On Fri, 8 Sep 2023, Liam Proven via cctalk wrote: He has an "About Me" page,and even his CV, but goes to some effort to avoid stating his NAME! (Jonathan Pallant) -- Grumpy Ol' Fred cisin(a)xenosoft.com

On Fri, 8 Sep 2023, Liam Proven via cctalk wrote: https://github.com/thejpster When Ronald Reagan got into politics, I wrote him a postcard pleading him NOT TO. I said, "Hollywood needs you." -- Grumpy Ol' Fred cisin(a)xenosoft.com

The Apple Disk ][ information needs some editing as well. And then there's the part suggesting the Commodore 1541 was more popular than the Disk ][. What utter pishposh. On Fri, Sep 8, 2023 at 3:04 PM Liam Proven via cctalk <cctalk(a)classiccmp.org> wrote: Which were continuations of policies under Carter, that started with Ford, that began with Nixon, that initiated under Johnson, that originated with Kennedy, that were rooted in what Eisenhower did, which was based on Truman policies, inspired by Roosevelt....... Sellam

On Fri, Sep 8, 2023 at 4:02 PM Fred Cisin via cctalk <cctalk(a)classiccmp.org> wrote: I've seen one in the wild before, but the guy didn't want to sell it with the pile of Lisas I bought from him. It's possible I have documentation for it. Does "more popular" mean sold more units, or does it mean better liked by I'm positive the Disk ][ was better liked by its owners than that glorified tape drive called the 1541. I sold one of those within the past couple years. I think it's something the author wrote in one fell swoop, i.e. "everything I know about floppy disks". Sellam

On Sun, 10 Sept 2023 at 15:16, Jay Logue via cctalk <cctalk(a)classiccmp.org> wrote: Yes, me. I pointed him at Fred's response, he was very pleased, and he's updated it. (I can't see much difference but I am not so expert as Mr Cisin at this stuff. There's a revision history on Github. Aside: Also on Github if you know where to find me is my own 25YO website, which I recently recovered from the Internet Archive, fixed a few links, and re-uploaded. I am wondering what to do with it. It needs 23 years of maintenance and who has the time? I saw a post somewhere -- can't find it now -- on hosting a homepage _without using HTML_ which was very impressive. I am considering doing this, and rather than trying to update my awful 1990s HTML, actually downgrading it. Did anyone see that site? It was a mixture of plain text and a tiny bit of Unicode cleverness, I think. -- Liam Proven ~ Profile: https://about.me/liamproven Email: lproven(a)cix.co.uk ~ gMail/gTalk/FB: lproven(a)gmail.com Twitter/LinkedIn: lproven ~ Skype: liamproven IoM: (+44) 7624 277612: UK: (+44) 7939-087884 Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053

On 9/10/23 07:35, Joshua Rice via cctalk wrote: Early Sonys were indeed 70 track, single-sided--and for several versions, 600 RPM. A PC controller that can handle 3.5" HD floppies will also handle the early Sony drives. I'm trying to recall if there was a head-load solenoid in those also. I believe so. There are 40 track derivatives; used for word processing, particularly on some Brother models. No big deal; when reading those, one simply double-steps a "normal" drive. In any case, as far as I recall, they all used Brother's proprietary GCR encoding. I've processed a couple hundred of those. Brother WP drives are a bit unusual in that there's no track 0 sensor. The drive simply bangs the head carriage against a stop and then micro-steps to where it finds track 0 data. This creates a problem when using "normal" 3.5" drives--I keep about 3 around with varying degrees of misalignment to handle those. Now, let's talk about 2.8" and 3.25" drives; UK readers are certainly familiar with 3.0 inch CF drives used on Amstrads. Then there are the oddball cases. Caleb UHD drives and 3M Superdisks... --Chuck

On Sun, Sep 10, 2023 at 05:44:59PM +0100, Liam Proven via cctalk wrote: [...] One unusual and interesting thing about the Amstrad PCW is how it uses a display list system, unlike basically any other home computer of the era apart from the Atari 8-bits and the Amiga. This lets it have a nice high-resolution bitmap display and do *partial* scrolling quickly without having to get the CPU to copy the whole screen around. This is obviously useful for a word processor which mostly just inserts and delete lines and makes the thing so much smoother to use. Various of its contemporaries such as the Beeb, CPC or PC video cards used or were inspired by the MC6845 CRTC that can only scroll the entire screen. This is fine for a dumb terminal experience such as the MS-DOS shell, but has to fall back to CPU rendering for partial scrolls. You can see the difference on a Beeb or emulator. Go into MODE 1 and type in any old junk such as "*HELP" to print a wodge of text. Towards the bottom, do "COLOUR 129" to set the text background to red (not strictly necessary, but it makes the changed area bigger and more obvious) and do that "*HELP" or whatever to make it scroll. Watch how the screen scrolls quickly with no tearing. That's using 6845 hardware scrolling. Now repeat this but do VDU 28,1,30,38,1 to set up a text viewport which is one character in from each edge and do the same. Look how it scrolls slowly and tears. That's software rendering making a pig's ear of it because there's just not enough memory bandwidth to copy a screen's worth of memory within a 20ms frame. This hardware scrolling support is more useful to the PCW than the CPU. If it had a 68000 in it, but no display list, it'd be much slower at editing text. Just look at wordprocessors on the original 128k Mac.

