Date: Thu, 1 Jun 1995 19:21:27 +0059 (EDT)
Subject: Re: How to format DOS hard disks for a PDP-11
From: Roger N Wallace

Cc: Info-PDP11@transarc.com

In-Reply-To: <3ql7vn$qgv@charm.magnus.acs.ohio-state.edu>

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Status: OR







On 1 Jun 1995, Michael C Comerford wrote:



>

> Is it possible to reformat a DOS-formatted Seagate ST-251 (equivalent to

> an RD32A drive) to be able to use it on a PDP-11/53, running RSX-11M+ ? Our old

> RD32A died and we have several ST-251s begging to be used.

>

> I'm interested in knowing if there are utilities included in the system,

> or freeware, or anything that performs the above operation. Thanks,

>

>

> mike c.

> Microprobe Lab

>

>

> ==============================================================================

> mike comerford comerford.1@osu.edu

> dept. of geological sciences (614) 292-1987

> ohio state university

>



The XXDP+ diagnostic kit, which is usually included with DEC-integrated

systems, should include the ZRQCH0.BIC format program. This will do the

necessary low-level formatting with an RQDX3 controller. Drive ID

should be set to "3" for the first and "4" for the second hard disk in

a BA23-series cabinet [common for 11-53's], rather than "1" as is typical

for PC's. Defaults should be OK for the other jumper settings. Follow the

menu for the RD32, and be sure to answer "Yes" to the "Continue if

manufacturer's bad block data unavailable?" question -- the PC drive

will _not_ have a DEC-style bad-block replacement table. Third-party

controllers, e.g. Webster, Sigma, often have low-level format routines

resident in firmware which are appropriate if the drive is to be run on

such a controller.



Once low-level format is complete, volume initialization is performed within

the operating system (the "DUP" program in RT11, not sure about RSX).



I believe that the integrated controller in a VAXStation 2000 can also be

used to perform an RQDX3-compatible low-level format, given the correct

VAX maintenance software. This is a bit more involved procedure, as the

disk must be moved to a PDP for initialization after formatting.



Incidentally, the ST-277R RLL variant of the ST-251 will also format

perfectly well as an "RD32". (But _not_ the ST-277N SCSI version!)



An RX50 diskette containing only the XXDP formatters used to be available as

a separate item from DEC -- price was about $80 as I recall; I can dig up the

part number and current price buying the diskette is an option.



Roger Wallace