[cctalk] Re: Greaseweazle part 2
Is it really necessary to be always so confrontational? It is unpleasant. On Sun, 11 June 2023, 10:44 pm Tony Duell via cctalk, wrote: > > Fundamentally, it seems to me that they're all the same basic hardware, > > timing intervals between flux transitions. > > > > So other than the soaftware, what's the difference? > > I could make a stupid comment and ask 'what's the difference between a > PDP8, PDP11, PERQ or HP9830?'. Apart from having finite memory, all > are (I believe) equivalent to a Turing machine. > > But more seriously when I started asking about writing images to > floppy disks, I asked what options were available and what I'd need. > Apart from the (IMHO) stupid suggestion of a 1990's PC compatible, the > only thing that was mentioned to me was the Greaseweazle. Nobody > pointed me at web sites giving comparisons between the various methods > and devices. > > -tony >
[cctalk] Re: Getting floppy images to/from real floppy disks.
On Sun, Jun 11, 2023 at 9:07 PM Sellam Abraham via cctalk wrote: > "While I don’t recall saying that, I may well have - I know that I was > involved in the engineering question of how safe it would be to use. > > The inverter produced 230 VDC, which it turned out could be safely fed to > the 120VAC input without more than a single diode drop reverse voltage > across an electrolytic filter capacitor. This was due to the power supply’s > design having a voltage doubler as the first stage. I find that curious (read : I don't see how it could work, at least not reliably.) The power supply in the Osborne 1 and 1A is an Astec SMPSU. The input stage is the conventional one. Mains input goes through a filter circuit to a bridge rectifier. The output of the bridge rectifier goes to 2 electrolytic capacitors in series. There is a voltage selector link between one side of the AC input to the bridge rectifier and the centre tap of the capacitors. In the Osborne 1, this link is hidden on the PSU board and you have to dismantle the machine to get to it. On the 1A it's set by a little plug-in PCB in the mains input module on the back which you turn round for 115V or 230V mains. On 115V the link is in place. 2 of the diodes in the bridge and the 2 capactors form a voltage doubler circuit. Each capacitor charges to about 160V. You get 320V across the pair to feed the chopper. On 230V, the link is open. The bridge rectifier works as you might expect, the 2 capacitors get around 320V across them and charge equally (so about 160V on each). Again 320V to the chopper. Now if you feed in 230V DC with the link in the 115V position, one capacitor (only) will charge to the full 230V. That is more than the working voltage of said capacitor. The other will not charge at all from the input. Meaning the chopper circuit is fed from the charged capactior with another one in series. That one is liable to charge up with a reverse polarity due to the action of the chopper. Bang! -tony
[cctalk] Re: Getting floppy images to/from real floppy disks.
On Mon, Jun 12, 2023 at 1:25 AM Chuck Guzis via cctalk wrote: > > I'm a bit surprised that there don't seem to be any adaptations that > hook into the head pre-amps and use an ADC to give a view of what the > read signal actually looks like. Maybe that's asking too much--there > are certainly MCUs with sufficiently fast ADCs and memory to do this. I suspect that would be too drive-specific for most users. Yes the head preamp outputs are nearly always available on testpoints on the drive PCB (you use them when doing a head alignment) but having to find them and connect to them could be non-trivial. At least with the flux transition interfaces all you have to do is plug into the normal drive ribbon cable connector. -tony
[cctalk] Re: Getting floppy images to/from real floppy disks.
I'm a bit surprised that there don't seem to be any adaptations that hook into the head pre-amps and use an ADC to give a view of what the read signal actually looks like. Maybe that's asking too much--there are certainly MCUs with sufficiently fast ADCs and memory to do this. --Chuck
[cctalk] Re: Getting floppy images to/from real floppy disks.
