Wtd: ESDI 3.5" hd + hd ?'s

From: jpero_at_cgo.wave.ca <(jpero_at_cgo.wave.ca)>
Date: Mon Jan 5 15:41:11 1998


> First off, though not quite 10 years, I'd love to find an affordable 3.5"
> ESDI hard drive in the 100-500mb range for my PS/2 model 70 lunchbox.
> Second, Does anyone know when the various hard drive interfaces were
> developed? The ones I can think of include:
> MFM (early 80's?)
> RLL (late 80's?)
> SCSI (late 70's?)
> ESDI (?)
If you're working at interfacing...

MFM and RLL is not a interface, ST506/512 is. This MFM/RLL is format
and encoding type. FM was started then leads to MFM way way
back around mid 70's I think, RLL was first developed by IBM and
started widespread use in mid 80's but not so numerous as MFM was.
SASI was around 70's roughly and begeat SCSI in early 80's. ESDI is
the answer to dinky, slow MFM for upping the performance and
capacity, reliablity and autoconfigure by Maxtor. MFM controllers
was made by WD for AT's and later this is later born as IDE chip
based on that and I still see this same chip in their WD's drives in
current production. WDC42C22A I think. Compaq was first to suggest
IDE idea and got WDC and Conner together in around 1985 then Conner
started shipping their IDE hd's in around 1986 because I *DO* have
that 1987 date on one OLD IDE conner hd. Also CDC / IMPRIMIS used
this IDE on several of their 5.25" drives as well about that time.

ATAPI is very late introduction to computing world in mid '90's
based on IDE.

Jaosn D.

> any others? Thanks...
> --------------------------------------------------------------------- O-
> Uncle Roger "There is pleasure pure in being mad
> roger_at_sinasohn.com that none but madmen know."
> Roger Louis Sinasohn & Associates
> San Francisco, California http://www.crl.com/~sinasohn/
Received on Mon Jan 05 1998 - 15:41:11 GMT

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