9900

16-bit Microprocessor

Family table

Model	Description	Package
TI990/9	Early multi-chip CPU for minicomputer systems, 1974
TI990/10	Multi-chip implementation for minicomputer systems, 1975
TI990/12	Multi-chip implementation, faster than 990/10
TMS9900	Single chip implementation, 1976, used in the TI-99/4(A) computer	DIP64-750mil
TMS9940	Microcontroller with 2KB ROM, 128B RAM, decrementer, CRU bus, 1979
TMS9980 TMS9981	8-bit databus versions of TMS9900	DIP40-600mil
TMS9985	TMS9940 with 8KB ROM, 256B RAM, and an 8-bit external bus, c. 1978 (never released)
TMS9989	Improved 9980, used in military hardware	DIP40-600mil
TMS9995	Improved TMS9985-like, no ROM. Used in the TI-99/2 & TI-99/8 prototypes, the Tomy Tutor and the Geneve computer	DIP40-600mil
TMS99105	Baseline member of the TMS99000 microprocessor family
TMS99110	TMS99000 family microprocessor with floating point instructions pre-programmed into the on-chip Macrostore ROM memory
TMS99120	TMS99000 family microprocessor with run-time support routines for the PASCAL high-level language pre-programmed into the on-chip Macrostore ROM memory (microprocessor was announced but may never have been commercially produced)

Pinout

          TMS9900
       SDIP64-750mil
         +---\/---+
     VBB | 1    64| *HOLD
     Vcc | 2    63| *MEMEN
    WAIT | 3    62| READY
   *LOAD | 4    61| *WE
   HOLDA | 5    60| CRUCLK
  *RESET | 6    59| Vcc
     IAQ | 7    58| NC
  PHASE1 | 8    57| NC
  PHASE2 | 9    56| D15
     A14 |10    55| D14
     A13 |11    54| D13
     A12 |12    53| D12
     A11 |13    52| D11
     A10 |14    51| D10
      A9 |15    50| D9
      A8 |16    49| D8
      A7 |17    48| D7
      A6 |18    47| D6
      A5 |19    46| D5
      A4 |20    45| D4
      A3 |21    44| D3
      A2 |22    43| D2
      A1 |23    42| D1
      A0 |24    41| D0
  PHASE4 |25    40| Vss
     Vss |26    39| NC
     Vdd |27    38| NC
  PHASE3 |28    37| NC
    DBIN |29    36| IC0
  CRUOUT |30    35| IC1
   CRUIN |31    34| IC2
 *INTREQ |32    33| IC3
         +--------+

            TMS9980
          DIP40-600mil
           +---\/---+
     *HOLD | 1    40| *MEMEN
     HOLDA | 2    39| READY
       IAQ | 3    38| *WE
A13/CRUOUT | 4    37| CRUCLK
       A12 | 5    36| Vdd
       A11 | 6    35| Vss
       A10 | 7    34| CKIN
        A9 | 8    33| D7
        A8 | 9    32| D6
        A7 |10    31| D5
        A6 |11    30| D4
        A5 |12    29| D3
        A4 |13    28| D2
        A3 |14    27| D1
        A2 |15    26| D0
        A1 |16    25| INT0
        A0 |17    24| INT1
      DBIN |18    23| INT2
     CRUIN |19    22| Ø3
       Vcc |20    21| Vbb
           +--------+

Frequency

9900
Set reader to FREQ, put black probe to GND, red probe to 8,9,25,28,60 to measure CPU clock

9980
Set reader to FREQ, put black probe to GND, red probe to 22,34,37 to measure CPU clock

External links

TMS9900 page on Wikipedia
9900 page on CPU-World
9980 page on CPU-World
9995 page on CPU-World

Files

• 
  TMS9980 Datasheet