HP 9800 Series Computers Description (working copy )

Created 7/19/99

rev 1. More development code names, more about the high performance CPU option in the 9845, more about the various monitors for the 9845 and more peripherals and interfaces added.
rev 2. same day. Finally found a little info about the HP 9831. Added it.
rev 3. Added hardware description of the high performance HP 9845 BLP. Added code names of interfaces and added more 9830 interfaces.

Last Modified 8/13/99

HP 9810, 9820, 9830 Series

The HP 9810, 9820 and 9830 were all announced simultaneously by HP in the December 1972 HP Journal. The 9810, 9820 and 9830 were all four bit machines and all of them used a serial bus internally.

HP 9810

The 9810 used a three line LED display that displayed the X, Y and Z registers in a manner similar to the HP 9100. Here is a good picture of a 9810 courtesy of Alex Knight. The 9810 measures 21" long x 17.75" wide x 5.75" tall. The 9810 used RPN and the standard model could hold up to 500 program steps and 51 data storage registers of memory and had a built in magnetic card reader. A built-in thermal printer was available as an option but it would only print numeric characters unless a ROM that contained the alphanumeric Printer ROM was added. The ROMs for the 9810 were in the form of a block that plugged into the left side of keyboard. Each block had it's own keys and key labels. Several blocks were available that contained more than one ROM.

9810 options
Option 015 Carrying Handle $25
Option 001 111 Total Data Registers $400
Option 002 1012 Total Data Registers $500
Option 003 2036 Total Data Registers $850
Option 004 Printer $675

9810 ROMs
HP 11210A Mathematics $485
HP 112111A Alphanumeric Printer Plug-in $485
HP 11212A Typewriter $225
HP 11213A User Definable $485
HP 11214A Statistics $485
HP 11215A Plotter $485
HP 11261A Plotter and Alpha Printer combination $800
HP 11262A Peripheral/Cassette Combination $625
HP 11264A Peripheral $485
HP 11265A Cassette Memory $225
HP 11266A Peripheral/Alpha Printer Combination $800
HP 11267A Typewriter/Cassette Combination $450

Price (1973) 9810A $ 2,475
(1976) 9810A $ 2,075

HP 9820

The 9820 used a formula oriented language called HPL (Hewlett Packard Language). HPL was HP's version of the then widely popular APL language. HPL allowed subroutine nesting, flags and multi-dimensional arrays of up to the size of the system memory. But the HP 9820 had very limited capability unless optional ROMs were added. For example, a Mathematics ROM had to be added in order to added in order to perform Sine, Cosine, and Tangent functions. There were three ROM slots in this model and they were located on the top left hand side just above the display. There were three groups of keys on the left hand side of the keyboard that were dedicated for use with the ROMs. Each ROM came with an overlay that showed the functions assigned to each key. The standard 9820 model came with 173 registers of memory, a 32 character LED display, a built in 16 character thermal printer and a magnetic card reader.

9820 options
Option 015 Carrying Handle $25
Option 001 429 Total Data Registers $1,250
Option ??? 1453 Total Data Registers

Price (1973) $4,975.
(1976) $4,175

HP 9821

The HP 9821 was first listed in the 1976 HP catalog, although it was previously advertised in ad the January 20 1974 issue of Electronic Design News. The HP 9821 was a HP 9820 with a magnetic tape drive replacing the magnetic card reader. These seem to be very rare, I know of a total of four of them. I have never seen or heard of a manual specifically for this model. This model is the same size and weight as the 9820 and has the same capabilities. It was listed as having only 167 registers instead of the 173 that were available in the HP 9820. The firmware for the cassette drive used the additional six registers.

9821 options
Option 015 Carrying Handle $25
Option 001 423 Total Data Registers
Option ??? 935 Total Data Registers
Option ??? 1447 Total Data Registers

9820/9821 ROMs

HP 11220A Peripheral Control I $485
HP 11221A Mathematics $485
HP 11222A User Definable $485
HP 11223A Cassette, ROM $225

HP 11224A Peripheral Control II $485

Price (1973) $4,975.
(1976) $5,225.

