PCjs Machines
Home of the original IBM PC emulator for browsers.
UCSD p-System IV.0 with Pascal
The UCSD p-System was one of three operating systems IBM offered for the original IBM PC, alongside PC DOS and CP/M-86. Developed at the University of California, San Diego, and licensed by SofTech Microsystems, the p-System was a portable operating system built around a pseudo-machine (p-machine) interpreter, so that programs compiled to p-code could run unchanged on any machine with a p-System interpreter.
IBM released UCSD p-System Version IV.0 in 1982 as part of its “Personal Computer Computer Language Series”, in two packages: one with the UCSD Pascal compiler, and one with a FORTRAN-77 compiler. Both packages shared the same five system diskettes (STARTUP, SYSTEM 2, UTILITY, SYSTEM 4, and EXTRAS), and differed only in the sixth diskette containing the compiler.
Two complete operating systems are included: one on the SYSTEM 2 diskette, and one on the SYSTEM 4 diskette. The numbers refer to the size of the floating-point format each system uses (2-word or 4-word reals), and the Pascal diskette contains a compiler for each (SYSTEM.COMPILER and PASCAL4.COMPILE).
The machine below boots the STARTUP diskette, with the PASCAL diskette in drive B. The STARTUP diskette automatically runs two short demo programs: a maze generator, followed by a “ROW ROW YOUR BOAT” data entry demo. Press Q to quit each demo. The main p-System command line then appears at the top of the screen:
Command: E(dit, R(un, F(ile, C(omp, L(ink, X(ecute, A(ssem,? [IV.03 B3n]
Type ? to see the rest of the available commands.
The p-System uses its own disk format, not the FAT format used by PC DOS, so these diskettes cannot be read by DOS, and the usual PCjs directory listings cannot be generated for them. The listings below were produced by decoding the p-System directory stored on each diskette, in the style of the p-System Filer’s L(ist command.
[PCjs Machine "ucsd-pascal-iv"]
Waiting for machine "ucsd-pascal-iv" to load....
Directory of UCSD p-System IV.0 STARTUP (6936529)
STARTUP:
SYSTEM.PASCAL 121 9-Jan-82
SYSTEM.INTERP 27 9-Mar-82
SYSTEM.MISCINFO 1 27-Jul-81
SYSTEM.FILER 32 19-Jul-81
SYSTEM.EDITOR 49 19-Jul-81
SYSTEM.STARTUP 12 19-Jul-81
SYSTEM.SYNTAX 14 22-May-81
NAMEFILE 3 9-Jun-81
SCDEMO.CODE 3 19-Jul-81
COPYSCUNIT.CODE 4 19-Jul-81
UPDATE.CODE 4 9-Jan-82
COMPDEMO.TEXT 6 9-Jan-82
EDITDEMO.TEXT 4 5-Jun-81
UPDATE.TEXT 8 9-Jan-82
14/14 files<listed/in-dir>, 288 blocks used, 22 unused, 22 in largest
Directory of UCSD p-System IV.0 SYSTEM 2 (6936534)
Note that this copy of the SYSTEM 2 diskette is slightly newer than the copy included with the FORTRAN package: the SYSTEM.PASCAL, SYSTEM.INTERP, and SYSTEM.LIBRARY files are dated July 1982, matching the dates on the PASCAL diskette.
SYSTEM2:
SYSTEM.PASCAL 121 15-Jul-82
SYSTEM.MISCINFO 1 9-Jan-82
SYSTEM.INTERP 27 19-Jul-82
SYSTEM.FILER 32 19-Jul-81
SYSTEM.EDITOR 49 9-Jan-82
SYSTEM.STARTUP 2 29-Oct-81
SYSTEM.LOGO 4 29-Oct-81
SYSTEM.SYNTAX 14 22-May-81
SYSTEM.LIBRARY 35 15-Jul-82
SPOOLER.CODE 2 27-Jul-81
10/10 files<listed/in-dir>, 287 blocks used, 23 unused, 23 in largest
Directory of UCSD p-System IV.0 UTILITY (6936544)
UTILITY:
XREF.CODE 29 27-Jul-81
TAPE.CODE 5 27-Jul-81
CODEGEN.CODE 74 14-Jan-82
LIBRARY.CODE 13 27-Jul-81
PATCH.CODE 34 9-Jan-82
DECODE.CODE 28 27-Jul-81
SETUP.CODE 27 27-Jul-81
COPYDUPDIR.CODE 3 9-Jan-82
MARKDUPDIR.CODE 4 9-Jan-82
RECOVER.CODE 8 27-Jul-81
PRNCONFIG.CODE 4 27-Jul-81
TVADJUST.CODE 3 27-Jul-81
SETBAUD.CODE 2 19-Jul-81
DISKFORMAT.CODE 4 1-Mar-82
DISKSIZE.CODE 3 19-Jul-81
15/15 files<listed/in-dir>, 241 blocks used, 69 unused, 69 in largest
Directory of UCSD p-System IV.0 SYSTEM 4 (6936539)
SYSTEM4:
SYSTEM.PASCAL 123 9-Jan-82
SYSTEM.MISCINFO 1 9-Jan-82
SYSTEM.INTERP 28 9-Mar-82
SYSTEM.FILER 32 19-Jul-81
SYSTEM.EDITOR 49 19-Jul-81
SYSTEM.STARTUP 2 29-Oct-81
SYSTEM.LOGO 4 29-Oct-81
SYSTEM.SYNTAX 14 22-May-81
SYSTEM.LIBRARY 34 9-Jan-82
SPOOLER.CODE 2 27-Jul-81
10/10 files<listed/in-dir>, 289 blocks used, 21 unused, 21 in largest
Directory of UCSD p-System IV.0 EXTRAS (6936549)
EXTRAS:
SYSTEM.LINKER 26 19-Jul-81
SYSTEM.ASSMBLER 60 9-Jan-82
8086.OPCODES 5 22-May-81
8086.ERRORS 11 22-May-81
COMPRESS.CODE 10 9-Jan-82
GOTOXY.CODE 3 19-Jul-81
GOTOXY.TEXT 4 20-May-81
SPOOLOPS.CODE 7 19-Jul-81
COMMANDIO.CODE 10 19-Jul-81
KERNEL.CODE 65 7-Jan-82
SCREENOPS.CODE 13 19-Jul-81
8087.FOPS 3 22-May-81
INTERPX.2.CODE 23 21-Dec-82
INTERPX.4.CODE 24 21-Dec-82
RSP.CODE 6 29-Sep-81
BIOS.CODE 10 9-Mar-82
BIOS.S.CODE 10 9-Mar-82
TERTBOOT.CODE 7 29-Sep-81
RS232SET.CODE 7 20-Jan-82
19/19 files<listed/in-dir>, 304 blocks used, 6 unused, 6 in largest
Directory of UCSD p-System IV.0 PASCAL
PASCAL:
SYSTEM.COMPILER 102 13-Jul-82
PASCAL4.COMPILE 102 13-Jul-82
2/2 files<listed/in-dir>, 204 blocks used, 106 unused, 106 in largest