jon@galadriel.bt.co.uk (Jon Hopkins) (05/24/91)
I have just upgraded my system from an A500 to an A3000/25/100. Everything workes fine except my external disc drive which is a combined 3.5 and 5.25" unit (the 5.25" drive appears to the Amiga as a 3.5" 880k drive). The 3000 does not recognise either drive. I have tried changing the drive select lines to work with units 2 & 3 instead of 1 & 2, since the sel1 line seems to be reserved for a second internal drive, but still no joy. The real question is what has changed between the 500 & 3000 in the way of drive timings, and could this affect the way the drive is recognised? (How is the drive recognised anyway???) The drive in question is made by Power Computing, if this is any help. If anyone has any ideas for circuits which actually work on A3000 this might help as well. Thanks in advance, Jon. ============================================================================ Email: Jon@galadriel.bt.co.uk Snail: British Telecom Research labs, Martlesham Heath, Ipswich, Suffolk, UK
jesup@cbmvax.commodore.com (Randell Jesup) (05/25/91)
In article <1991May24.084816.16737@galadriel.bt.co.uk> jon@galadriel.bt.co.uk (Jon Hopkins) writes: > >I have just upgraded my system from an A500 to an A3000/25/100. Everything >workes fine except my external disc drive which is a combined 3.5 and 5.25" >unit (the 5.25" drive appears to the Amiga as a 3.5" 880k drive). The 3000 >does not recognise either drive. I have tried changing the drive select >lines to work with units 2 & 3 instead of 1 & 2, since the sel1 line seems >to be reserved for a second internal drive, but still no joy. > >The real question is what has changed between the 500 & 3000 in the way of >drive timings, and could this affect the way the drive is recognised? >(How is the drive recognised anyway???) They have an ID that is read at boot time (normally). See the hardware manual for details. The A3000 is set up for two internal drives, whereas the A500 is set up for one. This should not affect a properly designed drive (just as an A1011 can plug into a A500 as df1: or a 2000/3000 as df2:). Beyond that, I can't say. There's been no change to the interface. If they were marginal they might be broken by faster changes on signals due to a faster processor (should not matter if they're designed to the right spec). -- Randell Jesup, Jack-of-quite-a-few-trades, Commodore Engineering. {uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.cbm.commodore.com BIX: rjesup Disclaimer: Nothing I say is anything other than my personal opinion. "No matter where you go, there you are." - Buckaroo Banzai