7854: Difference between revisions

Revision as of 19:56, 10 July 2019

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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 project manager for the 7854 was Tom Rousseau.

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
2019 value	$29,360	$33,060

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
A21 Z-Axis
A15
A15
A2
Signal Out Board
A28
A26 Control Logic Board
A26 Control Logic Board
Vertical Switching
A30 GPIB
Aux Reg
A25 Digitizer
Main Interface
Mode Switch
A28 with option 2D (RAM Expansion)
MPU
HV

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 Tek 7854 a32.jpg|A32
 Tek 7854 a19.jpg|A19
-Tek 7854 t1.jpg|T1
+Tek 7854 t1.jpg|A21 Z-Axis
 Tek 7854 a15b.jpg|A15
 Tek 7854 a15.jpg|A15
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 Tek 7854 signal out board.jpg|Signal Out Board
 Tek 7854 a28.jpg|A28
-Tek 7854 a26.jpg | A26
+Tek 7854 a26.jpg |A26 Control Logic Board
-Tek 7854 logic.jpg|Logic Board
+Tek 7854 logic.jpg|A26 Control Logic Board
 Tek 7854 vertical switching.jpg|Vertical Switching
-Tek 7854 gpib.jpg|GPIB
+Tek 7854 gpib.jpg|A30 GPIB
 Tek 7854 aux reg.jpg|Aux Reg
-Tek 7854 digitizer.jpg|Digitizer
+Tek 7854 digitizer.jpg|A25 Digitizer
 Tek 7854 main interface.jpg|Main Interface
 Tek 7854 mode switch.jpg|Mode Switch