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From: link@stew.ssl.berkeley.edu (Richard Link)
Newsgroups: comp.sys.dec.micro
Subject: Re: "Standard" 360K floppies and the Rainbow
Message-ID: <13500@agate.BERKELEY.EDU>
Date: 20 Aug 88 04:21:30 GMT
References: 
Sender: usenet@agate.BERKELEY.EDU
Organization: University of California, Berkeley
Lines: 50

In article  GTHEALL@PENNDRLN.BITNET (George A. Theall) writes:
>
>    While others out there might want to confirm me on this, I
>don't believe it is possible to read "standard" (= IBM PC?) floppies
>with a Rainbow because of ***hardware*** limitations. That is,
>the RX50 drives in a Rainbow can only read one side of a disk;
>the "standard" 360K floppies are double-sided. No software program
>will be able to read a double-sided disk unless the hardware supports
>this.
>
Correct. The Rainbow has single-sided drives, so you can't read double
sided floppies.

You can read single-sided floppies formatted on an IBM PC.

You can also write to single-sided IBM floppies using a program called
MediaMaster which runs only on CP/M on the Rainbow. So first you have
to boot CP/M, run MediaMaster, and go through their menus to write
a Rainbow CP/M or MS-DOS disk to a single-sided IBM formatted disk.

MediaMaster WILL allow you to format a single-sided IBM disk using the
Rainbow drives. HOWEVER, I have sometimes (not all that often, but
enough to be a problem) found that my Zenith PC clone will not read
disks formatted on the Rainbow.

MediaMaster does state very clearly that this problem may sometimes
occur. Also, when actually using MediaMaster to format a single-
sided IBM disk, it gives a warning something like "formatting a 48
TPI disk using a 96 TPI drive". But it does usually work correctly.

I have found that it is a great inconvenience working in Rainbow
MS-DOS, writing to an MS-DOS disk, booting CP/M, and then 
writing the Rainbow MS-DOS disk to an IBM compatible 1S1D disk.

!!! The reason why this state of affairs is such is that DEC would
not give Intersecting Concepts (the publishers of MediaMaster) the
driver specs for using the 8088 to format the drives (or something
to that effect). Intersecting Concepts had to use the Z80 to do
the formatting, and hence CP/M.

I have not heard of using MEDIACHK to write to an IBM 1S1D disk.
Is this method reliable?

I find the easiest way to transfer data from my Rainbow to PC clone
is to kermit to/from my lab computer. Then I don't have to worry
about running out of room on a 180K disk.

Thanks, DEC!

Rick Link
link@ssl.berkeley.edu