29 Jun
2001
29 Jun
'01
6:51 a.m.
I'm not sure I go along with that.
While it's advisable to check requirements before hooking up any device, I've
got to say I've never seen an 8" drive that used the "conventional" DC
supply
connector for 8" drives, as defined by the Shugart folks, et al back in the
'70's, that wouldn't work on precisely the same power configuration, using
+24,
+5, and -5 with the associated returns. While there were some drives that would
tolerate -12 in place of the -5 if you jumpered them approproately, I've not
seen any that would be damaged if you overlooked that detail and simply hooked
up -5. Moreover, the majority of drives available by the mid-80's, admittedly
late in the 8" drive's market life, didn't even require the negative
voltage.
Oddly enough, even the later 8" DC-powered drives from Shugart, Tandon, and
others, used that same connector for their DC supplies, though several of them
immediately regulated the +24 down to +12. NEC's DC-powered FD1165's, by the
way, were a noteable exception in that they used the same little connector for
power as the 3-1/2" drives use. That was why I gave away the ones that came
into my possession. I don't know what their DC power requirements were.
Dick
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Friday, June 29, 2001 10:16 AM
Subject: Re: WTB: 8" floppy
On Thu, 28 Jun 2001, Richard Erlacher wrote:
The power requirements are the same, i.e. the DC
supplies work for any
of them, though not all drives require the negative supply, but the
connectors for AC are often different for DS drives than for SS
drives. Siemens FD800-2's are notable exceptions.
NOT ALL 8" drives have the same power requirements!
Check the power requirements and pinouts CAREFULLY before connecting!
Drives WILL be damaged if you connect "connectors that fit" without
confirming that the drive uses the same voltages on the same pins.