5 1/4 diskettes available

2019-07-10 Thread Will Cooke via cctalk
BG Micro, a surplus electronics dealer I buy from sometimes, has diskettes for sale. I don't know anything about them, but thought it may be of interest. I have no affiliation other than being a customer on their mailing list. Here is a link to the site:

Re: DEC MS630/M7609 Question

2019-07-10 Thread Lyle Bickley via cctalk
On Tue, 9 Jul 2019 23:43:17 + W2HX wrote: > Thanks, Lyle. I was reading this. I guess its wrong? > > https://en.wikipedia.org/wiki/MicroVAX > > The MS630 memory expansion module was used for expanding memory capacity. > Four variants of the MS630 existed: the 1 MB MS630-AA, 2 MB MS630-BA,

Re: DEC MS630/M7609 Question

2019-07-10 Thread Glen Slick via cctalk
> The simple answer is to install it in a uVAX2 system and see what it > says :-) Or look up the part number on one of the DRAM chips, count the number of DRAM chips, and then work out the total. If the M7609 uses 256Kbit DRAM chips (as all MS630 boards do), then 9 of them are 256KB with parity,

Re: 5 1/4 diskettes available

2019-07-10 Thread Al Kossow via cctalk
On 7/10/19 11:32 AM, Will Cooke via cctalk wrote: > https://www.bgmicro.com/4-pack-of-5-25-floppy-diskettes-with-sleeves.aspx They have hub rings, so they are probably 360K

Re: 5 1/4 diskettes available

2019-07-10 Thread Chuck Guzis via cctalk
On 7/10/19 7:14 PM, Fred Cisin via cctalk wrote: >>> They have hub rings, so they are probably 360K To add a bit to Fred's excellent explanation, I can offer the following: While the hub ring is *generally* a good indicator of "2D" versus "HD" disks, I've seen exceptions. Early 2D floppies did

Re: 5 1/4 diskettes available

2019-07-10 Thread Guy Dunphy via cctalk
At 12:25 PM 10/07/2019 -0700, you wrote: > > >On 7/10/19 11:32 AM, Will Cooke via cctalk wrote: > >> https://www.bgmicro.com/4-pack-of-5-25-floppy-diskettes-with-sleeves.aspx > >They have hub rings, so they are probably 360K And the index hole. Thanks Will, this is quite fortuitous. I've just

Re: 5 1/4 diskettes available

2019-07-10 Thread Fred Cisin via cctalk
They have hub rings, so they are probably 360K On Thu, 11 Jul 2019, Guy Dunphy via cctalk wrote: And the index hole. What about it? There were some machines that didn't use the index (such as Apple and Commodore), but they didn't care if there was one. There were some that used 10 or 16

Re: 5 1/4 diskettes available

2019-07-10 Thread Guy Dunphy via cctalk
At 07:14 PM 10/07/2019 -0700, you wrote: >On Thu, 11 Jul 2019, Guy Dunphy via cctalk wrote: >> And the index hole. > >What about it? Because it's so long since I used any 360K floppies, that I could not recall if some didn't have any hole. (But I did remember about the soft/hard sectoring; 1 vs

Re: 5 1/4 diskettes available

2019-07-10 Thread Guy Dunphy via cctalk
At 08:27 PM 10/07/2019 -0700, Grumpy Ol' Fred wrote: >The 5.25" diskette or "Mini-diskette" is bar napkin size, because Dr. Wang >said that 8" diskettes were too big. I have not been able to track down >WHICH bar. Perhaps the same bar where someone bet L Ron Hubbard that he couldn't create a

Re: 5 1/4 diskettes available

2019-07-10 Thread Fred Cisin via cctalk
"360K" - 300 Oersted. vs 1.2M 600 Oersted. On Thu, 11 Jul 2019, Guy Dunphy wrote: Can you believe that is the first time I have ever heard the actual figures for the coatings? I knew the 1.2M type had a higher coercivity, thus the incompatibility. Ditto with 3.5" 720K vs 1.44M. Then add to

Re: DEC MS630/M7609 Question

2019-07-10 Thread Paul Anderson via cctalk
DEC used to use the first letter of the suffix for density, and the second letter for the chip manufacturer. On Wed, Jul 10, 2019 at 12:08 PM Glen Slick via cctalk < cctalk@classiccmp.org> wrote: > > The simple answer is to install it in a uVAX2 system and see what it > > says :-) > > Or look up

Re: 5 1/4 diskettes available

2019-07-10 Thread Fred Cisin via cctalk
On Wed, 10 Jul 2019, Chuck Guzis via cctalk wrote: While the hub ring is *generally* a good indicator of "2D" versus "HD" disks, I've seen exceptions. Early 2D floppies did not use the hub ring and I've got a few HD ones that do. The hub ring thing is a story in itself, which I've gone into in