Re: SMD disk specifications
On 12/15/19 10:22 PM, Mattis Lind via cctalk wrote: While the CMD and SMD drives could be used on the same host interface the Hawk could not since the interface was different from the SMD interface. I've been told by someone who worked down in OK that there were MANY different OEM variations of the Hawk. I probably have a dozen sets of manuals for them scanned but not on line. They all share similar Diablo/Pertec style interfaces.
Re: SMD disk specifications
måndag 16 december 2019 skrev Eric Smith via cctalk : > On Sun, Dec 15, 2019 at 3:05 AM jim stephens via cctalk < > cctalk@classiccmp.org> wrote: > > > I don't know that I recall SMD being a product as much as a reference to > > the interface they had though. > > > > "SMD" was in fact a product name. The CDC976x, BK4XX, BK5XX, BK6XX, and > BK7XX series drives had the official name "CDC(R) Storage Module Drive", > from whence came the "SMD" name for the interface, starting with the 9760 > in 1973. MMD and CMD drives came along a few years later. AFAIK the MMD > drives weren't too popular in the early years, but gained traction in the > 1980s. CMD drives, on the other hand, were an instant hit, starting with > the 9427 "Hawk" drive in 1977. > The Hawk was quite different from the Phoenix. Actually it was not a Cartridge Module Drive, rather it was called Cartridge Disk Drive. While the CMD and SMD drives could be used on the same host interface the Hawk could not since the interface was different from the SMD interface.
Re: SMD disk specifications
I could probably lend it out, as I have a hacked copy of RSX11M on it. First I have to find the controller/power supply. Will check around next time I'm up in the attic. C On 12/15/2019 4:57 PM, Al Kossow via cctalk wrote: On 12/15/19 12:47 PM, Chris Zach via cctalk wrote: Oddly enough I have a 9457 Lark out in the shed. I've been looking for one for a while to try to recover an early Sun Unix if you don't have a need for it.
Re: SMD disk specifications
On Sun, Dec 15, 2019 at 12:31 PM shad via cctalk wrote: > I have two CDC Lark Disk modules I would like to revive, they are in good > [...] > IIRC there was a sort of adapter board between SMD and (xxx blank spot) > interface. There was a description of the interface, it was really similar > to SMD, but wasn't SMD... > LDI, Lark Device Interface. Not really all that similar to SMD. CDC offered an SMD-to-LDI adapter. Maybe I should check again the Lark model number. > The ones I've seen were 9457, but there was also a 9455 which had a wider track pitch resulting in it having roughly 1/3 the tracks and 1/3 the capacity of the 9457.
Re: SMD disk specifications
On Sun, Dec 15, 2019 at 3:05 AM jim stephens via cctalk < cctalk@classiccmp.org> wrote: > I don't know that I recall SMD being a product as much as a reference to > the interface they had though. > "SMD" was in fact a product name. The CDC976x, BK4XX, BK5XX, BK6XX, and BK7XX series drives had the official name "CDC(R) Storage Module Drive", from whence came the "SMD" name for the interface, starting with the 9760 in 1973. MMD and CMD drives came along a few years later. AFAIK the MMD drives weren't too popular in the early years, but gained traction in the 1980s. CMD drives, on the other hand, were an instant hit, starting with the 9427 "Hawk" drive in 1977.
