Micha That the board is TTL and 2 layer by the look of it makes reverse engineering rather more tractable : good luck.
The 25p D pin outs for readers/punches seem substantially standardised, I think you will find that the Dostek 440 manual (which is a solid state substitute for PTP / PTR) will get you a long way. The use case for PT after the early 70's seems to have primarily been CNC, feeding G code to machines. Additionally, the DEC PC-04/05 and PC-11 manuals / eng drws should provide a worked example from the same era (they are online). They look to be sprocket fed, and have (eg) details of motor / sprocket adjustment. You will also find Facit N4000 and 4070 documentation on line; however, 232 interfaces seem to be the prefered flavor GNT is another PTR/PTP OEM, again with some documentation online, model numbers include 36, 4601, 4604, 3406, 29 I have a Sanyo Denshi 2702 PTR (sprocket feed) which is on the gather dust manyana list. I have a serviceable friction feed / optical sense reader which I much prefer, the sprockets look to me like a paper shredding mechanism. HtH Martin -----Original Message----- From: Michael Fritsch via cctalk [mailto:cctalk@classiccmp.org] Sent: 16 May 2024 17:02 To: cctalk@classiccmp.org Cc: Michael Fritsch <m...@fritscholyt.de> Subject: [cctalk] Re: Papertape-Reader Decitek 442A9: need manual/schematics I know the document on bitsavers, but the series 700 is a complete different one. In this reader there is no clamp or breake or similar things, but a stepper motor which drives two sprocket wheels. Between the wheels is the optical sensor. In the moment I'm about to reverse engineer the board. The db25 connector at the back is almost completely populated. I would like to known what the pin are for. Very good, that Decitek still exists. I will write them. Micha Martin Bishop via cctalk wrote: > It looks as though Decitek remain in business > http://www.decitek.com/index.html > > Scan of a series 700 reader manual on bitsavers > http://www.bitsavers.org/pdf/decitek/ > > On an optical reader, I would not recon the capstan running at power on as > unusual - a pinch roller which engages for drive and a tape clamp engaging > for stop motion are both common features. For simple single byte read > operations, probably the paradigm used when the unit was built, it is not > uncommon for the sprocket hole to stop feed and energise clamp. The > circuitry to control this behaviour may be in the drive or controller or > shared; and then there are configuration links / switches ... > > An empirical approach is to scope / LA the sprocket and data bit outputs; > ideally with a tape loop. > > HtH; Martin >
