How many registers should the PDP-11 have?

How many registers should the PDP-11 have?

In other words, the byte ordering was little endian. The top 4096 words in the memory space (from 177777 downwards) were reserved for the system, giving 28,672 words for programming. The PDP-11 had 8 16-bit registers that could be used by the programmer.

How many bits are in a memory location?

8 bits
One memory location stores 1 byte (8 bits). The basic storage unit for memory is 1 byte. If you need to store 4 bytes, and place the first byte at 0001, the last byte will be at 0004. That’s one byte at each of 0001, 0002, 0003, and 0004.

How much RAM did the PDP-11 have?

4 MB
PDP-11/70 – 1975. The 11/45 architecture expanded to allow 4 MB of physical memory segregated onto a private memory bus, 2 kB of cache memory, and much faster I/O devices connected via the Massbus.

How much was PDP-11?

The venerable PDP-11 is still spry to this day, powering a GE nuclear power-plant robotic applications — and will do so until 2050! That’s right! The first model of PDP-11, (priced 20000 USD), named PDP-11/20, was shipped in the spring of 1970.

Is PDP-11 byte addressable?

The PDP-11 is a byte addressed machine but it has a 16 bit data bus. If you issue a word read to address 100, it will return you the two bytes at 100 and 101. The PDP-11 is little endian so the byte at 100 is the low byte.

What does PDP-11 stand for?

Programmed Data Processor-11
PDP-11 (Programmed Data Processor-11) is one of the most famous computers in computing history, one of a series manufactured by Digital Equipment Corporation ( DEC ) from the early 1960s through the mid-1990s.

How do I find my memory location?

How to Calculate a Memory Address

1. Take your 16-bit segment and offset addresses and break them into pairs.
2. Add the two 20-bit addresses together in binary form to get the hexadecimal address of the memory.

What does PDP 11 stand for?

Who created the PDP 11?

Digital Equipment Corporation
PDP-11/Manufacturers

Are PDP-11 still in use?

The venerable PDP-11 minicomputer is still spry to this day, powering GE nuclear power-plant robots – and will do so for another 37 years. “The role supports the nuclear industry who has committed to continue the use of PDP-11 until 2050”, she writes.

How many physical 4 byte words are there on a PDP 11?

The PDP-11/70 uses 22 bits for addressing physical memory. This represents a total of 222 (over 4 million) byte locations.

What are the 4 bits on the PDP-11?

There is also a Processor Status Register/Word (PSW) which indicates the 4 condition code bits (N, Z, V, C), the Trace Trap bit, processor interrupt priority, and 4 bits for current and previous operating modes. Addressing on the -11 is linear from memory address 0 through 177777.

What is address range of PDP-11 emulator?

Addressing on the -11 is linear from memory address 0 through 177777. Memory management allows access to physical memory with addresses of up to 22 bits (17777777). All I/O devices, registers etc are addressed as if they were part of memory. These live in the 4KW of reserved memory space at the top of the addressing range.

What kind of memory does the PDP 11 / 34 have?

PDP-11/34 and PDP-11/04 – Cost-reduced follow-on products to the 11/35 and 11/05; the PDP-11/34 concept was created by Bob Armstrong. The 11/34 supports up to 256 kB of Unibus memory. The PDP-11/34a supports a fast floating-point option, and the 11/34c supported a cache memory option.

How many PDP-11 minicomputers have been sold?

In total, around 600,000 PDP-11s of all models were sold, making it one of DEC’s most successful product lines. The PDP-11 is considered by some experts to be the most popular minicomputer.