From mboxrd@z Thu Jan 1 00:00:00 1970 From: grog at lemis.com (Greg 'groggy' Lehey) Date: Tue, 10 Nov 2020 11:48:03 +1100 Subject: [COFF] Daisy wheel printers (was: [TUHS] The Elements Of Style: UNIX As Literature) In-Reply-To: References: <175409f6-af94-601e-3db3-a5af5d7f64d0@gmail.com> <20201106225825.GE99027@eureka.lemis.com> <20201109043619.GO99027@eureka.lemis.com> Message-ID: <20201110004803.GQ99027@eureka.lemis.com> On Tuesday, 10 November 2020 at 9:08:44 +1100, Dave Horsfall wrote: > On Mon, 9 Nov 2020, Greg 'groggy' Lehey wrote: > >> The Qume printers seemed to have been the best round 1980 when we used >> them in our applications. In particular, a large choice of wheels and >> fine-grained spacing. I forget how the spacing worked. > > Presumably some sort of a table lookup, based on which character is about > to be hit? Or are you referring to the micro-spacing itself? "Yes". As I said, I forget. I have a feeling that it must have been explicit micro-spacing, since the machine didn't know anything about the kind of daisy wheel that was fitted. >> The golfball console for the /360 was much earlier than that, like the >> /360 itself. The model numbers I recall were 735, and the newer >> generation 2731/2735. The last digit related to the carriage width >> (11"/15"). > > I once had a fine collection of goofballs (as we called them); sadly lost > in a house move :-( I was going to say "ditto", but I think I actually sold them along with the 735. >> Round the time in question I bought a second-hand 735 machine. It had >> an arcane interface that directly talked to the magnets. I built an >> interface for it to a parallel port [...] > > I'd like to know a bit more about that interface... You'd have to > control the carriage, roller, swivel/tilt/hit etc. Yes, I'm trying to recall that too. The ball itself was controlled by 6 signals: Up 1, up 2 (for the 4 rows of characters), left 1, left 2, left 2 (yes, twice) and right 5, for a total of 11 columns. But my recollection was that I only had about 10 power transistors driving the thing. I wish I had kept more details. Maybe there's something amongst the useless junk in the shed. > How did you detect the BREAK key to get the 360's attention and > unlock the keyboard? I didn't. The 735 doesn't have a BREAK key. It was a typewriter, not a teletype. I used it as a printer in addition to a normal glass TTY. Greg -- Sent from my desktop computer. Finger grog at lemis.com for PGP public key. See complete headers for address and phone numbers. This message is digitally signed. If your Microsoft mail program reports problems, please read http://lemis.com/broken-MUA -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 163 bytes Desc: not available URL: