MCM6670P character generator (128 × 7 × 5) pinout
DIP-18. Model I alphanumeric character generator: 5 × 7 dot rows for the 64 or 128 character codes.
Horizontal-scan character generator: a 7-bit character code on A0-A6 and a 3-bit row select on RS1-RS3 give five dots on D0-D4. On the Model I the latched codes from Z28 drive pins 1 to 7 and the line counter L1, L2, L4 drives the row select. A dead or wrong part gives the right screen layout with garbage shapes in every character; graphics blocks (from Z8) still look right.
Open the interactive MCM6670 pinoutPins
| Pin | Name | Type | Signal |
|---|---|---|---|
| 1 | A6 | addr | Character code bit 6, the "sneaky" seventh bit, from latch Z27 (bit in on pin 13). |
| 2 | A5 | addr | Character code bit 5, from the video data latch Z28. |
| 3 | A4 | addr | Character code bit 4, from the video data latch Z28. |
| 4 | A3 | addr | Character code bit 3, from the video data latch Z28. |
| 5 | A2 | addr | Character code bit 2, from the video data latch Z28. |
| 6 | A1 | addr | Character code bit 1, from the video data latch Z28. |
| 7 | A0 | addr | Character code bit 0, from the video data latch Z28. |
| 8 | RS3 | addr | Row select bit 3 (most significant). Picks which of the 7 dot rows is output. |
| 9 | Gnd | ground | Ground. |
| 10 | RS2 | addr | Row select bit 2. |
| 11 | RS1 | addr | Row select bit 1 (least significant). |
| 12 | D0 | video | Dot output 0 to the shift register. |
| 13 | D1 | video | Dot output 1 to the shift register. |
| 14 | D2 | video | Dot output 2 to the shift register. |
| 15 | D3 | video | Dot output 3 to the shift register. |
| 16 | D4 | video | Dot output 4 to the shift register. |
| 17 | /CS | ctrl | Chip select, active LOW. |
| 18 | Vcc | power | +5 V ±10 %. |
Fitted in
- TRS-80 Model I Z29