HP 9830

The HP 9830 was introduced in the December 1972 HP Journal. The 9830 was by far the most capable machine of this group and ran what HP called BASIC Plus. The 9830B was introduced four years later in the 1977 HP catalog. HP said that three things set the HP 9830 apart from the other desktop systems: First, it's use of BASIC Plus with it's English like vocabulary and structure, Second, The entire operating system and firmware were in ROM and did not take up any of the read/write memory space. Third, the use of the cassette tape drive with features that they said were only found on large computers. The basic 9830 came with 1760 16 bit words of memory, a 32 character display, the cassette tape drive and a large well-featured keyboard. The HP 9830 had a door in the left side that could hold up to five optional ROMs. In addition, the 9830 could hold three more ROMs internally. The internal ROMs were on cards instead of plug in cartridges and had to be installed by HP. When the internal ROMs or extra memory were installed, a sticker that listed the ROM or new memory size and option number was added to the outside ROM door. The 9830A came with 3520 bytes (1760 words) of memory and could be expanded up to 15808 bytes (7904 words). The B came with 15808 bytes (7904 words) of memory and could be expanded up to 30144 bytes (15072 words). The Matrix and String Variables ROM cards were also standard in the 9830B.

The HP 9830 is commonly found with a special version of HP 9866 printer that sits on top of the 9830 calculator and looks like it's part of the original machine. The 9866 was a full width page printer that printed up to 80 columns of characters on 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 9830 version of the 9866 printer used a short cable that connected to a special socket on the back of the 9830.

The HP 9830 was dropped from the HP catalog after 1977 or 1978. But for what it's worth, I talked to someone in Switzerland that told me that he knows of five companies there that are still using the HP 9830. One of them has been in daily use since 1975!

9830 options
???? Memory expansion to 4k. (9830A) $1,475
Option 001 a total of 15072 16 bit words of Read/Write memory installed (9830B only)
Option 270 internal Matrix ROM card
Option 272 internal Extended I/O ROM card
Option 274 internal String Variables ROM card
Option 275 a total of 3808 15 bit Words of Read/Write memory installed
Option 276 a total of 7904 16 bit words of Read/Write memory installed

9830 ROMs
HP 11270B Matrix ROM $485
HP 11271B Plotter Control ROM
HP 11272B Extended I/O ROM $485
HP 11273B Mass Memory
HP 11274B String Variables ROM $485
HP 11279B Advanced Programming I ROM
HP 11289B Advanced Programming II ROM
HP ?????? Terminal 1 ROM $485

Price (1973) 9830A $ 5,975
(1973) 9866A $ 2,975
(1976) 9830A $ 6,800
(1977) 9830A $ 4,900
(1977) 9830B $ 8,350
(1977) 9866A $ 3,145
(1977) 9866B $ 3,350

Size and Weight: 9830 calculator 25 x 18 x 6 inches 43 pounds
9866 printer 15 x 18 x 6 inches 42 pounds

Some of the 98x0 Calculator Interfaces
11202A 8-bit TTL interface
11203A BCD interface
11204A was used for the 9864A digitizer, and doesn't appear to be a general-purpose I/F that was available for sale
11205A Serial Interface
59405A HP-IB Interface for HP 9830
59405A Option 020 HP-IB Interface for HP 9820
59405A Option 021 HP-IB Interface for HP 9821

Some of the 98x0 Calculator Peripherals
9860A Marked Card Reader
9861A Typewriter Interface
9862A Plotter (covered in the 98x5 peripherals)
9863A Paper Tape Reader
9864A Digitizer (two pieces, an interface box and a digitizing tablet)
9865A Cassette Tape Drive
9866A Printer (covered in the 98x5 peripherals)
9868A I/O Expander
9869A Hopper Fed Card Reader
9870A Card Reader (I think it reads Hollerith punched cards)

A Transition, the HP 9815

HP 9815

The HP 9815 was introduced in the 1976 HP catalog. The 9815 was based on a Motorla 6800 CPU and was the first HP desktop to use a parallel bus internally. All of the machines after the 9815 used the parallel bus. It has many new features including an autostart capability, a ten key numeric keyboard, 15 special function keys, a 16 character LED display and a newly redesigned 16 character printer thermal printer. The tape drive was also a new design and could store 96k bytes. Two I/O channels were optional. It was initially offered with 10 data registers and 472 programming steps and was upgradeable to 2008 steps. The 9815 used RPN logic and had 28 built-in scientific functions. HP introduced the 9815S in 1980. The 9815S replaced the 9815A option 001 and included the two I/O slots and 3800 programming steps as standard. HP dropped the 9815A from the catalog in 1981. The 9815S was dropped after the 1982 catalog.

