HP 48
The HP 48 series is five RPL graphing calculators first introduced in 1990.
 | |
| Introduced | 1990 |
|---|---|
| Predecessor | HP 28S and HP 41C |
| Successor | HP 48GX |
| CPU | |
| Processor | Clarke (2MHz Saturn) |
| Programming | |
| Other | |
| Successor | HP 48G |
|---|---|
| CPU | |
| Processor | Clarke (2MHz Saturn) |
| Programming | |
| Other | |
| Predecessor | HP 48SX |
|---|---|
| Successor | HP 48G+ |
| CPU | |
| Processor | Yorke (4MHz Saturn) |
| Programming | |
| Other | |
| Predecessor | HP 48S |
|---|---|
| Successor | HP 48G+ |
| CPU | |
| Processor | Yorke (4MHz Saturn) |
| Programming | |
| Other | |
| Predecessor | HP 48G, HP 48GX |
|---|---|
| Successor | HP 49G |
| CPU | |
| Processor | Yorke (4MHz Saturn) |
| Programming | |
| Other | |
Overview[edit | edit source]
All models are based on the Saturn processor. The HP 48 has RS-232-compatible serial and bidirectional infrared, and the expandable ("X") models have two slots for a ROM or RAM expansion card. The screen is a traditional 131x64 twisted nematic LCD.
User RAM is 32 KB in the S, SX, and G models and 128 KB in the GX and G+ models.
Note due to the change from FOCAL to an ECMA94 character set, from this model onwards the corresponding printer is HP82240B which had ECMA94 support. Printing with HP82240A is also possible using the OLDPRT command for compatibility.
HP 48SX[edit | edit source]
The HP 48SX was the first model of the series, released in 1990. It expands on the features of the HP 28S, expanding upon the RPL system. It adds several new object types, a new powerful unit conversion system, a graphical equation editor (the first of its kind on a calculator) and matrix editor, more graphing options, serial and two-way IR communications which allowed peer-to-peer object transfers between two 48 series calculators, in addition to printing to HP 82240B, and a clock and alarm system. The model number comes from a combination of the HP 41 and the HP 28, as it bridges the best features of both systems.
It used a 2 MHz Saturn processor known as Clarke, and was shipped with 256 KB of ROM and 32 KB of RAM. The "X" which stood for "expandable" refers to the two memory slots behind the IR cover which allowed additional ROM or RAM cards to be inserted, labelled "Port 1" and "Port 2" from inside out. Both ports supports operation in either "merged" mode, as in using the additional RAM as part of the main RAM, or in "free" mode, treating the memory as independent storage areas. As a result the HP 48SX has the largest merged RAM in the series with two cards plugged in, at (32+128+128 =) 288KB. However, this represent only just over half of the internal memory address space of 512KB and is achieved at the expense of permanantely occupying two slots. ROM card contents are accessed using the LIBRARY function.
HP 48S[edit | edit source]
The HP 48S was introduced in 1991 as a lower-cost alternative to the 48SX. It is identical in every way to the 48SX except that it is missing the two expansion slots of the SX.
HP 48GX[edit | edit source]
The HP 48GX was introduced in 1993 and was designed to address some of the issues with the 48S series. For one, it has 128 KB of RAM built-in for user data. It also uses a 512 KB ROM with many new features, including the Equation Library (which was an expansion card for the 48S series), a new GUI interface, XModem serial transfers, and a new case design.
In contrast with the SX, the GX treated the two card slots differently. Port 1 (slot 1) can be operated in both "merged" and "free" mode, while the outter slot can only be operated in "free" mode. This effectively limited the merged memory of the GX to 256KB, but allowed additional ROM or RAM card to be used while at this capacity, which was considered a net gain. The 2nd slot can accept RAM cards up to 4MB in size, with the GX treating each 128KB region as one Port, thus the 2nd slot could be divided into Port 2 up to Port 33.
HP 48G[edit | edit source]
The HP 48G was introduced simultaneously with the GX, as a lower-cost option like the 48S. It had only 32 KB of internal user RAM and was not expandable.
HP 48G+[edit | edit source]
The HP 48G+ was introduced in 1993. It is identical to the 48G except for its user RAM, which is expanded to 128 KB like the GX. The 48G+ is different, however, in that it was designed by HP's Australian Calculator Operation (ACO) group, as a way for them to "try out" the process of producing a calculator before they designed the HP 49G.