On 07/14/2018 07:57 AM, Noel Chiappa via cctalk wrote:
> From: Jon Elson
> I THINK the 370/145 used the same drive.
The "IBM's 360 and Early 370 Systems" book doesn't say so explicitly (it just
says Minnow - the one with the solenoids - was a"incorporated in .. the
System/370 processo
> From: Jon Elson
> I THINK the 370/145 used the same drive.
The "IBM's 360 and Early 370 Systems" book doesn't say so explicitly (it just
says Minnow - the one with the solenoids - was a"incorporated in .. the
System/370 processors", pg. 517), but given that the follow-on drive
(Figaro/I
On 07/13/2018 01:04 PM, Tom Gardner via cctalk wrote:
Jon:
The 23FD used on most S/370 mainframes had a two solenoid and swash plate
actuator, pulse the in solenoid to go in and the out solenoid to go out.
IBM SJ in those days was very cost conscious and preferred mechanical parts
over electro
drive the stepper motor.
Tom
-Original Message-
From: Jon Elson [mailto:el...@pico-systems.com]
Sent: Thursday, July 12, 2018 6:41 PM
To: Paul Berger; gene...@ezwind.net; discuss...@ezwind.net:On-Topic and
Off-Topic Posts
Subject: Re: An historical nit about FDDs
On 07/12/2018 01:
On Wed, Jul 11, 2018 at 11:12:59AM -0700, Tom Gardner via cctalk wrote:
> Anyone know where the Step/Direction version of the FDD interface
> originated.
>
> So far as near as I can tell the earliest FDDs (IBM 23FD Minnow and Memorex
> 650/651) used Step In/Step Out. The IBM 33FD Igar used direct
On 07/12/2018 01:40 PM, Paul Berger via cctalk wrote:
IBM created the 8" diskette as an inexpensive and reliable
means of loading microcode and shipped the first read only
drives in 1971.
I am quite certain the original FDD on the 370/168 used a
pair of solenoid coils to ratchet the head in and
On 07/12/2018 11:40 AM, Paul Berger via cctalk wrote:
> Because IBM never sold the drives themselves and the market impact of
> the first Memorex drive may not have been really big, there was no real
> standard so when Shugart Associates released the SA800 its proved to be
> very popular and its i
[mailto:ccl...@sydex.com]
Sent: Wednesday, July 11, 2018 11:38 AM
To: Tom Gardner via cctalk
Subject: Re: An historical nit about FDDs
On 07/11/2018 11:12 AM, Tom Gardner via cctalk wrote:
Anyone know where the Step/Direction version of the FDD interface
originated.
So far as near as I can tell the earl
---
From: Chuck Guzis [mailto:ccl...@sydex.com]
Sent: Wednesday, July 11, 2018 11:38 AM
To: Tom Gardner via cctalk
Subject: Re: An historical nit about FDDs
On 07/11/2018 11:12 AM, Tom Gardner via cctalk wrote:
> Anyone know where the Step/Direction version of the FDD interface
> originated
> So far as near as I can tell the earliest FDDs (IBM 23FD Minnow and Memorex
> 650/651) used Step In/Step Out. The IBM 33FD Igar used direct control of the
> motor.
Someone asked (you?) on one of my Youtube videos for more detail about
the 23FD's stepping method, so I made a video covering the fi
On 07/11/2018 11:12 AM, Tom Gardner via cctalk wrote:
> Anyone know where the Step/Direction version of the FDD interface
> originated.
>
> So far as near as I can tell the earliest FDDs (IBM 23FD Minnow and Memorex
> 650/651) used Step In/Step Out. The IBM 33FD Igar used direct control of the
> m
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