9815 Options
Option 001 (9815A only) 2008 programming steps
Option 002 (9815A only) two I/O slots

Price (1976) 9815A $ 2,900
(1977) 9815A $ 2,900
(1979) 9815A $ 2,900
(1977) 9815S $ 3,950
(1981) 9815S $ 3,800

Size and Weight: Base 14 x 14x 4 inches 14 pounds

9815 interfaces
HP 98130A is used for the 9872 plotter.
HP 98131A is used for the 9871 impact character printer.
HP 98132A is used for the 9862 plotter
98133A is used for 9 digit BCD input and 8 bit parallel output.
98134A is used for bi-directional 8 bit parallel I/O and can be used to connect the 9815 to other systems.
98135A is used to connect up to 14 HP-IB devices and has no interrupt capability.
98136A is used for RS-232 or current loop serial communications.

The 9825, 9835 and 9845 Series.

Unlike the 9810, 9820 and 9830 series, the 9825, 9835 and 9845 were not all released at the same time. Also unlike the earlier series, the 98x5 series shared many common interfaces and peripherals. The 98x5 series computers all use the new tape drive that was developed to use the 3M DC-100 tapes. HP sold these tapes under part number 9162-0061 These tapes had a metal back plate for additional stiffness and could not be driven via the capstans. Instead there was a drive wheel/pulley on the edge of the cassette that engaged with a rubber drive wheel in the drive. The drive wheel/pulley in turn drove rubber belt that drove the tape capstans.

HP 9825

The HP 9825 was introduced in the June 1976 issue of the HP Journal and was probably the most widely produced of all of HP's desktop calculators. It's development code name was "Keeper" because it was originally going to have a "key per" function like its predecessor, the 9820/21. The low profile keyboard was given the development code name "Cricket" because of the sound that some of the keys made! The 9825 was a third generation machine and featured NMOS hybrid technology, two-level priority interrupt, a live keyboard and direct memory access with input speeds of up to 400,000 16 bit words per second. The live keyboard feature allowed changing variables or program statements while the program is running, or to list the program while it is running. Optional character sets include German, French, Spanish and Katakana. Other features included a high speed bi-directional tape drive with a capacity of 250k bytes, the ability to handle multi-dimensional arrays and an extended number range (+/- 10 ^ 511 to +/- 10 ^ -511). It also featured four ROM slots in the front and three I/O slots in the rear of the case. The 9825 used the formula oriented HPL language and was capable with the HPL used by the HP 9820 and 9821. HPL was HP's version of the then widely popular APL language. HPL allowed subroutine nesting, flags and multi-dimensional arrays of up to the size of the system memory. The 9825 used a 32 character LED display in which each character was made up of a 5 x 7 matrix of individual LEDs. This allowed the machine to displays numeric and both upper and lower case letters. Even thought the display only displayed 32 characters, up to 80 characters could be input at a time. After the 67th character was input, the machine would beep to indicate that it was nearly full. The 9825 allows multiple entries per line. Each entry could be separated by semicolons. The 9825 allowed simple variables but they could only be one character long and were limited to the uppercase letter therefore only 26 simple variables could be used. However it also allowed the use of numbered registers for variable storage. The use of registers also allowed indirect storage of values. For example "20 --> r r10" would store the value 20 in the register who's number was in register 10. The optional Strings ROM also permitted the use of string variables. The 9825 also used the same 16 character printer that was used in the HP9815.

The 9825 was produced in at least three models, the "A", "B" and "T" models. The 9825 technical Specifications dated May 1980 also list a "S" model but I have never seen one and have not found one listed in any of the HP catalogs. The original A version was easily recognized by it use of low profile keys and by the pull out drawer in the right hand side. The ROM drawer contained the operating system ROMs. The B version had many enhancements including the use of full height keys, 23 K of read/write memory plus built-in Strings, Advanced Programming, General I/O, Extended I/O and Plotter ROMs. HP also dropped the pull out OS ROM drawer and built the OS ROMs into the machine in the B model. The T version had all the enhancements of the B model but also included the then new Systems Programming ROM and 61k bytes of read/write memory.

The designer of the 9825 Cricket keyboard designer was Ron Lingeman, who later started Otrona, an early portable CP/M and computer vendor in Boulder, Colorado.

