Talk:High density floppy disc access
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Why the 7.38 µs case isn't so impossible
request |
svc time :
clock |....5....0:...5....
12 c.Bc1da.ClIn <-miss
13 Sta.BC2da.ClI
14 nSta.Bc3da.ClI
14 nSta.Bc4da.ClI
14 nSta.Bc5da.ClI
14 nSta.Bc6da.ClI
15 nSta.Bc7da.ClIn
15 Sta.Bc8da.ClInS
15 ta.Bc9da.ClInSt
15 a.BcAda.ClInSta
16 .BcBda.ClInSta.B <-say the sector ends here
20+ cCda.ClInSta.BsBsBsB
-- beardo 23:41, 25 July 2009 (UTC)
Bit of a bish
I forgot that STA abs,X always takes 5 cycles. This increases the QD access interval to 7.88 µs (still fast enough for the nominal rate) and threatens stack balanced NMIs saving to 1 MHz addresses. Hope I can still guarantee correctness... :( – beardo 20:27, 11 August 2009 (UTC)
Page title and content wrong
It's not quad density, it's high density. Quad density is 2.88M on a DOS disk.
- Single density -> 400K FM/360K FM
- Double density -> 640K MFM/720K MFM/800K MFM
- High density -> 1280K MFM/1440K MFM/1600K MFM
- Quad density -> 2560K MFM/2880K MFM/3200K MFM
Jgharston 12:28, 17 October 2010 (UTC)
Moderation required: Insufficient time allowed for discussion
Quad density and high density are essentially the same thing. Notice that you've got your quad density disks with eight times the capacity of a single density disk rather than the four the name suggests. Assuming double sided disks here are the corrected names:
- Single density -> 400K FM/360K FM
- Double density -> 640K MFM/720K MFM/800K MFM
- Quad density/High density -> 1280K MFM/1440K MFM/1600K MFM
- Octal density/Extended density -> 2560K MFM/2880K MFM/3200K MFM
In any case the pages and images were renamed only 2 minutes after your post. As you did not allow any time for meaningful discussion and regardless of what decision is reached after discussion please revert your changes now so that I don't have to.
Jon Ripley 13:33, 17 October 2010 (UTC)
- High density is the better-known term, the moves are fine by me, for one. -- beardo 13:53, 19 October 2010 (UTC)