On Mon, Jun 5, 2023 at 1:43 PM Robert Feldman via cctalk < cctalk@classiccmp.org> wrote: > >Message: 21 > >Date: Mon, 5 Jun 2023 04:35:28 +0100 > >From: Tony Duell > >Subject: [cctalk] Re: Getting floppy images to/from real floppy disks. > > > >On Sun, Jun 4, 2023 at 10:57 PM Fred Cisin via cctalk > > wrote: > >> > >> On Sun, 4 Jun 2023, Rick Bensene via cctalk wrote: > <> > an example of early "mobile computing". (Tongue firmly in cheek). > >> > >> The original Osborne 1 had a 12V power input! > > > >Actually it's +12.6V and +5.6V and you have to supply both voltages. > >It's one diode drop to the +5V (logic supply) and +12V (DRAM, disk > >motors, monitor supply), the -5V for the DRAM is produced on the logic > >board. > > > >I am told it was never used and that the Osborne battery pack came > >with an inverter to provide 110V AC. > > > >-tony > > It (the Osborne Powr-Pac (tm) ) has a what the manual says is a DC-DC > inverter that plugged into a Gould lead-acid battery (or the > cigarette-lighter socket in a car) at one end and the AC input of the > Osborne 1 at the other. I have read on this list that Lee denies that OCC > ever sold them, but I have one that I bought for $50 at Compumat in Chicago > on October 10, 1983 -- I still have the unit, receipt, and User > Registration card. It came with a glossy-printed grey-and-blue manual, like > other contemporary OCC products. > > If anyone wants a copy, I can email you a PDF scan of the user manual. > > Bob > Bob, I asked Lee if he could respond to this and here it is: "While I don’t recall saying that, I may well have - I know that I was involved in the engineering question of how safe it would be to use. The inverter produced 230 VDC, which it turned out could be safely fed to the 120VAC input without more than a single diode drop reverse voltage across an electrolytic filter capacitor. This was due to the power supply’s design having a voltage doubler as the first stage. It was designed by a third party who presented it to Osborne who accepted it as a branded product - exactly how they supplied it is something I don’t know (did the third party handle the production or did we?). If the question had ben posed to me as to whether it was a “battery pack” I might well have answered no because it never included batteries. Apologies for any confusion - I was always overloaded at Osborne and no one knew what a VP of Engineering’s job was until John Hanne came in in 1983. I was relabeled “R&D Fellow” in 1981 and replaced with Ed Richter." (I did get Lee's permission to post this, which was the cause of the delay in posting this as he hadn't seen my first request.) Sellam
[cctalk] Re: Greaseweazle part 2
I would have liked to find that comparison site earlier. However I think I'd still have gone for greaseweazle. On Sun, 11 Jun 2023, 09:29 Tony Duell via cctalk, wrote: > Well, I've got the Greaseweazle software to run, but I don't know why, > which is hardly encouraging. > > Installing various Windows updates, downloading .dlls, and puting the > latter in various directories changed the error messages but it never > actually worked. But downloading the latest Greaseweazle software did, > it ran first time. So no idea what I was doing wrong (maybe 32 bit > .vs. 64 bit Windows applications?) > > I can now get the list of commands when I run gw.exe. And can get help > on them using the -h option. I've not tried connecting a drive yet, > but the software can find and talk to the board (the green 'activity' > LED turns on). For example 'gw rpm' which is used to check the drive > speed by timing the index pulses times out and gives a 'no index' > error which seems entrely reasonable. > > However I am not sure if I'll be able to use it. There is one very > important thing missing : DOCUMENTATION. The 'wikii' on github is > ridiculously incomplete. There is no user manual or man pages. The > software source in python (a language I've never used) has very few > comments and is not clear at all. > > It's not clear to me exactly what all the options are for, and when to use > them. > > -tony >
[cctalk] Re: Greaseweazle part 2
On 6/11/23 08:21, ben via cctalk wrote: > I would of thought the AMIGA would have a say here, > as it reads a disk track as just a bunch of flux transitions. Other than the FBGA-equipped ones (e.g. Catweasel Mk 3-4) and a few others, all basically use the same "timer capture" facility in all but the most basic MCUs. For writing, one can, similarly, use the timer-based PWM facilities in the same chips. Other than timer clock rate and local RAM, they're pretty much the same from a hardware standpoint. I doubt that one can say that across the entire PDP-11 line. My own implementations use an 84 MHz timer clock (prescaling selected) with HF noise filtering and 192KB of local memory. Most of my analysis is done in the MCU, not relying on any PC/Apple host. No need for USB, (although I use it for speed and include an option to run using a UART) a dumb terminal would suffice for interface. Since the MCU includes a NIC, one could conceivable run it from a smartphone. --Chuck
