rlw@ttardis.UUCP (Ron Wilson) (03/07/90)
In article <9221@stiatl.UUCP>, bgi@stiatl.UUCP (Brad Isley) writes: >In article <22605@pasteur.Berkeley.EDU> sjohn@cory.Berkeley.EDU (John Sasinowski) writes: >> I am interested in adding a 3.5" drive to my Unix PC to make >>backing up the hard disk easier. Jameco Electronics has a drive that >>is listed as a 720K drive for an IBM PC. Will this work in my machine? > >the sketchy requirements for making a 3.5" floppy work in the 3b1. If it's >configured for an IBM PeeCee it WILL NOT WORK. Sony's recent offerings in >the 3.5" size are hardwired for PeeCee compatibility - no jumpers. :-( >I know it won't work, I tried. Gotta have jumpers. I have a Mitsubishi in >mine. Works great. Stores 1560 blocks on a disk with a default file system. > >For the Mitsubishi, short the following jumpers: >SR MM IS DS0 >Also notice that you must twist the data cable when installing >Mitsubishi drives. It's very tight after the twist. > >For the Teac, short the following jumpers: >RY DS0 > >All jumpers not mentioned above must be open. >-- >Brad Isley, yer local tools blacksmith. Sounds good. Now, the next question: How about 2 floppy drives? (the 5.25 inch already there, plus, the 3.5 inch added on (externally, of course, but no problem for me)) Also, what about the high density 3.5 inch drives? - are these simply more tracks? or do they require more sectors per track? Thanks in advance. - Ron Wilson rlw@ttardis sharkey!cfctech!ttardis!rlw uunet!edsews.eds.com!rel!ttardis!rlw
bgi@stiatl.UUCP (Brad Isley) (03/08/90)
In article <2491@ttardis.UUCP> rlw@ttardis.UUCP (Ron Wilson) writes: >In article <9221@stiatl.UUCP>, bgi@stiatl.UUCP (Brad Isley) writes: >>In article <22605@pasteur.Berkeley.EDU> sjohn@cory.Berkeley.EDU (John Sasinowski) writes: >>> I am interested in adding a 3.5" drive to my Unix PC to make >>>backing up the hard disk easier. Jameco Electronics has a drive that ... >>the sketchy requirements for making a 3.5" floppy work in the 3b1. If it's ... [ notes on jumper settings... ] > >Sounds good. Now, the next question: > >How about 2 floppy drives? (the 5.25 inch already there, plus, the >3.5 inch added on (externally, of course, but no problem for me)) This I have no experience with except that I know you can plug in and unplug a floppy drive in a 3b1 all day and not cause any problems if the system isn't accessing the drive. This implies that you could get real sloppy and run the cables outside the case and plug in whatever you want to use at the time. Or you could be neat about it and connect both drives. One method of doing this would require two things: 1) one drive will be jumpered for drive select 1 instead of 0. 2) the installation of a switch in the cable between the motherboard and the drives. This switch would flip-flop the two drive select lines. Since the 3b1 only knows how to talk to one floppy (ds0 - or so I have heard!) you just flip the switch to the one you want to use. Any other similar switching scheme should work. >Also, what about the high density 3.5 inch drives? - are these simply >more tracks? or do they require more sectors per track? This also can be done. It requires a modification to the motherboard. You must replace a crystal controlling the floppy data rate (again, or so I have heard!) I haven't tried this one. I've just heard that it has been done. It's more of a one-way street. Do this and you can't read standard density. >Thanks in advance. No probs. -- Brad Isley, yer local tools blacksmith. --------------------------------------- What, me worry ?
mvadh@cbnews.ATT.COM (andrew.d.hay) (03/08/90)
In article <2491@ttardis.UUCP> rlw@ttardis.UUCP (Ron Wilson) writes:
[]
"Sounds good. Now, the next question:
"
"How about 2 floppy drives? (the 5.25 inch already there, plus, the
"3.5 inch added on (externally, of course, but no problem for me))
there is no drive select logic on the mother or in the driver.
fixing this will require a hardware hack and a loadable floppy driver.
"Also, what about the high density 3.5 inch drives? - are these simply
"more tracks? or do they require more sectors per track?
high density drives (both 3.5" & 5.25") double the data rate to get
more sectors per track.
fixing this will require a hardware hack and a loadable floppy driver.
...
i plan to look into hardware hacks in the course of my loadable floppy
tape driver...
"Thanks in advance.
you're welcome in advance.
--
Andrew Hay +------------------------------------------------------+
Ragged Individualist | But I thought we were *ALL* iconoclasts! |
AT&T-BL Ward Hill MA | I was just trying to fit in!!! |
a.d.hay@att.com +------------------------------------------------------+