• p857_D3B_4311

Philips P857


Dimensions:48 x 22 x 55cm
Maximum memory size:128KW = 256KB
Maximum number of CPUs:1
uses architecture:P800
can contain:Philips CPB
System class:Minicomputer
  • p857_D3B_4315
  • p857_E3B_4313
  • rck_D3B_4308
  • rck_D3B_4321
  • rck_D3B_4325
  • tpe_D3B_4305

The Philips P857 was part of the second generation of minicomputers in the P800 family. The first generation consisted of the P850, P855 and P860. The second generation consisted of the P852, Philips P856 and P857. The third and last generation consisted of the P851, P853, P854, P858 and Philips P859.

The P857 was the top of the line for the second generation. Equipped with a memory management unit, the P857 could handle up to 128 Kwords of memory. Optionally, a floating point processor could be added.

Philips P857


Contains:Philips CPB

Internal links

Acquired Philips P800 mini computer systems

Getting an X1215 cartridge disc drive online

Emulating an X1215 cartridge disc drive

Stepping and reading an X1215

Reading 32-year old data off an X1215 disk pack

List of X1215 disk packs

Philips P857 [R0314]


Contains:Philips CPB

My P857 enclusure is filled with the maximum of 10 cards. I don't have a floating point processor. The P857 is connected to the following peripherals:

  • Serial console
  • X1215 cartridge disk drive
  • X1215 emulator (PC + FPGA based)
  • P830-010 enclosure with 2 8" floppy drives
  • P833 enclosure with 3 cassette drives

The picture of the entire rack shows (from top to bottom): 2 8" floppy drives, 3 cassette drives, P857, X1215, control panel for emulated X1215, P859.

I have some paper tapes with test programs for the P857, and although I don't have a Philips paper tape reader to go with the machine, I hope to be able to adapt a Brown-Boveri paper tape reader I have for use with the P857.


2 MMU Memory management Unit
3 M128E 128Kword RAM
4 IOP First I/O Processor
5 MCU3 Serial port, paper tape reader and punch interface
6 MCU2 Card reader and line printer interface
7 CDD Cartridge Disk Drive controller
8 IOP Second I/O Processor
9 FM1B 8" Floppy Disk controller
10 AMA-8A 8-port serial multiplexer
CC K7S2 Cassette Drive controller (in cassette drive enclosure)