12 Oct
1999
12 Oct
'99
3:20 p.m.
<> 48tpi single sided (sa400)
<> 48tpi double sided (sa450)
<> 96tpi single sided (teac Fd55E or DEC RX50)
<> 96tpi double sided (teac FD55F)
<> 100tpi single and double sided models (micropolis I think)
<>
<
<Ok, I wasn't aware of any 96tpi drives except the HD ones... Were
<they ever used in the PC marketplace, or was it mostly a DEC thing?
<After re-reading my uVAX manual about the RX50, I agree it is a
In the PC market place... what that? ;) Ok, No. PCs used 48tpi and the
later 96tpi/all mode (fd55gfv or similar).
Most of the 96tpi drives known as QD were in the CPM/CCdos/Zdos market
and were DD rate but double storage due to twice the tracks of the 48 tpi
drives (hence quad density). The same format that gave 360k on a 48tpi
two sided drive allowed 720k on a QD drive by virtue of more tracks.
<96tpi single sided drive, though the manual says: "Use only formatted
<RX50 diskettes, available from DIGITAL or its licensed distributors"
RX50 is not a media problem it's a formatting problem as it's 10 512byte
sectors per track and the 1793 (and kin) really are the correct parts to
exactly duplicate that format. Most PCs can with the right drive format
RX50 media (teac FD55E or 55F with correct jumpers in place).
RX50 media is standard two sided DD
media. I use it for RX180 and also RX180 for RX50 properly erased and
formatted and both work in PCs as 360k media (erased and formatted).
<RX50 360K,96tpi,80tracks/side
<???? 720K,96tpi,80tracks/side - What was (is) this called? DSQD?
Yep! It was used in many machines but most were CPM based or PCdos
not on standard PC hardware( or CCdos on S100).
<DSHD 1.2M,96tpi,80tracks/side - can read older media, but writing
< is unreliable (head isn't wide
< enough to erase the whole old track)
Correct.
<If Bill indeed has DSDD media, bulk erasing the media before applying
<it to the 96tpi (non-HD) drive should work fine. This erases the old
<data from between the new (half as wide) tracks, so it doesn't
<interfere with reading.
Correct.
In the 5.25" drive market from 1977 to current the number and variation of
drives and controllers and formats used would make one batty. there were
for the most part only a few differnt media though. Most of the media with
the exception of 1.2mb (or it's derivitives) was all the same oxide and
any variation was hard sector, odd envelopes or only one side certified
good (though both were usually good.).
FYI: I have NON-PC 5.25 media for:
old 35track sa400s (verbatum and shugart) hard and soft sector
(inclued the originals for my NS* system that have short window
and the ICOM FDOS soft sector media with short window)
Visual 1050 96tpi 1 and two sided variations. <FD55F and 55G>
RX180 <sa400l and tandon TM100-1>
RX50 (vms, POS, RT11, Rainbow, RSX, Netbsd, XXDP, OS8, WPS
filesystems) <rx50>
RX33 (dec 1.2m for Vaxmate and Later vaxen) <FD55GFV>
Ti99/4 (40tr SSSD) <sa440L>
H89 softsector <tm100-1>
Kaypro (SSDD, DSDD, DSQD advent turborom format) <mix of drives>
Ampro 48tpi and 96tpi CPM <I used FD55B 48tpi early on>
And a box of misc mongrul formats.
Those are the ones in active use here. I've endevored to reduce the
number of formats to those. PCs I unilaterally have discontinued active
5.25 media use as it's inconsistant at best and 3.5" is supported in most
I use (I have one system that can do 360, 1.2 or ?? if need be).
Allison