.sh "VAX 11/780 PACKAGES" For a system with more growth possibilities than an 11/750, faster processing, and higher i/o bandwidth, we recommend starting with a small 11/780. Our goal here is to start with a system capable of supporting 8-16 timesharing users and expanding the system to be capable of supporting roughly 24 users. We also consider a large expansion of this system, to a system that might support 32 to 40 terminal users to the exhaustion of available CPU cycles.* .FS * Using systems similar to the largest shown here, in an environment consisting of small student programming some sites have reported running up to 70 interactive users; CPU cycles are the critical resource with this many users. .FE .SH Small system .LP For our small system we use 400 Megabytes of disk storage and a 125ips 6250bpi tape drive that will be capable of handling file backups if the system is eventually expanded. In our first expansion of this small system, we wish to add to the available space to a minimum of 800 Megabytes of disk storage, acquire at least two disk arms, and add additional terminal lines. In a large expansion of this system we include more terminals, an additional disk controller to get at least two separate disk channels, and an additional 800 Megabytes of storage for a total of 1600 Megabytes. .LP To build a small system from all DEC equipment, we would start with the RUA81/TU78 based system, the SV-AXECA-CA. This system includes 8 terminal lines, 4 Megabytes of memory, a 456 Megabyte disk drive and a 125ips 6250bpi tape. The system is equipped with two UNIBUS adaptors so that the UDA50 does not contend with other UNIBUS devices. To this we would add a floating point accelerator. .LP On the mixed vendor system we would substitute a Fujitsu Eagle 404 Mbyte disk drive on an Emulex SC780 SBI interfaced controller and an Aviv/Telex 6250 tape subsystem. .DS .TS box; cb s s l l l l l l. Small 780 System _ DEC System Mixed Vendor System _ CPU 11/780 11/780 from Broker or Integrator \^ \^ with .25 Mbyte DEC Memory and \^ \^ UNIBUS Adaptor Included Memory 4 Mbyte DEC 4 Mbyte National/Trendata/Mostek Disk System UDA50 Unibus Controller Emulex SC780 RH780 Emulator \^ RA81 456 Mbyte Drive Fujitsu 404 Mbyte Drive \^ on own UBA Tape System TEU78 125ips 6250 ips Aviv Controller \^ Tape Subsystem Telex Drive/Formatter Serial Lines DZ-11A Able/Emulex ``DH'' Other DEC Floating Pt. Acc. DEC Floating Pt. Acc. .TE .DE .SH Medium system .LP To expand this basic system to support more users and get additional disk space, we would add additional lines and disk storage. .DS .TS box; cb s s l l l l l l. Augmenting the Small 780 to a ``Medium'' System _ DEC System Mixed Vendor System _ Additional Disk RA81 456 Mbyte Drive Fujitsu 404 Mbyte Drive More Serial Lines DZ-11E Able/Emulex ``DH'' .TE .DE .SH Large system .LP To form a system with the emphasis on handling of data-intensive applications, and to emphasize total growth of the system, we would add a second disk channel and interleave memory to increase i/o throughput and reduce average CPU memory access as much as possible. In both the DEC and mixed vendor systems a CPU extension cabinet would be required in addition to another DEC memory controller. We would fill out the second memory system to 4 Megabytes. .LP For more disk throughput, we would add an REP07-AA 504MB disk drive on a MASSBUS controller to the basic DEC system. This disk provides a very high burst data throughput and could share the MASSBUS Adaptor of the Tape Unit with only minor performance loss while the tape unit was being used. .LP To accomplish the same ends with the mixed vendor system, we would simply add a second Emulex SC780 disk controller channel and at least one more Fujitsu Eagle 404 Mbyte disk drive. .DS .TS box; cb s s l l l l l l. Augmenting ``Medium'' 780 to ``Really Big'' System _ DEC System Mixed Vendor System _ Additional Disk RP07 (516 Mbyte) on Fujitsu Eagle (404 Mbyte) and Channel MASSBUS with tape sys. on another SC780 controller Second Memory DEC DEC Controller \^ \^ and Cabinet \^ \^ Additional Memory DEC Trendata/National Mostek More Serial Lines DZ-11E Able/Emulex ``DH'' .TE .DE