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PGM [06-Nov-81]

 I recently received some advertising  literature and a user manual  for
 what looks like an exciting new  development called the PGM -  Personal
 Graphics Machine, manufactured by Superset, Inc., 10633 Roselle St, San
 Diego, CA 92121, Tel: (714) 452-8665.  It is a single-process  personal
 computer designed  for FORTRAN,  with a  48-bit word,  an  architecture
 which is influenced by the old CDC 3600 and Burroughs 6700 machines,  a
 file system reminiscent of  the Univac 1108 series,  and a 24-bit  word
 virtual address space (100 Mbytes).  What is more, the instruction  set
 is essentially  micro-coded FORTRAN,  with  an average  of 1.1  to  1.4
 instructions generated for  each FORTRAN statement.   It looks like  an
 excellent machine for debugging, with features like

 * a hardware  undefined-value  bit pattern  which  causes a  trap  when
   referenced,

 * a hardware stack for storing the last 64 instructions, or the last 64
   jumps, or the last 64 memory references,

 * hardware array bounds checking,

 * argument list length checking,

 * symbolic debugger available for all programs.

 The price for the  PGM, including a  29-Megabyte Winchester disk  drive
 and 48K words physical memory (expandable), is about $27K.  The  entire
 system sits in a box about the size of an apple crate, and runs FORTRAN
 programs from 3 to 5 times faster than a DEC VAX-11/780.