Tektronix 4170 Local Graphics Processor

I recently acquired a Tektronix 4170 Local Graphics Processor and 4108 terminal from ebay. Here are some photos of the 4170 and 4108 on Picasa. The 4170 was introduced in 1984 by Tektronix.

The IBM PC had already been around for some time and I imagine it was beginning to make competition for Tektronix in the area of its graphics terminals and workstations. The 4170 appears to be a response to those market forces: its consists of an 8086 CPU and an 8087 FPU pair. Before the 486 contained an integrated FPU, most people did not spend the money for the floating-point processing hardware. Including the FPU into the base design of the 4170 told you that it was meant for real computation and not just business processing that could easily be done entirely in integer arithmetic. No, the 4170 was intended for the kinds of simulation and design problems that required floating-point computation from the CPU and graphics display for the user. The 4170 used a connected Tektronix (or compatible) graphics terminal for its display output and user input. Tektronix terminals intended for use with the 4170 contained a directional joystick built directly into the keyboard for graphical input and could be used similarly to a mouse. You could leverage your existing Tektronix graphics terminal and turn it into a local graphics workstation, running applications on the 8086. The operating environment consists of CP/M-86, along with a custom graphics extension to CP/M-86 called GSX.

This thing was pretty big and the seller was only offering local pickup for shipping. Since the seller was in a city serviced by Craters & Freighters, it was a simple matter of arranging shipment through them. They packed up the terminal, keyboard, workstation and an Epson FX-286 printer into one of their “custom boxes” and freight shipped it to me. Their “custom box” is essentially a double-walled cardboard box cut custom to fit your item and stapled together with heavy duty metal staples, each about 2″ long. The inside of the custom box is lined with 1/2″ of polystyrene cut to match the box. Additional polystyrene is used to fill voids and may be kept from shifting with a little packing tape. The “box” is a tube with two lids. Each lid folds over the edge of the box by about 4″. The lids are stapled firmly to the two ends of the tube. The result is something that is quite sturdy, has adequate dunnage to prevent any damage from shifting during handling. Of course, nothing is really going to protect your valuables if they run a forklift through your box. I’ve used the “custom box” strategy with C&F four times now and it has really worked out great. Craters and Freighters make their business by paying attention to how your items are handled. I’ve had poor results with other freight packing service companies.

Unlike the IBM PC which contained the CPU circuitry on the motherboard, the 4170 contains a backplane into which cards are inserted and the CPU and its support circuitry is implemented on one card. RAM is organized onto either one or two cards, with the second card being optional. My machine has the second card indicating it has more than the base configuration of RAM. An interface card provide the serial RS-232 interfaces to the terminals and peripherals and a floppy disk controller interface card provides access to the floppy drives. This unit appears to have an integrated hard drive as well. I can see some cobwebs and dust inside the machine, but other than a little dirt and a few cosmetic blemishes to the paint job on the cabinet, it appears to be in fine working order. I see no deteriorated foams or “goo” from rubber components, so that’s good. Of course, it was stored in Oregon all these years, who knows what will happen to it now that its going to dry out in the desert. I do have an operator’s and service manual for the 4170, so if I need to do some repairs it shouldn’t be too hard. Aside from the CPU and FPU, most of the chips are SSI or MSI TTL, which is characteristic of products made in the mid 1980s. Quickly scanning date stamps on one of the memory boards showed that the board was manufactured from components made in late 1983. (Many ICs are labelled with a four-digit date code consisting of a two digit year and a two digit week within the year, so 8350 means the 50th week in 1983.)

The machine came with some floppies as well, but unfortunately only one or two out of a box of ten was labelled. The hard drive and floppy drive contents will need to be backed up (and possibly any ROM contents as well) before any serious playing with this machine begins. I can use kermit to transfer files across the communication lines and the floppy drive to exchange files between systems. A number of floppy copy programs purport to be able to deal with the floppy disk format used by the 4170. A small manual for “TekniCAD”, Tektronix CAD software, was included with the 4170. This might imply that TekniCAD is located on one of the floppies or on the hard drive. If so, that will be a good representative of period CAD software on the low end of the capability scale.

One Response to “Tektronix 4170 Local Graphics Processor”

  1. Florent Van Vlasselaer Says:

    Got one fully operational 4170 with CPM86 ,floppys , spares and all the
    servive department’s microfilms plus 3 x 4208 graphic terminals.
    Interested ? Mailme B25-florvv@skynet.be

    Like


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