On 2 May 99 at 23:49, Tony Duell wrote:
> > It's mounted in a standard labeled C64 1541 case. Everything else is stripped
> > out. Obviously a kit. The 20 pin connector is connected to a small 1 1/2" by
> > 3 1/2 ' board which supplies power, control and data connections to the bare
> > drive. The drive has the Apple latch and an activity lite. The only identifying
> > mark is FDC525 which is obvious. There are 4 mounted chips, the most
> > significant an 18pin MC 3470P 8237.
>
>
> A 3740 is a well-known read amplifier, etc, for floppy drives. It was
> used on a lot of 5.25" units.
>
> I've just dug out the schematic of the Apple Disk II and it uses a 3740
> as the read amplifier. The other obvious chips are a CA3146 transistor
> array (write driver), a ULN2003 (stepper driver, etc) and a 74LS125
> (3-state buffer). Do those match up with the ones in your unit?
>
> -tony
>
BINGO ! The only variance is a CA3086 instead of a 3146.
I just checked a "parts" Disk ll and it has your line up. The card is much
bigger tho and also has the Apple logo Disk ll analogue card marking.
So it would seem to be a 1/2 ht. Disk ll in a 1541 case. I was hoping for
something more exotic, but wha' tha' hell.
Thanks Tony
ciao larry
lwalker_at_interlog.com
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Received on Sun May 02 1999 - 21:48:55 BST