facit 4070 punch...

When I remove the baseplate, the first board visible does have some stuff on it, but certainly not a uart. This first board is almost (within 1/2 inch) as long as the board underneath it. This first board is virtually empty, except there was one row of 13 small transistors top to bottom, then a row of approximately 3 resistors and 1 diode for each transistor. Then there's a fair amount of traces taking the signals to the edge connector. It would appear that the sole purpose of the back half of this board is to bring two test points to the rear of the unit (6v and gnd).

The board underneath this appears to be the main logic board you referred to, as there are a number of power transistors on the board. As a point of reference, there are also a set of hardwired jumpers, labeled 1 through 8 on the board too. Next to this is a set of small transistors marked off as 1 through 9. Then there is a metal plate (3 screws remove the top half of it) revealing a final small PCA, obviously power related (theres a few 7 watt resistors, and what appears to be some yellow coils).

Here's the jumper board info - it's very simple. First find pin A1 on the option card connector. This is linked to pin 1 on the DB25, so an ohmeter will find it. The pins on that side of the connector are A1-A22, those on the other side are B1-B22 The jumper board links : A1-B1 A2-B2 A3-B3 A4-B4 A5-B5 A6-B6 A7-B7 A8-B8 A9-B9 A10-B10 A11-B11 A12-B12 A13-B13 (maybe, the manual is unclear here, but unless you need the timing pulse output it doesn't matter) That's it. 12 or 13 through-board links. --------------------------- Cable Wirelist : IBM Printer Port -> Facit 4070 Punch PC Punch Strobe (1) o----------------o PI (11) [Punch Instruction] D0 (2) o----------------o Ch1 (1) [Channel 1] D1 (3) o----------------o Ch2 (2) [Channel 2] D2 (4) o----------------o Ch3 (3) [Channel 3] D3 (5) o----------------o Ch4 (4) [Channel 4] D4 (6) o----------------o Ch5 (5) [Channel 5] D5 (7) o----------------o Ch6 (6) [Channel 6] D6 (8) o----------------o Ch7 (7) [Channel 7] D7 (9) o----------------o Ch8 (8) [Channel 8] Busy (11) o----------------o PR (12) [Punch Ready] Gnd (25) o----------------o Gnd(25) [Ground] +---o Ch9 (9) [Channel 9 - Sprocket] +---o +6V(24) [+6V output] ----------------------- [This bit applies to a special application that I used it for - hence the reference to punching card. Some of the rest of it might be useful, though] Facit 4070 Notes ---------------- [Circuit references apply to TTL logic board version 1] Increase the 1K pull-down (R54) on the PI line to about 10K since the pull-up on the IBM printer port is otherwise too high to turn on VT11. Increase the monotime of IC23 to give a bit more punch-pin drive for reliable punching on card. Set R97 to 27K and remove R129 Make sure the punch solenoids are correctly set up as per the Service Manual. (Procedure 5.1E) ------------------------ Here's the Pascal program fragments to talk to the punch. Call init_punch at the start of the program (before turning on the 4070!) and then punch_byte for each character to be punched const port_base=$278; {port were 4070 is connected} procedure init_punch; begin; port[port_base+2]:=1; {Set PI low} end; procedure punch_byte(ch:byte); begin; repeat; until (port[port_base+1] and 128) = 0; port[port_base]:=ch; port[port_base+2]:=0; repeat until(port[port_base+1] and 128) > 0; port[port_base+2]:=1; end; ---------------------------------