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Following the success of the IBM PC business computer three years earlier, IBM attempted to capture the home market as well, with the IBM PCjr.
The PCjr was based on the same technology as the PC, and was compatible enough to run most of the software applications written for the PC.
Everyone had predicted it to be a huge success, until they actually used one. Hardware incompatibility issues and its relatively high price doomed it to failure. The wireless keyboard was terrible, with its uncomfortable keys and troublesome cordless infrared connection.
Additionally, cost-saving techniques used in the design limited the expansion, memory and speed of the system. For instance, with no DMA (direct memory access) capability, the keyboard is disabled when accessing the floppy drive. Even worse, the serial port will drop data when the floppy drive is in use - don't try to download data straight to the floppy, or you will lose it.
The expansion and interface ports on the back of the PCjr are all non-standard - an attempt to either simplify, or control access.
Certain options can be installed as a "sidecar" - an additional module that attaches to the right side of the PCjr. These include a parallel port or additional memory.
The PCjr was based on the same technology as the PC, and was compatible enough to run most of the software applications written for the PC.
Everyone had predicted it to be a huge success, until they actually used one. Hardware incompatibility issues and its relatively high price doomed it to failure. The wireless keyboard was terrible, with its uncomfortable keys and troublesome cordless infrared connection.
Additionally, cost-saving techniques used in the design limited the expansion, memory and speed of the system. For instance, with no DMA (direct memory access) capability, the keyboard is disabled when accessing the floppy drive. Even worse, the serial port will drop data when the floppy drive is in use - don't try to download data straight to the floppy, or you will lose it.
The expansion and interface ports on the back of the PCjr are all non-standard - an attempt to either simplify, or control access.
Certain options can be installed as a "sidecar" - an additional module that attaches to the right side of the PCjr. These include a parallel port or additional memory.