970705  5580-Y0C Arrived 

 Big Fat Mama was delivered to my apartment room.  After I unpacked the container and exposed the machine on the floor,  I immediately  named it " Grandma" ( grand mother ).  It was an analogous to PS/2 9595 Type-1 K with 1S1P planar.  Grandma came with 2FDD, SCSI 32/A with old micro code set, 320MB SCSI HD and 8MB( 4x 2MB SIMMs) memory.  256KB cache daughter card was sit on the complex.  It was really impressive machine and  it was The computer ( well , I didn't  know about 9595A nor Server 500 back then ).  I loaded SCSI CD-ROM ( no-bezel ), DX4ODPR-100.  Memory count was really slow with the stock complex. 

Later on I got 8 sticks of  8MB parity SIMMs.  To say the truce I did not do any real job with the box for a while but I learned a lot about MCA, IML, SIMM for PS/55, CPUs and interposers and so on.

   Grandma accelerated MAD level .
 

   About 5580-Y
   Released ;   OCT. 1990
   Price       ;   No idea. May be you could buy a new car
   Processor complex ;  Type-1 K'ish 33MHz complex. 
   Planar     ;  1S1P ( x1 serial,  x1 parallel port ) type
   Y0x model does not have a translucent plastic lid covering main power SW.
   Y1x model does have the lid to prevent unintended system shut down caused by pushing the
   SW instead of FDD eject button ( maybe...).  Have you ever pushed the main power SW and
   kept pressing it until you finished whole job with floppies?  I DID it twice or more when I 
   installed PC DOCJ7.0?V ( Japanese bilingual PC DOS7.0 consisted with 9 floppies ).

   My "Grandma" has 2x FDD. I think 1FDD is enough as far as I use PC DOS higher than Ver.
   5.0.  Copying files A to B will take a time if there are 2 FDDs physically. 

   Upgrade
   If your system have DX2/66 upgrade type-A complex then yours is the second best. 
   The ultimate upgrade for 5580 is to use Type-4 Y complex with P-90.