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 | |
Overview
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.
HP 48SX
| Predecessor | HP 48SX |
|---|---|
| Successor | HP 48G+ |
| CPU | |
| Processor | Yorke (4MHz Saturn) |
| Programming | |
| Other | |
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 IR communications, 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. ROM card contents are accessed using the LIBRARY function.
HP 48S
| Predecessor | HP 48S |
|---|---|
| Successor | HP 48G+ |
| CPU | |
| Processor | Yorke (4MHz Saturn) |
| Programming | |
| Other | |
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
| Predecessor | HP 48G, HP 48GX |
|---|---|
| Successor | HP 49G |
| CPU | |
| Processor | Yorke (4MHz Saturn) |
| Programming | |
| Other | |
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.