Re: SMD disk specifications
Oddly enough I have a 9457 Lark out in the shed. The trick is the SMD to whatever it is connection is made in the power supply box, there is a ribbon cable going from the box to up to two drives and an SMD interface on the other side. Do you have the power supply? C On 12/15/2019 2:31 PM, shad via cctalk wrote: Hello, well maybe my memory has blank spots. I have two CDC Lark Disk modules I would like to revive, they are in good shape, but only one has a cartridge included, and they are not identical. Not sure if the other one could be employed without cartridge. I never found a manual with exact model correspondence, I found years ago a manual for very similar drives. IIRC there was a sort of adapter board between SMD and (xxx blank spot) interface. There was a description of the interface, it was really similar to SMD, but wasn't SMD... Maybe I should check again the Lark model number. Andrea
Re: SMD disk specifications
On 12/14/2019 10:58 PM, Eric Smith wrote: According to CDC and MPI documents on various drives, and the SMD/MMD/CMD specification document: SMD = Storage Module Drive MMD = Mini-Module Drive CMD = Cartridge Module Drive These were separate groups of products, though they obviously had similarities, and the interface was essentially identical. Those definitions are correct, but there was no no difference in the data interface that we ever worried about with our product. I don't know that I recall SMD being a product as much as a reference to the interface they had though. I've got an MMD160 I hope to restore. When we were selling systems, we had both 80mb CMD and 80mb MMD's and they had identical specs as far as heads and tracks. Main difference was the CMD top disk could crash as it wasn't totally sealed. And our application had no provision to use a removable platter. But we ran with the CMD without any problem just to be sure. There was an EMD line that CDC came out with which had two drives in the space occupied by an MMD. If I recall I think the transfer rate was about twice the rate of the MMD, with larger numbers of bits / track. For our design, we used a CRC chip to generate and check the recording. When the EMD came out, we couldn't get our design modified to use the preferred ECC chip, and the logic couldn't keep up with the data rate. So the controller we had stuck with the original interface. Thanks Jim thanks Jim
Re: SMD disk specifications
On Sat, Dec 14, 2019 at 2:47 AM jim stephens via cctalk < cctalk@classiccmp.org> wrote: > CMD was the name of the division that manufactured the disks, The division was Magnetic Peripherals Inc. (MPI). I've never heard of it having been called CMD either before or after it was called MPI. There was an (AFAIK) entirely unrelated company named CMD Technology Inc. that made disk controllers. FWIW. Not heard of CDC calling it anything other than SMD. According to CDC and MPI documents on various drives, and the SMD/MMD/CMD specification document: SMD = Storage Module Drive MMD = Mini-Module Drive CMD = Cartridge Module Drive These were separate groups of products, though they obviously had similarities, and the interface was essentially identical. > It was their golden goose, so though it's not really a spec, reading the > specs of any CDC > drive of an equivalent capability as you are looking for is probably > what any standard would contain. There's most definitely an interface specification that is not specific to any given drive. For original SMD/MMD/CMD, it is CDC document 64712400, which went through many revisions, some of which can be found on bitsavers: http://bitsavers.org/pdf/cdc/discs/interface_specs/64712400_SMDCableSpec_Mar81.pdf The technical specifications of any given drive model give a substantial faction of the interface specification, but not necessarily all of it. There are optional features that may not be implemented in a particular drive model, and a model may have minor deviations from the spec. Also the interface specification may allow broader ranges of characteristics than are documented for any given drive. If you're designing an SMD controller or an SMD drive, you should definitely design to the interface specification, though looking at individual drive model specs is also informative. Unfortunately the later CDC specification for the SMD-E interface (a superset of the SMD interface) does not seem to be available anywhere. I think the ANSI specification covers SMD-E, but I'm not 100% certain.
Re: SMD disk specifications
Thanks Eric, I somehow missed that one. TTFN - Guy > On Dec 13, 2019, at 11:42 AM, Eric Smith wrote: > > On Fri, Dec 13, 2019 at 10:55 AM Guy Sotomayor via cctalk > mailto:cctalk@classiccmp.org>> wrote: > I’ve been trying to find *detailed* specifications (mainly detailed signal > timings) for the SMD disk interface but all I’ve found so far are the > interface specifications for individual disks (CDC, Fujitsu, etc). I’ve > looked in the usual places (bitsavers mostly) and haven’t found the spec > itself. If anyone has any pointers, I’d appreciate it. > > You've seen that the SMD spec (as of March 1981) is on Bitsavers? > pdf/cdc/discs/interface_specs/64712400_SMDCableSpec_Mar81.pdf > > That doesn't cover later enhancements such as SMD-E. >
