1771 floppy controller questions

Yeah ... I wasn't sure about that, though I know they sold their

version of the WD HDC chips (1010 and 2010). Didn't NEC also make a uPD371 that was for small tape drives? I know they

something on that order, but I never got to play with them. Dick ----- Original Message ----- From: "Allison" <ajp166(a)bellatlantic.net> To: <classiccmp(a)classiccmp.org> Sent: Tuesday, November 20, 2001 10:56 AM Subject: Re: 1771 floppy controller questions > Intel never did a 1771 compatable chip. They did do the 8271 that was > FM only but totally incompatable with the 1771 socket. > > The second source that did ship parts is SMC. The other supplier was > National Semi. > > NEC Started with the D372, that was a hard/soft sector single density > controller that did find it's way into the first version of the IMSAI

> controller. > > Allison > > -----Original Message----- > From: Richard Erlacher <edick(a)idcomm.com> > To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> > Date: Tuesday, November 20, 2001 12:05 PM > Subject: Re: 1771 floppy controller questions > > > >I don't know right offhand of any second sources, except for Intel,

> did, > >IIRC, make a 1771-equivalent/compatible for a time. They went the NEC > route > >when MFM became popular, however. > > > >WD also made a 1781 which was M2FM capable, and, as some folks will tell > you, > >THAT's a hard modulation scheme to support. > > > >As I mentioned before, it might be worthwhile to communicate with Tony > Duell > >regarding the expansion interface, as he recently admitted he'd actually > made > >the model-1 disk interface work as it was designed to work. A lot of > folks > >couldn't get reasonable reliability until they bought a third-party > enhancment > >for the floppy interface. > > > >Dick > > > >----- Original Message ----- > >From: "Tothwolf" <tothwolf(a)concentric.net> > >To: <classiccmp(a)classiccmp.org> > >Sent: Tuesday, November 20, 2001 8:51 AM > >Subject: Re: 1771 floppy controller questions > > > > > >> On Tue, 20 Nov 2001, Richard Erlacher wrote: > >> > From: "Tothwolf" <tothwolf(a)concentric.net> > >> > > On Tue, 20 Nov 2001, Richard Erlacher wrote: > >> > > > >> > > > What is it that makes you believe that the 1771 s the problem? > >> > > > >> > > Well, I accidentally plugged the chip in backward when > troubleshooting the > >> > > floppy interface right after I got it. It turned out that the

> >> > > ribbon was bad, just due to age I guess. I don't think the chip

> out > >> > > its magic smoke, but it certainly does not work now ;) > >> > > >> > OK ... I can believe you'd reach that conclusion from what you > describe. > >I've > >> > done that on one of those "late nights" on more than one occasion. > It's > >> > reasonable to assume the part is toast, given that there are several > >supplies, > >> > each of which has been applied to the wrong pins. Too bad ... > >> > >> I'm really not too worried about it, since the 1771 does seem to be > >> available and I have the technical reference book for the expansion > >> interface. I don't think there are any unusual or proprietary chips

> >> in the expansion interface with the exception of the floppy

> If > >> it took out any other logic chips with it, I should be able to replace > >> those easily. > >> > >> It appears that my local vendor may have just assumed the part he has

> >> stock is a National, since I can't find any references to National