[cctalk] Re: Greaseweazle part 2
On 2023-06-11 8:44 a.m., Tony Duell via cctalk wrote: Fundamentally, it seems to me that they're all the same basic hardware, timing intervals between flux transitions. So other than the soaftware, what's the difference? I could make a stupid comment and ask 'what's the difference between a PDP8, PDP11, PERQ or HP9830?'. Apart from having finite memory, all are (I believe) equivalent to a Turing machine. A: the blinking lights. But more seriously when I started asking about writing images to floppy disks, I asked what options were available and what I'd need. Apart from the (IMHO) stupid suggestion of a 1990's PC compatible, the only thing that was mentioned to me was the Greaseweazle. Nobody pointed me at web sites giving comparisons between the various methods and devices. -tony I would of thought the AMIGA would have a say here, as it reads a disk track as just a bunch of flux transitions. Ben.
[cctalk] Re: Greaseweazle part 2
> Fundamentally, it seems to me that they're all the same basic hardware, > timing intervals between flux transitions. > > So other than the soaftware, what's the difference? I could make a stupid comment and ask 'what's the difference between a PDP8, PDP11, PERQ or HP9830?'. Apart from having finite memory, all are (I believe) equivalent to a Turing machine. But more seriously when I started asking about writing images to floppy disks, I asked what options were available and what I'd need. Apart from the (IMHO) stupid suggestion of a 1990's PC compatible, the only thing that was mentioned to me was the Greaseweazle. Nobody pointed me at web sites giving comparisons between the various methods and devices. -tony
[cctalk] Re: Greaseweazle part 2
On 6/11/23 02:29, Adrian Godwin via cctalk wrote: > Sorry to drip-feed this, but > https://wiki.archiveteam.org/index.php/Rescuing_Floppy_Disks is a useful > source on comparing various methods. It's clear that this type of interface > has particularly strong support on Apple due to their previous use of > non-IBM formats, and Amiga is also quite common (I think that's where > greaseweazle started). Fundamentally, it seems to me that they're all the same basic hardware, timing intervals between flux transitions. So other than the soaftware, what's the difference? --Chuck
[cctalk] Re: Greaseweazle part 2
Sorry to drip-feed this, but https://wiki.archiveteam.org/index.php/Rescuing_Floppy_Disks is a useful source on comparing various methods. It's clear that this type of interface has particularly strong support on Apple due to their previous use of non-IBM formats, and Amiga is also quite common (I think that's where greaseweazle started).
[cctalk] Re: Greaseweazle part 2
Further on the greaseweazle docs - there is a forum at https://github.com/keirf/greaseweazle/discussions which seems quite lively and may be the right place to start. On Sun, Jun 11, 2023 at 9:56 AM Adrian Godwin wrote: > On Sun, Jun 11, 2023 at 9:29 AM Tony Duell via cctalk < > cctalk@classiccmp.org> wrote: > >> However I am not sure if I'll be able to use it. There is one very >> important thing missing : DOCUMENTATION. The 'wikii' on github is >> ridiculously incomplete. There is no user manual or man pages. The >> software source in python (a language I've never used) has very few >> comments and is not clear at all. >> >> It's not clear to me exactly what all the options are for, and when to >> use them. >> >> -tony >> > > I also got one ion the hope I'd be able to read a 1.44MB dos floppy that > may or may not have some useful software on it. > It installed and ran without issue on Linux but, like Tony, I'm finding > the documentation a bit short. And I don't know much python either though I > do find it fairly readable. > > I have tried the examples that do exist and they work as described. It's > not clear though yet how to proceed though in the simplest case I think it > has provided me with a 1.44MB image of a test floppy. Using it for non-DOS > floppies may be more difficult but the main reason I'm unsure is that it's > fairly quiet about what it does and I don't know yet how much recovery work > it's done unbidden. I do believe the greaseweazle firmware includes some of > the retry mechanism and may 'just work'. Note that the test floppy I'm > using is easily