The HP 9810, 9820 and 9830 were all announced simultaneously by HP in the December 1972 HP Journal (picture). The 9810, 9820 and 9830 were all four bit machines and all of them used a serial bus internally.
The HP 9830 was introduced in the December 1972 HP Journal (picture). 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 (picture) 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 (picture) 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!
???? 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
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
(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
9830 calculator 25 x 18 x 6 inches 43 pounds
9866 printer 15 x 18 x 6 inches 42 pounds