The PDP -1 ( Programmed Data Processor 1 ) was the first minicomputer and was established in 1959 by the DEC (Digital Equipment Corporation ) was developed.
The term minicomputer appears inappropriate from today's perspective, since the PDP-1 as large as two refrigerators. This PDP has however, in contrast to the much larger IBM machines are powered and controlled by a single person. In addition, he was able to be used simultaneously by multiple people. Requests that you turned on the PDP were immediately processed and output - in contrast to larger computers, the batch ( batch ) operation ran, where you gave the programs as a hole card stack with the operator and get the results as an expression of the next day could. Announced was the PDP-1 in 1960, the first model was installed in December 1959.
PDP 1 has been implemented with discrete transistor circuits, instead of using the conventional time electron tubes. Integrated circuits have not yet been used.
- Controls on the device itself ( lever and numerous buttons)
- Paper tape
- Light pen
- Teletype ( Teletype ) and keyboard ( at the same time output device)
- Round oscilloscope, vector graphics, technically derived from a radar screen; 12 characters width. Title: CRT Type 30 or Type 31 (Ultra Precision)
- Teletype ( Teletype ) as a printer
- Tape, after the still widespread standard
The computer will M.E.S.S. of the emulators and SIMH supported. Likewise, there are numerous Spacewar! Simulations.
Was programmed the computer in assembly language or in LISP. The memory was, in contrast to today's computers, not octet-wise, but in 18-bit addressing big words. The main memory consisted in the basic version from 4096 that words, which corresponds to 9216 octets.
There are a few basic commands. Most of the other related to the output devices.
Basic commands with the appropriate code
- ADD Y ( 40) ADD C (Y) to C ( AC)
- AND Y ( 02) logical AND C (Y) with C ( AC)
- CAL Y ( 16) JDA 100
- DAC Y ( 24) Depositphotos C in Y
- DAP Y ( 26) Deposit address part AC in Y
- DIO Y ( 32) Depositphotos C ( IO) in Y
- DIP Y ( 30) Deposits contents AC in Y
- DIV Y ( 56) Divide
- DZM Y ( 34) Deposit Zero in Y
- IDX Y ( 44 ) Index ( add one )
- IOR Y ( 04) Inclusive OR
- IOT Y ( 72) In -output transfer ( many commands following 2 Words required)
- ISP Y ( 46 ) Index and Skip
- JDA Y ( 17) equals DAC Y and Y 1 JSP
- JMP Y (60 ) next instruction from Y
- JSP Y ( 62) jump to Y, save program counter in AC
- LAC Y (20 ) load with AC C (Y)
- LAW N ( 70 ) load AC with numer N
- LAW- N ( 71 ) load AC with- N
- LIO Y (22 ) load IO with C (Y)
- MUL Y ( 54) Multiply
- OPR (76 ) Operate ( 9 commands, such as 760000 NOP)
- SAD Y ( 50) Skip next instruction if C ( AC) <> C (Y)
- SAS Y ( 52) Skip next instruction if C ( AC) = C (Y)
- SFT (66 ) shift, for example, 661 AC Rotate left, 676 right Shift IO
- SKP (64 ) Skip, eg 640200 Skip on AC plus
- SUB Y ( 42) subtract C (Y) from C ( AC)
- XCT Y ( 10) execute instructions in Y
- XOR Y ( 06), exclusive OR C (Y) with C ( AC)
Some examples of other major commands
- RPA ( 720001 ) read perforated tape alphanumeric
- RPB ( 720002 ) read perforated tape binary
- TYO ( 720003 ) type Out
- TYI ( 720004 ) type in
- DPY ( 720 007 ) display one point (CRT type 30 )
- PAC ( 720 043 ) punch a card ( previously: LAG load a group)
Predecessor was the TX- 0 (1955/1956), the first computer with transistors. In his text -based games already running, such as Tic -Tac -Toe.
The second model of the PDP -1 was famous because it as a gift went to the Massachusetts Institute of Technology ( MIT), Cambridge, where the famous game Spacewar by Steve Russell and other students has been developed.
- PDP -7
- PDP -8 / 8e / 8i
- PDP 10 / 10b / 10c / 10 Mk.III