readable. > > However, while I was waiting for the board, I looked around for software > and as well as that recommended by the designer I also found some called > fluxengine. This was written for a different adapter - actually a Cyprus > dev board connected directly to a floppy socket, not a custom board, but it > supports the greaseweazle adapter and only lose part of the functionality. > I haven't investigated the documentation on that yet but it's very well > presented and I have hopes that I wil be able to use it too. I'd recommend > looking at it - it was very little trouble to get working. I didn't try it > on Windows but it has support for that. > https://github.com/davidgiven/fluxengine > > I think there were a couple of recommendations for greaseweazle here so I > guess someone's found it useful before. I'm interested in any hints - if > you send any to tony please cc me. > > Although Tony seems to have resolved his Windows problems, it did occur to > me that this could be paired with a raspberry pi or clone to make a > self-contained device with little cost or effort. > > -adrian >
[cctalk] Re: Greaseweazle part 2
On Sun, Jun 11, 2023 at 9:29 AM Tony Duell via cctalk wrote: > However I am not sure if I'll be able to use it. There is one very > important thing missing : DOCUMENTATION. The 'wikii' on github is > ridiculously incomplete. There is no user manual or man pages. The > software source in python (a language I've never used) has very few > comments and is not clear at all. > > It's not clear to me exactly what all the options are for, and when to use > them. > > -tony > I also got one ion the hope I'd be able to read a 1.44MB dos floppy that may or may not have some useful software on it. It installed and ran without issue on Linux but, like Tony, I'm finding the documentation a bit short. And I don't know much python either though I do find it fairly readable. I have tried the examples that do exist and they work as described. It's not clear though yet how to proceed though in the simplest case I think it has provided me with a 1.44MB image of a test floppy. Using it for non-DOS floppies may be more difficult but the main reason I'm unsure is that it's fairly quiet about what it does and I don't know yet how much recovery work it's done unbidden. I do believe the greaseweazle firmware includes some of the retry mechanism and may 'just work'. Note that the test floppy I'm using is easily readable. However, while I was waiting for the board, I looked around for software and as well as that recommended by the designer I also found some called fluxengine. This was written for a different adapter - actually a Cyprus dev board connected directly to a floppy socket, not a custom board, but it supports the greaseweazle adapter and only lose part of the functionality. I haven't investigated the documentation on that yet but it's very well presented and I have hopes that I wil be able to use it too. I'd recommend looking at it - it was very little trouble to get working. I didn't try it on Windows but it has support for that. https://github.com/davidgiven/fluxengine I think there were a couple of recommendations for greaseweazle here so I guess someone's found it useful before. I'm interested in any hints - if you send any to tony please cc me. Although Tony seems to have resolved his Windows problems, it did occur to me that this could be paired with a raspberry pi or clone to make a self-contained device with little cost or effort. -adrian
[cctalk] Greaseweazle part 2
Well, I've got the Greaseweazle software to run, but I don't know why, which is hardly encouraging. Installing various Windows updates, downloading .dlls, and puting the latter in various directories changed the error messages but it never actually worked. But downloading the latest Greaseweazle software did, it ran first time. So no idea what I was doing wrong (maybe 32 bit .vs. 64 bit Windows applications?) I can now get the list of commands when I run gw.exe. And can get help on them using the -h option. I've not tried connecting a drive yet, but the software can find and talk to the board (the green 'activity' LED turns on). For example 'gw rpm' which is used to check the drive speed by timing the index pulses times out and gives a 'no index' error which seems entrely reasonable. However I am not sure if I'll be able to use it. There is one very important thing missing : DOCUMENTATION. The 'wikii' on github is ridiculously incomplete. There is no user manual or man pages. The software source in python (a language I've never used) has very few comments and is not clear at all. It's not clear to me exactly what all the options are for, and when to use them. -tony