The model markings on the 9825s can be very confusing. It's common for them to have one model marked on the outside but to have another model number listed under the paper cover. I have one that's marked "9825A" on the back label but marked "9825B" next to the display and "9825T" under the paper cover! I have never seen one marked "9825T" on the outside. They are almost always marked 9825B on the outside but under the paper cover they are usually marked "9825T" "Installed devices: 9872A Plotter, General I/O, Extended I/O, Advanced Programming, String, System Programming , Total Memory 61670 Bytes". Strangely, I also have 9825B that says exactly the same thing except that it says "9825B" instead of "9825T" under the paper cover. I'm guessing that it was a prototype for the "T" model. That machine also has a large warning label on outside top warning the user not to install any ROMs other than the 98211 Matrix ROM or the 98217A Flexible Disk Drive ROM. It says that installing any plug-in ROM that is already built into the calculator may damage the machine. I have never seen this warning on ANY other HP machine. The "B" and "T" models weren't the only ones to get labels under the paper cover. I also have a 9825A with the chicklet keys that says "9825A" "Installed devices: 9872A Plotter, General I/O, Extended I/O, String, Advanced Programming, Matrix, Opt 001 15036 bytes, Opt 002 23228 bytes".

One of the more interesting ROMs for the HP 9825A was the HP 98224A Systems Programming ROM. Originally, it was called a "COM ROM" and was conceived of as a support ROM for the more advanced functions of the 98036A, like full-duplex serial I/O and better access to the control and status registers, that were not supported by the original I/O ROMs. The "COM ROM" was intended to replace the HP 11205, HP 11206 and HP 11284 ROMs that were used in the HP 9830 for communications. When used with the HP 98036 RS-232 interface, it allowed the 9825 to be used as a computer terminal and also allowed the 9825 to use a remote keyboard. However as it's development continued more features not directly related to communications were added so it was eventually named a Systems Programming ROM. It proved so useful that the ROM was built into later 9825 T. One of it's more interesting features was the ability of reading in ASCII from anywhere (serial, paper tape, etc.) and converting these to the internal, tokenized program format used by the 9825. They did this by hooking into the same routines used to store a line of code into the program from the keyboard, hence the command syntax "Store A$." Briefly, they took the ASCII, stored it into the 9825's keyboard buffer, and "virtually" smacked the "store" key on the keyboard. They also added the ability to suppress error checking so the results could be "interesting" if the operator made a mistake! Because the 9825 allows you to store a line into a running program from the keyboard, this feature allowed you to write self-modifying programs. Everyone was very nervous about creating a way to write self-modifying code, hence the cartoon showing COM ROM blowing a 9825 apart was circuited within HP. {add link to cartoon!} If you look closely, the 9825 display is saying "Jeeez." Here is a picture of THE original Systems programming ROM {add link!}. Note, the red racing stripes on it! Enough said!

The HP 9825 was dropped from the HP catalog after 1983. HP stated that the replacement for the 9825 was the HP 9826 (AKA 9000 226, development name "Chipmunk") running HPL. But it should be noted that 9816 and 9836A were compatible and could also run HPL. The HPL for the 9000 200 series computers was compatible with the 9825 HPL and HP even referred to the HP 9825 manual for a language reference. The 9000 200 series HPL was available as a disk based system or on plug in ROM cards.

9825 options
Opt 001 15036 Bytes
Opt 002 23228 Bytes
Opt 003 32K Bytes

HP 9820/9821 ROMs
HP 98210A String - Advanced Programming
HP 98211A Matrix
HP 98213A General I/O - Extended I/O
HP 98214A 9862A Plotter- General I/O - Extended I/O
HP 98216A Plotter- General I/O - Extended I/O (some are marked "9872A Plotter- General I/O - Extended I/O"
HP 98217A 9885M Flexible Disk Drive ROM
HP 98224A Systems Programming ROM
HP 98228A Disk ROM {supports both 9885 and 9895 drives}

Price (1977) 9825A = $ 5,900
(1979) 9825A = $ 5,900
(1981) 9825B = $ 7,700
9825T = $ 8,200
(1983) 9825B = $ 8,100
9825T = $ 8,600

Size and Weight: Base 15 x 21 x 5 inches 26 pounds

HP 9831, Neither Fish nor Fowl!

