Joe's HP 98x5 Series Interfaces web page

Revised 10/19/2000

This site still under construction

HP 98x5 Peripherals.

HP 9111A graphics tablet. Replaced the 9874 Digitizer but did not tilt since it uses an electro-static charge to hold the drawing. Uses HP-IB interface.

HP 9862A Plotter. This was one of the old slope front X-Y plotters that was widely used with the HP 9820 and 9830 calculators. It was replaced with the HP9872 plotter.

HP 9866 printer. This printer was available as stand alone version or as a special version that fit directly on the top of the 9830 calculator. It printed on 8 1/2" wide thermal roll paper. It could print a full 80 character width using 5 x 7 dot matrix characters at 240 lines per minute. It could also print simple plots and tables or other formatted text. The "B" version of this printer was introduced in 1977 and it added the capability of printing both upper and lower case letters and vertical lines. The 9866 printers used a parallel interface but with a special connector (option 066). The 9830 version of this printer used a short cable that connected to a special socket on the back of the 9830.

HP 9871 Impact Printer. This printer used a 96 character daisy wheel to print. It featured both horizontal and vertical motion control so it could be used to plot using characters.

HP 9872 plotter. This was a large flat bed plotter that replaced the 9862. Besides an improved mechanism, better accuracy and an improved plotter language, the 9872 could also be used as a digitizer as well as a plotter. The 9872 C plotter held eight pens that could be swapped under software control. For people that did lots of plotting, the 9872 T was available. The T model was generally the same as the C model but added a large paper handling mechanism to each end of the plotter and used roll paper instead of individual sheets. One end held the paper roll feed mechanism and the other contained a shear to cut off each drawing as it was finished and replaced by fresh paper. Uses HP-IB interface.

HP 9874 digitizer. The digitizer used a vacuum table to hold drawings and could be tilted upright to nearly any angle and used arms in back to support it. It used a "puck" with an optical sight and two buttons to digitize points and input their coordinates to the system. There were also a number of programmable keys on the right hand side of the table. It could be used to digitize single points or could be used continuously to measure distances. It connected to the system via HP-IB and could be used with the HP 1000 computer and HP 2674 Intelligent Terminal as well as the 9800 series calculators.

HP 9875A Cartridge Tape Unit. This box contained one or two tape drives with a capacity of 225K bytes each like those used in the 98x5 series calculators. It used a HP-IB interface and could be used on any machine that supported an external disk drive. It was intended as a low cost substitute for a disk drive.

HP 9876A. The 9876 was a fast quiet printer that used thermal fan-fold paper. It was much smaller and lighter than the 9866 printer and could print 480 lines per minute. It also used a 7 x 12 dot matrix for each character and allowed the user to define their own characters. It contained seven built in character sets. Use of the larger dot matrix allowed true descending characters, over size characters, over lines and under lines. It also could be used to print raster graphics with 560 dots per line. It was available for use with HP-IB, parallel or RS-232 interfaces.

HP 9877 Tape Memory unit. This is a very strange device that only appeared in the 1977 HP catalog. The ones that I have are the only ones that anyone has found. It has four tapes drives and it supposed to be capable of copying tapes in a standalone mode but I have never been able to find any information on it. It looks like it uses a parallel interface but I don't know what the pignut is.

HP 9878A I/O expander. Development code name "Spice Rack". This box plugged into the I/O slot of a 98x5 system via a cable and contained seven I/O slots. Up to four of these could be connected to each 98x5 calculator and each provided six additional I/O slots but only 14 devices could be connected due to addressing limitations.

HP 9884A Tape Punch. A paper tape punch that operated at 75 characters per second.

HP 11310A (???) Card Reader. This reader read marked or punched 80 column Hollerith cards.

HP 9885M/S 8" SS SD floppy disks drive, each drive could hold approximately 500k bytes, required special options.

HP 9895A Dual DS/DD 8" floppy drive with a capacity of 1.15 Mb per disk, uses standard (but dedicated) 98034 HP-IB interface.

HP 98x5 Interfaces

HP 98032A 16 bit parallel interface. Development code name "Parsley". Both a general purpose interface and many special options to connect to special devices such as tape punches, HP 9866 printer, etc. that used parallel I/O.

HP 98033 BCD Interface. Development code name "Sage". Mainly used for older instruments that shifted data in and out one character at a time. It uses BCD for ease of interfacing and to avoid round off in hexadecimal conversions.

HP 98034AHP-IB interface. Development code name "Rosemary". IEEE-488. THE standard HP interface after about 1973.

HP 98035A Real Time Clock. Development code name "Thyme". Supplies battery backed up real time clock and calendar data. Also has four independent timers that can be used to generate software interrupts. With optional cable (option 100), it could send interrupts to external devices or external devices could generate software interrupts.

HP 98036A Serial card. Development code name "Cap'n Crunch". Mainly used for communications to terminals and other computers. Allows communications over relatively long distances. With the 9825 System Programming ROM (HP 98224) and this interface, the 9825 could be used as a terminal or it could use a remote keyboard.

HP 98037A A/D card. Development code name "Prism". This interface was announced but never sold. The story goes that HP killed the 98037A because the Hybrid-based 98x5 series desktops were at the end of their life by the time the 98037A was introduced and HP didn't want the support headaches. The 98037A was a year late to market because just as it was about to go into production management demanding that that engineering eliminate all of the trimpots (there were 3) in the original A/D design. Engineering did redesign the analog section using some very cool laser-trimmed resistor technology from LID, but it cost a year, and ultimately, the project. HP used a MOSTEK MK3870 microcomputer (a 1-chip version of the Fairchild F8) to run the 98037A A/D interface. They had to use the 3870 because it was the only commercial microcontroller with a low enough power consumption to work in one of our interface cards. (CMOS didn't exist as a viable LSI technology back then.)

HP 98040 Incremental Plotter interface. Used to operate the OLD! pre-HPGL plotters. It was designed for a line of very dumb (pre-internal processor) plotters that were available at the time. The interface consisted of stepper-motor interfaces and limit-switch feedback. The computer, through the interface, was responsible for stepping the plotter pen in X and Y dimensions using the interface. The computer had to keep track of where the pen was, because the only position feedback available was from the limit switches. So, for initialization, you slewed the pen to a corner (perhaps lower left) and when the limit switches activated, you knew you were at location 0,0. From there, you ran the plotter open loop.

HP 98041A Disk interface. More than just an interface. This is a large box that has a cable that plugs in like an interface. The box has one HP-IB port on it and is used to connect to a large variety of HP hard drives and tape drives.

HP 98046 Data Communications Interface. No details available.
Just as a note, the HP-9815 interfaces were unique that that machine and could not be used on any of the other HP calculators. See the HP-9815 page for more details.

AND finally here I am still hard at work!

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