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From: koziarz@halibut.nosc.mil (Walter A. Koziarz)
Newsgroups: comp.sys.zenith.z100
Subject: Re: 1.2MByte drives and Administrivia
Message-ID: <2114@nosc.NOSC.MIL>
Date: 10 Apr 90 22:12:10 GMT
References: <12577047218.9.GUBBINS@TOPS20.RADC.AF.MIL> <1864@cod.NOSC.MIL>
Sender: nobody@nosc.NOSC.MIL
Reply-To: koziarz@halibut.nosc.mil.UUCP (Walter A. Koziarz)
Organization: Naval Ocean Systems Center, San Diego
Lines: 36

In article <1864@cod.NOSC.MIL> sampson@cod.nosc.mil.UUCP (Charles H. Sampson) writes:
>

Please don't think me a 'prick with ears' but I *HAVE* to correct some
mis-information ---

>
>My dealer created something like this for me when I bought my Z-100 many years
>ago.  (I was certain that 400KB disks would be limiting.)  In the prices of
                           ^^^^^
at the time of the 192K motherboards, the floppies were 320K (360K when Z-DOS
was replaced by MS-DOS)

>those days the 4.77Mhz Z-100 with 192KB memory and the standard floppy drives
                ^^^^^^^
Nope, nope, nope there never was a 4.77MHz Z-100, that ridiculous clock rate
was an artifact of the I(nferior) B(ut) M(arketable) el-cheeeeeepo design
strategy.  Z-100's came initial in 5.0MHz and later 8.0MHz (the 8-bit side was
always 5.0MHz)

>
>The problem was that because the Z-100 thought it was working with 8" drives,
>they were powered up at all times and the heads wore through the surface of
>those disks at amazing speed.  It didn't show up when the dealer was experi-
>
Son-of-a-Gun, your dealer wasn't up on the *RIGHT* way to make the cable, the 8
inch controller's 'HEAD LOAD' should have been connected to the high-density
drive's 'MOTOR ON' line.  THIS would have performed proper motor on/off.

I hope this didn't sound too much like a flame; it WASN'T intended too.  I just
get like this when I see IBM-influenced miss-information (like the 'DOS 640K
BARRIER', etc).  Anyway, I am the happy user of a 2MB Z-100 (768K user RAM +
1256K of RAMDrives) AND a 1.2MB high density floppy, 8087, two 360KB floppies
and a 10MHz clock.

Walt K.