On 9/10/23 09:44, Liam Proven via cctalk wrote: From my PCW tinkerings--I bought it for the CF drive, so it was mostly a curiosity with me. I think the base unit (120VAC) was sold by Sears in the US for a time. I grabbed one locally and upgraded the RAM to 512K and a 3.5" 720K drive (Teac FD235F)--the READY line is required for operation. I noted that changing a single byte in the boot code enabled support for DS media. But the "no ROM" claim should probably be modified to "no discrete ROM", as I believe the boot code is contained in the printer controller and is strobed onto the Z80 bus at IPL time. Almost certainly mask-programmed. The PCW, although interesting languished in my shop for about a decade. Finally was contacted by someone who was willing to drive up from California and relieve me of it. He also received an AT&T 6300 for his troubles. I am loath to recycle old interesting gear, but am willing to give it away to interested parties. --Chuck --Chuck

On 9/10/23 12:39, Fred Cisin via cctalk wrote: Got some of those in my rogue's gallery too. The thing that seems to be lost on many is that legacy (i.e. Shugart-interface) floppy drives are very dumb devices. Pretty much don't care what you put on them, so long as it satisfies the bandpass requirements. --Chuck

On 9/10/23 13:00, Fred Cisin via cctalk wrote: Can't say, but probably. I've got an 8" disk here written by an Apple II. Encoding is weird--basically the Apple RWTS encoded as 8 bit FM (3740) bytes. Haven't bothered to see from whence it came. --Chuck

On 9/10/23 13:31, Fred Cisin via cctalk wrote: Have no idea, but was surprise to see RWTS encodings in standard FM. --Chuck

On Sun, 10 Sep 2023, Sellam Abraham via cctalk wrote: I have no idea about the format(s) supported with that board. Possibly FM (for 8"SSSD, which is what the Flagstaff Engineering modified 5150 FDC was for) Possibly MFM (for 5150 disks, but could also, with appropriate additional software handle thousands of others) Could it have also had support for pseudo Apple-DOS (and Apple CP/M, P-System, ProDOS), so that machines with that controller, but without also Apple drives, could run Apple software/programs, once copied to an FM pseudo AppleDOS format? -- Grumpy Ol' Fred cisin(a)xenosoft.com

I make an official motion that Fred write his own "Everything I Know About Floppy Disks" page / book /encyclopedia. I suspect that what is inside his head is the greatest collection of knowledge about floppies on the planet. Fred, you will be paid with great admiration and appreciation. Sorry, all I can offer. :-) Anyone with me? Will If you want to build a ship, don't drum up people to collect wood and don't assign them tasks and work, but rather teach them to long for the endless immensity of the sea. Antoine de Saint-Exupery

Anyone who wants to resuscitate either old drives, or recover data from old disks. There is a lot of such data... Also, history is important. Not always in obvious ways, but if it's lost it tends to be very hard to recover. One of my favorite examples of old history is the Ph.D. thesis of Gauthier van den Hove (U. Amsterdam, a few years ago) analyzing in extreme detail the world's first ALGOL-60 compiler, by Dijkstra and Zonneveld. Why bother? Well, for one, because it wasn't just the first compiler but the place where a whole bunch of later-standard techniques were first invented, and understanding the origin of things and what problems they solve and why they do it that way can be surprisingly important. paul

Not sure about the language, but at this point most of its programmers have memory leaks. Will If you want to build a ship, don't drum up people to collect wood and don't assign them tasks and work, but rather teach them to long for the endless immensity of the sea. Antoine de Saint-Exupery

Correct. I don't know the 68R subset specifically. ALGOL 68 certainly has pointers, and heap storage, where objects remain in existence so long as something refers to them. That's similar to the model of BASIC strings, or Python objects. Garbage collection or reference counting arethe usual way to deal with unreferenced objects, though things get tricky when circular references are possible. :-) The reason C and C++ have memory leaks is that they are low level languages where there is no linkage between the lifetime of objects and the existence of references to them, nor in fact a way for the implementation to know whether there are references. By constrast, in strongly typed languages like ALGOL-68 or Pascal or Ada, and even in languages like Python, that question does have a clear answer so memory management can be done by the implementation rather than left to the tender mercies of the programmer. paul

On Sun, Sep 10, 2023, 4:12 PM Will Cooke via cctalk <cctalk(a)classiccmp.org> wrote: I am. I thought I was hot shit with what I knew about floppies. And for the tiny sliver I needed for my Rainbow hacking, I kinda sorta knew enough. This thread and all the others shows I know next to nothing. Warner

On Sun, 10 Sep 2023, Joshua Rice via cctalk wrote: Yes, my sentence is twisted into knots :-) Those were fascinating. 600 RPM and full height I agree that They were indeed, probably a derivative, rather than a predecessor. Although I think that it was an early derivative. "Ordinary" 3.5" is 135 tpi with 80 tracks. Epson, and very few others, briefly tried 67.5 tpi, 40 track. Epson Geneva PX-8, etc. I had a 67.5 tpi drive from another manufacturer, which means that somebody expected it to catch on, or they thought that there would be a market for Epson accessories? The apparently earliest 3.5" diskettes did not have a shutter. I have (or had) a few labelled "Shugart". It is possible that those might have been from a large batch of prototoypes for development, rather than commercially available. Then came manual "pinch" shutters. The user slid the shutter open, and it latched. After removing the disk, the user pinches the corner of the disk and a spring closes the shutter. The spot to pinch on the corner of the disk had a tiny arrow pointing to it, and the word "Pinch". Then came modern automatic shutters. The word "Pinch" is gone, but on many of them, the arrow remained! At Comdex, somebody at one of the disk manufacturers told me, "That arrow is a reminder of which direction to insert the disk." I don't think that he believed me when I told him the origin of the arrow. -- Grumpy Ol' Fred cisin(a)xenosoft.com