854 Horizontal Amp Board