Date   : Tue, 27 Jul 2010 21:58:11 +0200
From   : rick@... (Rick Murray)
Subject: FileStore emulator - FDC

On 27/07/2010 20:58, Phill Harvey-Smith wrote:

> No but I have used the 2797 on the Dragon disk controler which is almost
> the same chip, infact it's also mostly software compatible with the 177x.

Yes, I see the datasheet says it is like the 1771. So I ought to look 
for a 1770 chip datasheet to see if some stuff is worded better...

Mmm, it is/isn't/is/isn't on bbcdocs.
Strange, there isn't one on nvg. Finally found one on a datasheet 
archive site, if anybody is interested, I have dropped a copy at:
   http://www.heyrick.co.uk/econet/fs/wd1770.pdf


> That seems valid, though I am supprised that it doesn't issue a reset
> command to the FDC, DragonDos does (as does OS-9).

Looking waaaay at the beginning of the log, it does:
--8<--------
      353377 &EC38 : FDC change: Test=No, MRst=No, DDen=Yes; FDC1=No, 
FDC2=No, Side=0
      353383 &EC3D : FDC change: Test=No, MRst=Yes, DDen=Yes; FDC1=No, 
FDC2=No, Side=0
      353494 &EC49 : FDC change: Test=No, MRst=No, DDen=Yes; FDC1=No, 
FDC2=No, Side=0
--8<--------


> has the advantage that it will handle a 500kHz data rate as used by both
> 8" disks

<giggle> Now that would be serious retro - a FileStore with dual 8" 
floppies.

We had a computer at school that was an integrated thing. Was a monitor 
with sideways disc drives to the right. Actually, it looked like a dumb 
terminal on any number of '70s movies, but it loaded software. Don't 
know anything about it, as it was kept in a locked room that I hardly 
ever went near (the Special Ed room).


> and 3.5" HD disks......

Did these even exist back then?



Thanks for the info.


Best wishes,

Rick.

-- 
Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...