>From GA24-3073-8_1403_printer.pdf on bitsavers, in figure 4, it looks like 48 train characters align with 132 print positions, and gcd(132,48) = 12 chain characters, or every 11th print position, can be aligned at once. (Chain printers are all except 3 and N1.)
The formula on page 27 indicate that it takes about 240*0.000729s, or 0.175s for the train to go around in the N1, and 240*0.001665s, or 0.400s on the chain printers. With 240 characters, those are 729us and 1665us for the chain/train to move one chain/train character position, or to move 132/48 print character positions. As noted above, every 11th print position is aligned at once, so 1/11 of that between hammer firing positions. So, for the non-N1 1665us*48/132/11 or 55us, and, assuming the other numbers are the same, 729us*48/132/11 or 24us for the N1. The character print speed on the N1 and 3 is about twice as fast as the other models. I don't see anything saying that the spacing of the characters on the train and chain printers is different. Every 11th print position for simultaneous firing sounds closer to what I remembered, and makes it easier to build power supplies (which have to supply peak current). It only takes a small shift in the spacing, though, for a very different value. -- glen ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
