one monochrome). The 530 was a rackmount version of the Series 500, could only run HP-UX, and used a serial interface console. The 540 was a 530 mounted inside a cabinet, similar to the disk drives offered then and included a serial multiplexer (MUX). Later models of the Series 500s were the 550 and 560, which had a completely different chassis and could be connected to graphics processors. The processors in the original Series 500s ran at 20 MHz, and could reach a benchmark speed of 1 million instructions per second (MIPS), equivalent to a VAX-11/780, then a common benchmark standard. They could be networked together and with 200 and 300 series using the Shared Resource Manager (SRM). Because of their performance, the US government placed the 500 series on its export restricted list. The computers were only permitted to be sold in Western Europe, Canada, Australia, and New Zealand, with any other country needing written approval. Series 700 The first workstations in the series, the Model 720, Model 730 and Model 750 systems were introduced on 26 March 1991 and were code-named "Snakes". The models used the PA-7000 microprocessor, with the Model 720 using a 50 MHz version and the Model 730 and Model 750 using a 66 MHz version. The PA-7000 is provided with 128 KB of instruction cache on the Model 720 and 730 and 256 KB on the Model 750. All models are provided with 256 KB of data cache. The Model 720 and Model 730 supported 16 to 64 MB of memory, while the Model 750 supported up to 192 MB. Onboard SCSI was provided by an NCR 53C700 SCSI controller. These systems could use both 2D and 3D graphics options, with 2D options being the greyscale GRX and the color CRX. 3D options were the Personal VRX and the Turbo GRX. In early January 1992, HP introduced the Model 705, code-named "Bushmaster Snake", and the Model 710, code-named "Bushmaster Junior". Both systems are low-end diskless workstations, with the Model 705 using a 32 MHz PA-7000 and the Model 710 using a 50 MHz version. At introduction, the Model 705 was priced at under US$5,000, and the Model 710 under US$10,000. The first Series 700 workstations were superseded by the Model 715/33, 715/50, 725/50 low-end workstations and the Model 735/99, 735/125, 755/99 and 755/125 high-end workstations on 10 November 1992. The existing Model 715 and