Tony, maybe your collection can help me answer a puzzle: which side is "top"? By my reading, for 8-level tape, - ANSI and other US standards have three data bits / index / then five data bits - ECMA has five/index/three... :) https://twitter.com/33asr/status/1138758004747177984
On Fri, May 1, 2020 at 12:05 PM Tony Duell via cctalk <cctalk@classiccmp.org> wrote: > On Fri, May 1, 2020 at 4:48 PM Anders Nelson via cctalk > <cctalk@classiccmp.org> wrote: > > > > Wow, what a response! Really appreciate the docs and first-hand > experience, > > this is super helpful. > > I feel very greedy now. Looking arounds I have (not all working, but > all could be got to work, it's things like drive belts I need to get ) > > 3 Facit 4070s and an N4000 > A DEC PC04 > Two Data Dynamics units (1130 and 1183) which are 8-level punches > 3 Teletype BRPEs > A Trend Paper Tape Station (GNT 34 punch and Trend HSR500 reader in a > rack chassis) > A couple of Teletype Model 33 ASR's > A Friden Flexowriter with punch/reader > The punch from a Flexowriter on a rack chassis with its own motor. > > I think there's a couple of bare-chassis solenoid-operated punches > here too but I would have to hunt for them. > > And that's the 8 level ones. For 5 level (only) I have a Creed 444 > teleprinter and a Booth-Willmott Model 44 Keypunch (totally mechanical > between the keyboard and the 5 punch pins so not much use for computer > interfacing). > > > > > > > I'm also floored by the complexity of that Roytron punch! Looks like it > > contains around one hundred separate parts. I'm convinced the punch parts > > will have to be precision metal so while that's not quite "DIY" it might > > still be a reasonable bit to CNC, mill or water-jet cut. > > > > It also looks like that punch has an escapement mechanism of some sort? > > Seems like a simple way to keep regular spacing, but if course more parts > > to buy from McMaster Carr or whatever. > > Some punches fed the tape with a sprocket wheel, one way to drive that > is a suitably toothed ratchet wheel and drive pawl that moves it one > tooth per punch cycle. As I said in another message, the Facit 4070 > uses an accurately-machined (right diameter) capstan and pinch roller, > the capstan moves the tape one chracter spacing for a certain number > of steps (it _may_ be just one step) of the motor. I have another > punch unit here which has the crank-and-interposer mechanism to punch > the holes but has as sprocket with its own stepper motor to feed the > tape. Different manufacturers did it in different ways. > > > > > Question: did all tapes have indexing holes separate from the drive > > Eh? The sprocket holes _are_ the indexing holes, surely? > > > sprocket holes? Also is there a source for tape with sprocket holes > anymore? > > Every punch I've seen (and own) can punch the sprocket holes on > totally blank tape. Some insist on doing it (there's no way to punch a > character without a sprocket hole), for others the sprocket punch is > just another pin operated by the same type of mechanism as the data > punches and you have to fire the solenoid at the right time if you > want a sprocket hole. > > -tony >