1100/40

The UNIVAC 1110 was the fourth member of the 1100 series, introduced in 1972.

The UNIVAC 1110 had enhanced multiprocessing support: sixteen-way memory access allowed up to six CAUs (Command Arithmetic Unit, the new name for CPU and so called because the CAU no longer had any I/O capability) and four IOAUs (Input Output Access Units, the name for separate units which performed the I/O channel programs). The 1110 CAU expanded the memory address range from the 18-bits (1108 and 1106) to 24-bits, allowing for up to 16 million words of addressable memory. The core memory used on the 1108/1106 systems was replaced with faster plated wire memory. Each memory cabinet contained eight independent 8K plated wire memory modules, or 64K for the entire cabinet. As with the 1108/1106, there was a maximum of four 64K cabinets per system. The 1110 also had 'Extended Memory' cabinets accessible in a 'daisy chain' arrangement to augment main storage. It was possible to utilize the 1108 64K core memory cabinets as Extended Storage, but in most systems utilized, the larger, less expensive 131K memory cabinets from the 1106 system. Up to eight Extended Memory cabinets were allowed, for a maximum of one million words of Extended Storage. An ESC (Extended Storage Controller) was required for each pair of memory cabinets to provide the physical connection, and address translation, from the 1110 CAUs and IOAU(s).

The minimum configuration for a 1110 system was two CAUs and one IOAU. The largest configuration, 6x4 was only used by NASA. The 1110 CAU was the first pipelined processor to be designed by UNIVAC. The CAU could have as many as four instructions in various stages of execution at any given instant. The IOAU was completely separate, both physically and logically from the CAU, and had its own access path to the various Main and Extended Memory Modules. This allowed I/O operations to be independent from the compute operations, no longer "stealing" memory cycles from CAU(s). The IOAU included 8 (optionally 16 or 24) 1108/1106 compatible 36-bit Word Channels, and also included the Hardware Maintenance Panel. Pictures/illustrations of a 1110 system typical showed the IOAU Maintenance Panel, as the CAU cabinet had no indicator lights. The IOAU Maintenance Panel could display the various CAU registers from one or two associated CAU(s). The 1110 CAU also introduced an extension to the instruction set of 'Byte Instructions'.[12] The major components of the 1110 system, the CAU, IOAU and Main Memory cabinets were designed using the same 55-pin high density card connectors, and machine wire wrapped backplane(s) as the 1108/1106. The discrete component logic used by the older systems was replaced by transistor–transistor logic (TTL) integrated circuits (see Note, below). The CAU was an extremely complex unit, utilizing over 1000 cards.

When Sperry Rand replaced the plated wire memory with semiconductor memory, the same machine was released as the UNIVAC 1100/40. In this new naming convention, the final digit represented the number of CPUs in the system. The 1100/40 utilized a new Main Memory cabinet, replacing the 8K plated wire memory modules with 16K static RAM modules (based on 1024x1-bit static RAM chips), for a total of 131K per cabinet. This allowed expansion of the Main Memory to a maximum of 524K. As with the 1110, the 1100/40 CAU had four base and limit registers, so a program could access four 64k banks. New instructions were added to allow a program to change the contents of the banks, rather than the banks being fixed when the program was prepared

Sperry Rand sold a total of 290 processors in 1110 systems.

Source: Wikipedia


This is a barebones 1100/40 emulator that appears to have been written by David William Nixon of Queen City Software, neither of which have I been able to track down. There is no assembler or other supporting software. The emulator runs under MS/DOS and the only way I have been able to get it to work is to run it under DOSBox, which is an MS/DOS emulator. So, to see an 1100/40 in action you will need to install DOSBox. Then you will need to download the emulator here. Unzip the archive to a folder on your hard drive. To run the emulator:

  • Start DOSBox.

  • In the DOSBox window issue a mount command to mount the 1100/40 emulator folder. For example, mount c: c:\univac21.

  • Make c: (or whatever drive letter you chose above) your current drive.

  • Start the 1100/40 by entering univac uniflash

  • Press F9 to start the 1100/40 running and watch the blinking lights. Until someone reverse engineers the .ABS file format and writes an assembler that is about all you can do with this emulator.