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Tektronix DF1
Display Formatter
DF1 front panel

Compatible with 7D01

Produced from 1976 to 1985

ROM Images
(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix DF1, introduced in 1977, is a "display formatter" for use with the 7D01 logic analyzer. It adds "data domain displays" (binary, octal and hexadecimal state tables, and a function map display) to the 7D01's time-domain display. It can store a reference table, to which the captured data can be compared. The DF1 was introduced in 1977.

The Tektronix DF2, introduced in 1978, is the same as the DF1 with the exception of an added front-panel "Menu" key and an additional ROM (on a daughter board) that supports GPIB and ASCII modes.

The DF2 does not have a GPIB interface, it can only analyze external GPIB traffic. For this purpose, a 103-0209-00 GPIB to probe comb adapter was supplied with the DF2, which connects GPIB DIO1..DIO8 to CH8..CH15, DAV to the CLOCK input, ATN to CH7, EOI to CH6, SRQ to CH5, and REN to CH4. GPIB signals DAV, NRFD, NDAC and IFC brought out to pins on the connector. CH3..0 are user defined inputs that can track any of these signals, or others as needed. For GPIB analysis, bus data is acquired synchronously using the negative-going edge of the GPIB DAV (Data Valid) line as an external clock.

From TekScope V.8 N.4 1976:

Project manager for the DF1/DF2 was Murlan Kaufman, with Dave Lowry and Jeff Bradford doing the electrical and software design, and Ed Wolfe doing mechanical design. Roy Kaufman and Joe Gaudio, Evaluation Engineers, and Dave McCullough, Marketing Program Manager, also made valuable contributions. Special thanks are due to Jack Lyngdal and Nick Colvin, Manufacturing; Betty Spohn, ECB; Jan Bowden, Prototypes; and to everyone else who contributed to a a speedy, efficient completion of the project.

Key Specifications

Memory One reference table memory, 1kB, same as 7D01 capacity (max. 16 channels at 254 bits/ch), plus 1kB display RAM
Display modes

7D01/DF1 or DF2

  • Timing: Standard 7D01 display – 4, 8 or 16 bits
  • State table: Hexadecimal, octal, or binary formats; two tables (reference, 7D01 memory) of 17 lines of 16-bit words
  • Map: Dot display of the 16 data channels in X-Y coordinate points. Each dot location represents one possible combination of up to 16 inputs to the 7D01.


  • GPIB: Displays 17 lines of decoded GPIB operations and/or ASCII data, and up to four user-defined input signal states.
  • ASCII: Displays 17 lines of decoded ASCII character along with its binary, octal, or hex value, in either 8– or 16–bit modes.
Reset output Positive 100 μs pulse, ≤0.4 V / ≥2.4 V


An internal jumper allows the user to select the source of the on-screen readout in timing diagram mode, which can be either the mainframe readout supplied by the 7D01, or superimposed by the DF1/DF2. The latter is the standard setting and allows the DF1/DF2+7D01 combination to be used in mainframes without readout, e.g. the large-screen 7603N.

The DF1/DF2 has no direct connection to the scope mainframe, it attaches to the 7D01 through a 50-pin D-sub connector on the right side panel only. The DF1/DF2 and 7D01 are mechanically coupled by three nylon standoffs that slide into cutouts in the 7D01's case rails. The bottom two standoffs are fixed and are inserted first, then the connector is plugged in and the third, sliding, stand-off at the top is moved to its locked position.

The DF1/DF2 is built around a Motorola 6800 microprocessor with two (DF2: three) 2K×8 masked ROMs and sixteen 1K×1 SRAMs (Intel 2102).

The DF1, DF2 and 7D01 are often affected by bad TI IC sockets and/or ROM failures, see the Repairs tab.

Memory map

Address (hex) Use
0000-007F Scratchpad RAM (U274, Motorola 6810A)
0080-00FF I/O registers
4000-47FF ROM U820 on DF2 expansion board (156-1132-00, 2k×8, 6831B)
4800-4FFF ROM socket on DF2 expansion board, unused
5000-57FF ROM socket on DF2 expansion board, unused
5800-5FFF ROM socket on DF2 expansion board, unused
6000-63FF 1k RAM
8000-63FF 1k display RAM, "write-only"
Axxx Vertical map address register (→ U552, U554)
Cxxx Horizontal map address register (→ U452, U454)
F000-F7FF ROM U294 (156-0900-00, 2k×8, GI RO-3-8316 or Mostek MK31000)
F800-FFFF ROM U284 (156-0899-00, 2k×8, GI RO-3-8316 or Mostek MK31000)