The HP 9831 is a strange machine. It's a cross between a HP 9830 and HP 9825. It was only listed in the 1978 HP catalog. It was listed as a new model that year. The description says that it runs BASIC and has 7162 bytes standard but is expandable to 32k and that it looks like a 9825. The 9831 had the Matrix, String Variables and possibly some of the HP 9830 ROMs built-in. I asked HP about the 9831 and here is what they had to say. "The 9831 used the 9825's hardware and the firmware was a rewrite of the original 9830 code. Many 9830 lovers wanted to be able to program in HP Basic but use the new, much faster hardware and the superior tape storage. I don't think this project required much more than pulling out the 9825 system ROMs and plugging in the 9831 ROMs. In fact, as I recall, some of us kept two system-ROM drawers around so we could change the machine's personality at will." This seems to be a VERY rare machine. I only know of one example that exist. Other than that one appearance in the 1978 catalog, I have never seen it mentioned in any of the HP catalogs or literature. The HP 9835A and B were both released the next year so apparently the HP 9831 was quickly dropped. The 9831 should use the standard HP 98x5 interfaces and peripherals.

Price (1978) = $ ???

HP 9835

AKA System 35. Both the 9835 A and B models were introduced in the 1979 HP catalog but were not available until May of that year. Their development code name was "Raven". The 9835 was released after the HP 9845 and was essentaully a baby 9845B. It had a single processor, that switched between being an LPU and PPU. Interestingly, most programs saw little performance difference. The 9835s were another third generation machine and featured all of advances of the 9825s included the same live keyboard, high speed tape drive and an extended number range plus they added an impressive range of interfacing capability including buffered I/O, DMA, fast read/write, 15 levels of priority interrupts and built in I/O drivers. The 9835s came standard with 64K bytes of read/write memory and 112K bytes of read/only memory. The read/write memory was expandable in increments of 64K to the full 256K bytes. Even though a machine might have 64k of read/write memory, the operating system would use a portion of it so only 49,962 bytes were available on a 9835A and 45,854 bytes were available on a 9835B. The option ROMs also used some of the read/write memory so the amount of memory available could even be less than that listed. A second tape drive was listed as being optional but I think that was a typographical error since there is no room for it in the machine. A sixteen character printer was optional. The 9835s featured HP's Enhanced BASIC. Enhanced BASIC was compatible with ANSI BASIC and featured FORTRAN-like capabilities such as subprograms, multicharacter identifiers, large-scale array operations, line labels and flexible output formatting. The 9835s could be programmed in either BASIC or Assembly Language. Assembly Language offered speed increases of up to 100 times in some applications. They also featured four ROM slots in the front and three I/O slots in the rear of the case.

The ROMs used in the 9835 are rather unusual. The ROM carriers look exactly like the ROMs for the HP 9825 but without labels. But instead of only holding one ROM, each carrier has sockets for four ROMs. The individual ROMs are small square boxes similar to those used in the HP 85. The 9835 ROMs come in sets of 1, 2 or 4 individual ROMs and the ROMs can be mounted in any order in the carrier or in any position in the 9835. The fourteen operating system ROMs are similarly mounted in a pull out drawer on the left side of the 9835. Flash! I've just learned that one collector has a 9835 with ROM drawers that hold six ROMs each instead of four. That's something that I haven't heard of before.

The 9835A and B models were very different. Take a look at this "Overview" from the HP 9835 Preview manual. The 9835A model featured a CRT monitor on top on the machine but the 9835B featured a 32 character LED display like that used in the 9825. The monitor used on the 9835A displayed 24 lines with 80 characters per line. The CRT measured 12 in. diagonally and had a dual raster-scan, P31 green phosphor screen with adjustable brightness. The color, contrast, size and brilliance were chosen for maximum ease of viewing. It also featured inverse video, blinking and underlining that could be used in any combination to highlight selected areas on the screen. Even though the display used on the 9835B only showed 32 characters, the 9835 would accept input lines of up to 160 characters and the display could be scrolled left and right to display any portion the 160 character line.

HP 9835 options
Option 500 was the 16 character printer.
Option 201 128k bytes of read/write memory (115,402 available in the 9835A and 122,294 in the 9835B.
Option 202 192k bytes of read/write memory (180,842 available in the 9835A and 187,734 in the 9835B.
Option 203 256k bytes of read/write memory (246,282 available in the 9835A and 253,174 in the 9835B.

