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7854 (view source)

Revision as of 05:08, 9 October 2023

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* [[Media:Tektronix 7854 Test Point and Adjustment Locations D.pdf  | 7854 Test Points and Adjustment Locations]]
* [[Media:Tektronix 7854 Test Point and Adjustment Locations D.pdf  | 7854 Test Points and Adjustment Locations]]
* [[Media:Tektronix 7854 Schematics D.pdf                          | 7854 Schematics]] (cleaned up)
* [[Media:Tektronix 7854 Schematics D.pdf                          | 7854 Schematics]] (cleaned up)
'''Application Notes'''
* [[Media:Tek_AX4864_7854_keyboard_guide.pdf            | Waveform Processing Keyboard Guide]] (OCR)
* [[Media:Tek_AX4281_7854_measurement_variety.pdf        | 7854 Measurement Variety]] (OCR)
* [[Media:Tek_AX4440_7854_onboard_digital_processing.pdf | 7854 Onboard Digital Processing]] (OCR)
* [[Media:42W-4416-1.pdf                                | Using the 7854 in a GPIB configuration]]
* [[Media:42W-5334.pdf                                  | 7854 Automated TDR testing]] (OCR)
* [[Media:42AX-4682.pdf                                  | 7854 Programming Techniques]] (OCR)
* [[Media:Tek 7854-AN-SPSBasic.pdf                      | Talking to the 7854 scope with TEK SPS BASIC]] (''[[Handshake]]'', Winter 1980/81)
* [[Media:7854 Application Programs.pdf                  | 7854 Application Programs]]
* [[Media:Tek_AX4382_7854_wp1310_01.pdf|WP1310 Waveform Processing System]] (OCR)
* [[Media:Tek_AX4425_7854_WP1310_02.pdf|WP1310 Signal Processing System]] (OCR)
* [[Media:Tek_7854_42W6767_tdr_mps_package_sm.pdf|7854TDR and 7854MPS package]] (OCR)
* [[Media:Tek_42W67321_Tekmap_7854_measurement.pdf|TekMAP 7854 Measurement Software]] (OCR)


'''Modifications'''
'''Modifications'''
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{{EndSpecs}}
{{EndSpecs}}


==Internals==
==Application Notes==
The acquisition system uses what Tektronix termed a "display-oriented random sampling digitizing technique".
{{Documents|Link=7854|Class=Application Note}}
 
* [[:File:Tek 7854-AN-SPSBasic.pdf  | Talking to the 7854 scope with TEK SPS BASIC]] (''[[Handshake]]'', Winter 1980/81)
It simultaneously digitizes a pair of X and Y signal values at a rate of 3.5 µs/point, using sample/hold circuits based on Schottky diode bridges, 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 (direct memory access, i.e. bypassing the CPU).
 
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.
 
The firmware consists of mask ROMs, an FPLA, and patch EPROMs.  These ROMs (particularly the early ones from Mostek) are a common point-of-failure. Several remedies exist, see the [[7854/Repairs|Repairs]] page.


==Prices==
==Prices==
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* [https://vintagetek.org/7854-mostek-mkb36000-rom-repairs Mostek ROM Repairs @ vintagetek.org]
* [https://vintagetek.org/7854-mostek-mkb36000-rom-repairs Mostek ROM Repairs @ vintagetek.org]
* [https://paulcarbone.com/blog/tektronix-7854/ overview of ROM repair options @ paulcarbone.com]
* [https://paulcarbone.com/blog/tektronix-7854/ overview of ROM repair options @ paulcarbone.com]
==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 sample/hold circuits based on Schottky diode bridges, 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 (direct memory access, i.e. bypassing the CPU).
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.
The firmware consists of mask ROMs, an FPLA, and patch EPROMs.  These ROMs (particularly the early ones from Mostek) are a common point-of-failure. Several remedies exist, see the [[7854/Repairs|Repairs]] page.


==Pictures==
==Pictures==
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