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  1. This is the corrected schematic for the KAY256.LBR  256K ram modification
  2. for '83 series KayPro computers, Models II and IV. This one works fine!
  3. Also, you Turbo-Rom users may want to see the text file TURBO256.TXT.
  4.  
  5. Many thanks to Dr. Liddle and to all those who debugged this fine
  6. mod!
  7.  
  8.  
  9. Charles McHan
  10. AMY  <>  BBS
  11. MULTI-SYSTEM
  12. (904)725-7461
  13.  
  14.  
  15.  
  16. \_TABLE I\_
  17.  
  18.              Signal on                  Chip on
  19.              Board                      Kaypro II/IV
  20.  
  21.              REFRESH                    U48 pin 12
  22.              MUX                        U33 pin 1
  23.              A14                        U33 pin 11
  24.              A15                        U33 pin 10
  25.              RA7                        U20 pin 9
  26.              RA8                        U20 pin 1
  27.              PIO 1                      Pad E29
  28.              PIO 2                      Pad E28
  29.              PIO 3                      Pad E31
  30.  
  31. \_FIGURE 1\_
  32. \l0i
  33.                          +-----------------------------+
  34.                          |                             |
  35.                          |         +--------+          |
  36.                          |  +------|    7   |- 0v      |
  37.                          |  |     -|    4   |----------+
  38.                          |  |     -|    L   |-
  39.                          |  |     -|    S   |-
  40.                          |  |  0v -|    3   |-
  41.                          +--|------|    9   |- 0v
  42.                             | +5v -|    3  1|----------o----------< RFRSH
  43.                             |      +--------+          |
  44.                             |                          |
  45.                      33R    |      +--------+          |
  46.              RA7  <-- / /---|------|        |- 0v      |
  47.                             +------|    7   |-         |
  48.                          +---------|    4   |-         |
  49.                          |        -|    L   |-         |
  50.                          |        -|    S   |-         |
  51.                          |        -|    1   |-         |
  52.                          |     0v -|    5   |- 0v      |
  53.                          |    +5v -|    8  1|----------+
  54.                          |         +--------+
  55.                          |
  56.                          |         +--------+
  57.                          +---------|        |- 0v        33R
  58.              A14b  >------------o--|    7   |------------ / /--------> RA8
  59.                                  \_|    4   |-----------------o------< PIO 2
  60.              PIO 1 >---------------|    L   |-< +5v >-/\/\/\_/ 4.7k
  61.                                0v -|    S   |-----------------o------< PIO 3
  62.              A15b  >---------------|    1   |-< +5v >-/\/\/\_/ 4.7k
  63.                                0v -|    5   |------------------------< MUX
  64.                               +5v -|    3  1|- 0v
  65.                                    +--------+
  66.