graham@dolmen.UUCP (James Graham) (09/07/90)
>In article <4302@crash.cts.com> oleg@crash.cts.com (Oleg Rovner) writes: >I know this subject came up before, but I didn't save the thread, and now >I'm desperately in need of info, so please help. (Gawd, I sound like a >Televangelist :-) > >My external drive (an original 1010 from 1985) just ate it, or more properly >the drive mechanism did. Now, I was wondering if I could take a 720k IBM >drive mechanism that I have laying around and plug it in. So I did. It >doesn't work. The mechanism is plugged in place of the old drive mechanism >(ie the 1010 case/ic board) and I get two? problems, 1. No formatting (the >drive DF1: is BAD on bootup, formatting doesn't work, aborts with the >no sector header error on track 0) 2. Media change detection doesn't work. > >The drive model is Toshiba ND-3521GR, if someone could point me toward a >solution, or better yet, provvide one, I'll be eternally grateful. I'm presently using a Toshiba drive as DF1: on my system. To interface it, I tried two things. I read the tech manual and came up with a "prototype" interface, which consisted all of two IC's. If I recall, a 7474 ttl quad d-flipflop and a 7417 open-collector hex inverter. The important part is to get the Amiga to recognize the IBM drive as an AMIGA drive....hence the additional IC's. The amiga, during boot, expects a series of 1's and 0's from a single line on the external drive connector. The sequence of these bits determines what kind of drive is connected (sort of an ID code). That interface worked, but I experienced an occasional trashed floppy, probably due to flaky wiring or something to that effect. I was fortunate to have a friend who came across a dead amiga external drive. Since the heads were destroyed, the interface was intact. He gave me the interface and cable, and I made the pin translation between the drives, connected the interface to the Toshiba, and off it went. To this day I have had no problems. I tried two things to overcome the media change detection problem. First, I found the microswitch (in the Toshiba) that served as a disk inserted detector to the Toshibas internal circuitry (unfortunately, this was not brought out to the edge connector). I ran a wire from this, to the appropriate pin on my "home-built" interface and it half-way worked. When I installed the commercial interface, I simply connected a toggle switch between ground and the diskchange line on the amigas external connector. This was livable, but I got tired of flipping the switch and at other times, forgetting and experiencing gurus as a result. So, I found a pd program called "dc", which was compiled with drive df2: in mind. I modified the source for df1:, changed the graphics images to reflect the same, and recompiled. This way, there was an icon on the workbench screen that I could click when I changed disks. Anyway, I no longer have the drive connected since I now have a hard disk. If you are interested in my "prototype", let me know your smail address and I'll see if I can find the old drawings and send you a copy. I don't recommend it, however, because of the infrequent disk-trashing problem. -- ___________________________________________________________________ | **** JUST A REMINDER ***** | |"That to secure these rights, governments are instituted among men,| |deriving their just powers from the CONSENT OF THE GOVERNED. That | _|whenever any form of government becomes destructive to these ends, | | |IT IS THE RIGHT OF THE PEOPLE TO ALTER OR TO ABOLISH IT..." | | | (emphasis added) -- T. Jefferson, et al | | |___________________________________________________________________| |dolmen!graham@iuvax.cs.indiana.edu | Wow! Windows on |The Portal Dolmen BBS (812)334-0418, 24 hrs. daily|<- UUCP News!!!! |__________________________________________________|
oleg@crash.cts.com (Oleg Rovner) (09/08/90)
I know this subject came up before, but I didn't save the thread, and now
I'm desperately in need of info, so please help. (Gawd, I sound like a
Televangelist :-)
My external drive (an original 1010 from 1985) just ate it, or more properly
the drive mechanism did. Now, I was wondering if I could take a 720k IBM
drive mechanism that I have laying around and plug it in. So I did. It
doesn't work. The mechanism is plugged in place of the old drive mechanism
(ie the 1010 case/ic board) and I get two? problems, 1. No formatting (the
drive DF1: is BAD on bootup, formatting doesn't work, aborts with the
no sector header error on track 0) 2. Media change detection doesn't work.
The drive model is Toshiba ND-3521GR, if someone could point me toward a
solution, or better yet, provvide one, I'll be eternally grateful.
Regards,
OR
contents copyright (c) 1990 Oleg Rovner and may not be quoted and/or
distributed without permission except by/on USENET and /dev/null
**********************************************************************
"How did these teenagers learn how to make such bombs? It was easy for
them! They learned everything they had to know from computer
programs." -Baltimore area TV news, quoted on rec.pyrotechnics
johnhlee@svax.cs.cornell.edu (Johnny H. Lee) (09/13/90)
In article <4302@crash.cts.com> oleg@crash.cts.com (Oleg Rovner) writes: [...] >My external drive (an original 1010 from 1985) just ate it, or more properly >the drive mechanism did. Now, I was wondering if I could take a 720k IBM >drive mechanism that I have laying around and plug it in. So I did. It >doesn't work. The mechanism is plugged in place of the old drive mechanism >(ie the 1010 case/ic board) and I get two? problems, 1. No formatting (the >drive DF1: is BAD on bootup, formatting doesn't work, aborts with the >no sector header error on track 0) 2. Media change detection doesn't work. > >The drive model is Toshiba ND-3521GR, if someone could point me toward a >solution, or better yet, provvide one, I'll be eternally grateful. > >Regards, > OR I've successfully interfaced three Toshiba drive to Amigas (one for my brother, my uncle, and myself) and they work great (one going on six months with no problems.) However Toshiba makes several different models with different abilities. Mine were series ND352, FDD4216. These are 720K drives with a diskchange and jumper-selectable RDY/diskchange signal. The interface boards I built basically latches the MOTORON signal which the Toshibas won't do. (Could be the cause of your problem #1. Plenty of schematics to do this are floating around.) You didn't give the FDD number (assuming you even have one.) Some of the other drives in this series with different FDD numbers (like 4202, 4206) won't work (no diskchange) but the FDD4210 will. I picked up the 4216's for $10 a piece at the ACP swapmeet in Orange County, CA from Jade Computers who were dumping some untested surplus pulls. I figured that I could piece together a working drive from the parts. But when I plugged them into my drive 1 spot in my 2000, surprise!, they all worked fine. Lucky I guess. If your drives don't generate the diskchange, you can: 1. Use the DISKCHANGE command. Not very appealing, but it works. 2. See if the drive actually has the circuitry, but is simply not enabled, perhaps because of a jumper. 3. Somehow wire-in your own switch and circuit to do it. This can be a bit tricky, but its not impossible. Good luck! ------------------------------------------------------------------------------- The crew goes in search of Leo! Next time on AmigaDos: The Next Generation. John Lee Internet: johnhlee@cs.cornell.edu The above opinions of those of the user, and not of this machine.
srm@dimacs.rutgers.edu (Scott R. Myers) (09/13/90)
I have a situation where I'm trying to revive an A1000 for use with
video stuff. One of my problems is finding an inexpensive storage
solution. I wouldn't mind building an external dual floppy setup if I
could get the cost in under say $150-$175. Is it difficult to do this
and are there any docs floating on the net to walk through such a
procedure? Any help would be appreciated. Thanx.
srm
--
Scott R. Myers
Snail: 26 Stiles Street Phone:(201)882-3100
Apartment 18
Elizabeth, NJ 07201
Arpa: srm@dimacs.rutgers.edu Uucp: ..!dimacs!srm
"... No matter where you go, there you are ..."