HP 9835 ROMs
HP 98225A Structured Programming ROM (1)
HP 98317A BASIC Data Comm ROMs (set of 4 ROMs)
HP 98331A (or B) Mass Storage ROM (set of 2 ROMs)
HP 98332A I/O ROM (set of 4 ROMs)
HP 98337A Plotter ROM
HP 98338A Assembly Execution ROM (1)
HP 98339A Assembly Development ROM (set of 2)
HP ????? Advanced Programming ROM

Price (1979) 9835A = $ 9,900
9835S = $ 8,700
(1981) 9835A = $10,400
9835B = $ 8,700

Size and Weight: Base 14 x 19 x ?? inches 25 pounds
Monitor ????????????inches 23 pounds

HP 9845

AKA System 45. HP called the HP 9845 the flagship of the 9800 series. That's an appropriate term considering the size and weight of one! The 9845 A was introduced in the April 1978 issue of the HP Journal . Their development code name was QWERT". The development code name for the 9845B was "Galleon". "There are four QWERTs in Galleon, you know". I swear that's what HP said! I asked how they came up with a name like QWERT and was told " My understanding is that the 9825 was called "keeper" which stood for key per function. This was the original design goal, however HPL turned into a pretty much full fledged programming language. Once a naming trend gets established, it tends to propagate. Apparently the 9845 team played on the keeper theme and adopted QWERT from the keyboard." The development code name for the color monitor used on the 9845C was "Odyssey". And finally the development code name for the 9845 option 200 was "Steamer". More on the option 200 later. The 9845s were available in a bewildering array of model numbers, options, packages, performance models and displays. The original model was the 9845A. It came standard with ~16k of read/write memory and one tape drive. In 1979 HP added the 9845S. The "S" model had 64k of read/write memory, two tape drives, a built in full page printer and a graphics capability. Both were replaced by the 9845B and 9845T 1980. The 9845C was introduced later the same year in the December 1980 issue of the HP Journal . The "A" and "B" models could only display alpha text in twenty-four 80 character lines. The major change in the "S" and "T" model were that they had graphics capability with a 560 x 455 dot matrix screen. The "T" model also came standard with more memory (186k) , the optional full page printer and second tape drive. The reader should be aware that most 9845s are only marked "B" even though they may have the graphics capability. In addition, I have never found a 9845 that had the installed options or memory listed on it anywhere. The 9845C models had a color monitor with a 13 inch CRT that was capable of displaying 4,913 colors, vector writing and also had an interactive light pen. The light pen was made optional in 1983. All "C" models had the graphics capability. In 1983, HP also added a new high performance bit slice CPU as option 200. (All 2XX options include the new CPU.) The 9845s actually use two nearly identical CPUs. One was called the LPU (Language Processing Unit) and the other called the PPU (Peripheral Processing Unit). The LPU handles the BASIC interpreter and the PPU handles all of the system I/O. All of the HPL and BASIC language machines used interpreters and HP found that in most programs the machines spent 80% of their time in the interpreter. Therefore HP rewrote most of the BASIC language interpreter in microcode. I've been told that the microcode was 2K words deep and about 56 bits wide. HP also replaced the LPU with a bit slice processor. The bit sliced processor was composed of a single AMD2910 microsequencer and four AMD2901 four bit wide "RALU" slices. There was also a set of specialized BCD adders to handle the BCD arithmetic. Here is a description of the enhanced processor from one of the guys at HP that worked on it: "The option 200 processor was built completely with off the shelf circuits. A standard processor is a single board with a heatsink that looks like a motorcycle head. In fact the guy that designed it referred to it as exactly that. The option 200 processor fits in the same slot, but is actually a module composed of three primary PC boards, with an interconnect board on top. Since the base board in the bottom of the machine was called the motherboard, we naturally referred to the interconnect board as the father board." The new faster LPU coupled with the up to 1.6 megabytes of memory that was available in the 9845s made them very capable machines. They were widely used for CAD systems, micro-processor development systems, data base query systems. Unfortunately they were dropped from the HP catalog after 1984 in favor of HP's new 9000 500 series computers. That's not surprising however considering that the list price on a high performance color 9845C was $39,000 without any additional options, peripherals or software! However, at one time it was the leading revenue product for HP.

