HP-71B

The HP - 71B is a programmable in BASIC Calculator by Hewlett- Packard, which was produced from 1984 to 1989. He replaced the HP -75 and was smaller and lighter than this. Four expansion slots allowed the expansion of the memory or the use of ROM modules, including an emulator for the HP - 41, which reached about five times the speed of the original with full functionality.

Properties

The HP - 71B has a single-line LCD display of 22 characters, which could be used in a graphics mode with 8 × 132 pixels. The keys were preassigned often use commands, but could be defined by the user. The computer could be secured with a password and use only after entering the correct password. The lock could be by removing the batteries (four pieces AAA ) deal, but only under the deletion of all data in the memory of the computer.

The HP - 71B was the first computer that used the "Saturn " CPU whose development in the HP -28 and HP -48 was used later. Also, the first model he used floating point numbers according to the IEEE standard, instead of the previous models used in BCD representation. He had a real time clock, which could be used for time-controlled starting of programs. The memory included 64 KiB ROM and 17.5 KiB RAM; the total storage could be up to 512 KiB ( the CPU was 1 Mi nybbles address ) to expand. By the HP -75 acquired elongated magnetic card with a capacity of 2 × 650 bytes per card could use up, but popular were HP -IL devices such as tape playback 82161A and the floppy drive 9114A, which were also supplied from batteries and therefore in the same way were transportable. Both devices, magnetic card reader, such as HP -IL module, were extensions that were installed in two other shafts on the back of the computer. An optical wand was also taken over by HP -41 ( ' wall '), which enabled the reading of barcodes.

For use as a calculator, the HP - 71B had a special input mode, which more closely resembled AOS as the UPN used until then. The computer identified it as you type already evaluated partial results, but also had a correction after this operation to. The internal processing followed still UPN, the stack was used as usual.