FIXED HEAD DISC/DRUM DIAGNOSTIC (24184 AND 24207)
  requires 8K, DMA, TTY and any Cupertino Division fixed head
  disc/drum

1. Load and configure TTY SIO Driver.
2. Load diagnostic: S.A. = 2; Sw Reg (0-5) = TTY SC, (6-11) = Disc/Drum SC;
   set bit 12* for 2114/2115; set bit 14 for DMA ch 7 (=0 for ch 6);
   PRESET, RUN, Hlt 77 @ P = 12066. (*Bit 12 not used on 24207)
3. S.A. = 100, Sw Reg for options: (recommend 000000).
   PRESET, RUN. (requires ~11 min)

   Bit    Function
   ---    --------
   0-1    spare
   2      Alter track table and/or pattern table
   3      Execute Operator designed test
   4      Enter device parameters (in START) and Protect tracks
   5      Shorten tests S3 & S5 and eliminate S2
   6      Restricts track selection and shortens S2 & S4
   7      Repeat last section
   8      Repeat last section ON ERROR 5 times before Reporting
   9      Halt after each section
   10     Suppress all non-error messages
   11     Suppress all messages
   12     Halt at end current pass
   13     Loop at end current pass
   13     Loop current operation
   14     Suppress program halts after each error
   15     Halt after current operation

TESTS:
   INIT   Initialization routine, S.A. = 2
   START  Prints preamble, gets tracks, and sectors and does Flag, Control,
          and Interrupt testing.
   S1     Short reads and writes
   S2     Checks bad tracks and marginal heads
   S3     Verifies data transfer from random locations
   S4     Fills device with check summed data for use in S5
   S5     Reads and checks track, sector and checksum
   S6     Operator designed program

STATUS
   Bit     Function
   ---     --------
   15      SECTOR FLAG logical 1 - sector is past this rotation
   14-13   Not used
   12-8    NEXT SECTOR ADDRESS
   7       DRUM READY FLAG logic 1 - ready
           logic 0 - not ready due to low drum speed, heads switch
           not at the IN position, certain drum circuits defective, drum
           memory not connected to computer, low line voltage, drum
           power supply defective.
   6       Not used
   5       SECTOR ADDRES COINCIDENCE FLAG logic 1 - coincidence has
           occurred since last STC instruction
   4       Not used
   3       ABORT FLAG logic 1 - bit 7 has been 0 since last STC
           indicating possible error (cleared by STC Data SC)
   2       WRITING ENABLED FLAG logic 0 - track protected
   1       PARITY ERROR FLAG logic 1 - read parity error has occurred
           (cleared by STC Data SC)
   0       DRUM BUSY FLAG logic 1 - read/write in progress

Switch up for protected tracks.