Re: SMD disk specifications
lördag 14 december 2019 skrev jim stephens via cctalk : > > > On 12/14/2019 1:10 AM, shad via cctalk wrote: > >> Hello, >> I also was searching about a clear SMD specification years ago, I found >> something in disk documentation from CDC, but doubts remain, because some >> disks call the interface SMD, some other CMD, never understood the >> difference... >> > CMD was the name of the division that manufactured the disks, FWIW. Not > heard of CDC calling it anything other than SMD. It was their golden > goose, so though it's not really a spec, reading the specs of any CDC drive > of an equivalent capability as you are looking for is probably what any > standard would contain. I think the name of the division was MPI. CMD was the Cartridge Module Drive aka Phoenix. http://bitsavers.informatik.uni-stuttgart.de/pdf/cdc/discs/CDC_Drive_Models.txt But as far as I know the interface of the SMD drives and CMD drives were identical. At least the Norsk Data ND10 used them both on the same interface in the computer end. /Mattis > The big problem they faced was there wasn't a second act for them, despite > spending huge amounts on a lot of other products. They continued using > oddball interfaces to try to pull the same stunt and people didn't fall for > it twice. > > The closesest that anyone came to challenging them was the Trident > interface, but they crashed and burned anyway. > > When did you see something called CMD? > thanks > Jim > >> Andrea >> >> >> >
Re: SMD disk specifications
On 12/14/2019 1:10 AM, shad via cctalk wrote: Hello, I also was searching about a clear SMD specification years ago, I found something in disk documentation from CDC, but doubts remain, because some disks call the interface SMD, some other CMD, never understood the difference... CMD was the name of the division that manufactured the disks, FWIW. Not heard of CDC calling it anything other than SMD. It was their golden goose, so though it's not really a spec, reading the specs of any CDC drive of an equivalent capability as you are looking for is probably what any standard would contain. The big problem they faced was there wasn't a second act for them, despite spending huge amounts on a lot of other products. They continued using oddball interfaces to try to pull the same stunt and people didn't fall for it twice. The closesest that anyone came to challenging them was the Trident interface, but they crashed and burned anyway. When did you see something called CMD? thanks Jim Andrea
Re: SMD disk specifications
On Fri, Dec 13, 2019 at 10:55 AM Guy Sotomayor via cctalk < cctalk@classiccmp.org> wrote: > I’ve been trying to find *detailed* specifications (mainly detailed signal > timings) for the SMD disk interface but all I’ve found so far are the > interface specifications for individual disks (CDC, Fujitsu, etc). I’ve > looked in the usual places (bitsavers mostly) and haven’t found the spec > itself. If anyone has any pointers, I’d appreciate it. > You've seen that the SMD spec (as of March 1981) is on Bitsavers? pdf/cdc/discs/interface_specs/64712400_SMDCableSpec_Mar81.pdf That doesn't cover later enhancements such as SMD-E.
Re: SMD disk specifications
On Fri, Dec 13, 2019 at 11:10 AM Al Kossow via cctalk wrote: > ANSI has a spec, X3.91M_1987 I don't know if it covers the SMD-E , etc. > X3.91M-1987 section 6 covers "Interface Extensions", which includes adding tag 4, 5, and 6, dual-port provisions, spinup sequencing, index mark and sector mark signals, fixed-head addressing, service voltages on round radial cable, and extended cylinder addressing. I think some of that came in with SMD-E, but I'm not 100% certain. X3.91M-1987 describes data rates of up to 24 Mbps, which came from SMD-E. SMD-E is apparently defined by CDC document 64712402, which I've never been able to obtain.
Re: SMD disk specifications
ANSI has a spec, X3.91M_1987 I don't know if it covers the SMD-E , etc. On 12/13/19 9:55 AM, Guy Sotomayor via cctalk wrote: > Hi, > > I’ve been trying to find *detailed* specifications (mainly detailed signal > timings) for the SMD disk interface but all I’ve found so far are the > interface specifications for individual disks (CDC, Fujitsu, etc). I’ve > looked in the usual places (bitsavers mostly) and haven’t found the spec > itself. If anyone has any pointers, I’d appreciate it. > > Thanks. > > TTFN - Guy >
SMD disk specifications
Hi, I’ve been trying to find *detailed* specifications (mainly detailed signal timings) for the SMD disk interface but all I’ve found so far are the interface specifications for individual disks (CDC, Fujitsu, etc). I’ve looked in the usual places (bitsavers mostly) and haven’t found the spec itself. If anyone has any pointers, I’d appreciate it. Thanks. TTFN - Guy
