IIgs using hard disk 20

From: r. 'bear' stricklin <red_at_bears.org>
Date: Tue Oct 16 17:51:38 2001

On Tue, 16 Oct 2001, Ethan Dicks wrote:

> > Nope, it's a 19 pin D-sub, which makes it physically compatible with the
> > NeXT monochrome display connector. Don't plug a Macintosh floppy drive
> > into the NeXT though, unless you want to start a fire. (;
>
> Is this the voice of experience?

Oh, good heavens, no. I can't imagine what anybody might think to
accomplish by doing so...

> Which lights up, the NeXT or the floppy drive?

It'd be the NeXT, since the drive would short out (via signal ground) the
+12V rail, the -12V rail, the pixel clock, and one of the lower speed
digital output ports. I don't think it would be a very happy situation for
the NeXT, though the floppy drive could conceivably escape with minimal
damage.

Since I'm at it...

    NeXT Monitor Macintosh External Disk Drive
    ------------ -----------------------------
1. +12 V Signal Ground
2. -12 V Signal Ground
3. Clock Signal Ground
4. Data Out Signal Ground
5. Data In -12 V
6. Power Switch + 5 V
7. NC +12 V
8. Vertical Sync +12 V
9. Horizontal Sync NC
10. Analogue Video PWM (motor speed control)
11. +12 V PH0 (command control line)
12. -12 V PH1 (command control line)
13. Signal Ground PH2 (command control line)
14. Signal Ground PH3 (command control line)
15. Signal Ground WRREQ/ (write request)
16. Signal Ground HDSEL (head select)
17. Signal Ground ENBL2/ (read line enable)
18. Signal Ground RD (read data)
19. Signal Ground WR (write data)

So obviously PWM has no meaning for systems which use the 1.4 MB
SuperDrive. On the Classic, this line was rerouted to the so-called
"analogue board", where it was used to implement the software brightness
control.

ok
r.
Received on Tue Oct 16 2001 - 17:51:38 BST