Re: Connector P2 on 2040/4040 mainboard?

From: Ethan Dicks <ethan.dicks_at_gmail.com>
Date: Tue, 18 Jun 2019 12:55:22 -0500
Message-ID: <CAALmim==Gn8zYXq_01OAY074VZAYjs8F6wYZTPVA21PnhcO6oQ_at_mail.gmail.com>
On Tue, Jun 18, 2019 at 12:35 PM André Fachat <afachat_at_gmx.de> wrote:
> I did some worl on these drives recently...
>
> I THINK you can just use the 8250 board as reference. It is a universal
> digital board and is supposed to be jumperable to 4040 mode.

Hi, Andre,

Good point.  Thanks for mentioning this.  I'll check those pages in a bit.

> As for the analog board you could cross compare the 2031 and 4040 and 8250
> analog boards, or even the apple ii disk ii board as they use the shugart
> sa390 as well.

I haven't looked at the 2031 schematics (I have a 2031LP but that's
just a 1540/1541 with an IEEE interface) so that's also something to
look into.

Apple, like Commodore, used the SA390 mechanism but used their own PCB
(with a 20-pin digital interface back to the Disk II card in the Apple
II) that connected to the raw 34-pin connector in the drive, like the
Commodore Analog board does.  At a functional circuit level, I'm sure
there are a lot of similarities between the Apple and Commodore analog
boards since the drive is the same.

I need to look into how the CBM digital board rolls the stepper lines
to see if it's easier to inject those directly into the Shugart analog
board (past the step/dir lines on its external 34-pin connector) or to
convert S0A/S1A/S0B/S1B  and -MTR 0 into Shugart interface signals
(step/dir and motor on)

Thanks,

-ethan
Received on 2020-05-29 21:57:55

Archive generated by hypermail 2.3.0.