Re: Did Commodore cheat with the quad density floppies?

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Tue, 8 Jan 2019 18:32:08 +0100 Message-ID: <03dd1a69-a88d-35cb-d393-2dc41777406c@laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 1/8/19 6:19 PM, Mia Magnusson wrote:
> The questionable thing is really that the lines have pull-up. In Amiga
> 600, 1200 and 4000 commodore did solve this by instead having pull-down
> on the interrupt line in the IDE interface. (IDE is basically a
> stripped down ISA bus with two I/O address spaces decoded to two select
> lines. The timing and how all signals work is straight forward ISA on
> IDE).

I know, back then there were very cheap IDE cards for ISA where they 
even omitted the bus buffers, effectively the IDE cable was connected 
directly to the ISA signals.

 From the software side, IDE behaved like a WD1003.

  Gerrit