Re: Did Commodore cheat with the quad density floppies?

From: André Fachat <*afachat_at_gmx.de*> Date: Fri, 04 Jan 2019 13:28:24 +0100 Message-ID: <16818d5fe40.27ff.b4d1f2b66006003a6acd9b1a7b71c3b1@gmx.de> · afachat_at_gmx.de

Am 4. Januar 2019 13:17:08 schrieb Gerrit Heitsch <gerrit@laosinh.s.bawue.de>:

> On 1/4/19 12:22 PM, silverdr@wfmh.org.pl wrote:
>>
>> Do you remember how the analogue section was solved there? All discrete or 
>> something like in 1541-II?
>
> The read amp seems to be an MC3470 in 18pin DIP. Not sure what they use
> for the write circuit, but there is a MC3346 next to the read amp which
> is a 'General purpose Transistor Array One Differentially connected Pair
> and three isolated Transistor Arrays'. Probably that plus some analogue
> tricks.
>
>  Gerrit

The MC3470 is BTW what Apple used in the Disk II anlogue board. So it has 
been around for awhile

André