The 9845s were a wonder of micro-electronics. A fully optioned 9845A included 36 NMOS Large Scale Integration ICs, 19 Medium Scale Integration ICs and 75 NMOS ROM ICs. And the "A" was the bottom of the line 9845! All of the special ICs were custom designed and built by HP. The 9845C was much more complex. The color monitor alone contained four power supplies supplying 9 different voltages! The 9845s were third generation machines and featured all of advances of the 9825s and 9835s included the same live keyboard, high speed tape drive, an extended number range and all of the interfacing capability of the 9835s such as buffered I/O, DMA, fast read/write, 15 levels of priority interrupts and built in I/O drivers. A second tape drive and a built in full page thermal printer were optional. The 9845s still had the three I/O slots in the rear of the case but HP again changed the design of the option ROMs. This time they built slide out ROM drawers into both sides of the machine. They also changed the shape and size of the ROMs. They were now small printed circuit boards mounted in long plastic cases that plugged into sockets in the ROM drawers. Each drawer could hold eight ROMs. Many of the ROMs had to go into a specific drawer and slot. Therefore the left hand drawer was color coded green and the right hand drawer was color coded black and the slots were identified with symbols. The ROMs that had to go into a specific drawer or slot were color coded and marked with matching symbols. This brings up another tidbit, the 9845A housed ALL of its ROMs in the ROM drawers. However due to a manufacturing supply problem, the system ROMs were moved out of the drawers and inside the machine for the 9845B and subsequent machines.

Like the 9835s ,the 9845s could be programmed in BASIC or Assembly Language. However the BASIC was even more powerful than that used in the 9835s and was so well optimized that many routines were faster in BASIC than they were in assembly.

misc. The standard monochrome monitor is model number 98750A. The color graphics monitor is model number 98770A. There was also a monochrome Enhanced Graphics monitor with model number 98780A that included it's own CPU and a hardware vector generator.

9845 options
all 1xx options = standard LPU
all 2xx options = high performance LPU

Option 150 = ????
Option 250 = high performance LPU and ????
Option 190 = HP 98430A Data Base Management System ROM
Option 290 = high performance LPU and HP 98430A Data Base Management System ROM
Option 175 = standard LPU and data communications package
Option 275 = high performance LPU and data communications package
Option 280 = high performance LPU and HP's IMAGE database management package

Option (100 or 200) and 204 = 192k of read/write memory
Option (100 or 200) and 205 = 312k of read/write memory
Option (100 or 200) and 206 = 512k of read/write memory

Option (150, 190, 250 or 290) = 192k of read/write memory
Option (150, 190, 250 or 290) and 215 = 312k of read/write memory
Option (150, 190, 250 or 290) and 216 = 512k of read/write memory

Option (175, 275, 280) = 512k of read/write memory
Option (175, 275, 280) and 207 = 1,088k of read/write memory
Option (175, 275, 280) and 208 = 1,664k of read/write memory

Option 311 = HP 98411B Graphics ROM
Option 312 = HP 98412A I/O ROM
Option 313 = HP 98413C Mass Storage ROM
Option 314 = HP 98414A Advanced Programming ROM
Option 438 = HP 98438A Assembly Execution ROM
Option 439 = HP 98439A Assembly Execution and Development ROM

9845 ROMs
HP 98411B Graphics ROM
HP 98412A I/O ROM (set of 2 ROMs)
HP 98413C Mass Storage ROM
HP 98417A Basic Data Comm ROM
HP 98414A Advanced Programming ROM
HP 98415A Structured Programming ROM
HP 98417A Basic DataComm ROM
HP 98418A Bisync DataComm ROM
HP 98438A Assembly Execution ROM
HP 98439A Assembly Execution and Development ROM
HP 98430A Data Base Management System ROM

Price (1979) 9845A = $11,000
9845S = $20,000
(1981) 9845B = $14,000
9845T = $23,500
9845C = $39,500
(1983) 9845B with option 175 = $24,000
9845B with option 275 or 280 = $28,000
9845C with option 275 or 280 = $39,000

Size and Weight: Base (w,d,h) 27 x 19 x 10 inches 45 pounds
HP 98750A Monochrome monitor 13 x 13 x 10 inches 23 pounds
HP98770A, Color CRT 18 x 17x 15 inches. est > 50 pounds

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.

AND finally here I am still hard at work!

This page was created by Joe Rigdon, Oviedo, Florida in the interest of preserving old calculator and Computer technology and history , even if it is an IBM. All original material is copyright 1997 by Joe Rigdon, all rights reserved.