Introduced around 1983-84, the TPA-11/440 was called a "megamini". It was an enhancement to the DEC PDP-11 architecture. Some of the performance improvements came from the greatly extended instruction set: it had 46 new standard floating-point instructions, and CIS/EIS as an option.
It also had a special 32-bit system bus, called the x-bus. Unfortunately not many options used this new bus, most of the peripherals and other devices were using the UBUS (the KFKI-equivalent of the UNIBUS), so there wasn't really much on the x-bus besides the four-board CPU and the maximal 4MB memory (and of course the xbus-ubus converter). The performance of the machine measured around 0.5-0.6 VUPs (VAX unit of performance).
The machine had a Z80-based front-end processor, which was a new version of the TPA-1148 console. It could run tests and bootstraps from PROMs.
Typical mass storage devices for the 11/440 were the bulgarian CM5300 (5200? I might be wrong about this) tape drives, CDC96xx hard disk drives (80 MB on removable platters); Kennedy9600 tape drives and Fujitsu SMD drives later.
Many 11/440's are still in use today in Hungary, most of them run different versions of RSX-11M+ and RT-11 (for example there is an altered version of RT-11 called MORT).
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