Re: Apple IIgs Virtual Hard Disk Project - Thoughts/Different Approach?

[BLuRry <brendan.robert@gmail.com>]

On Apr 29, 1:18 pm, IUnknown <stevement...@gmail.com> wrote:
> On Apr 29, 10:55 am, dog_...@macgui.com (D Finnigan) wrote:
>
> > IUnknown wrote:
>
> > > What would it take to get the IIgs to boot via the serial
> > > connection ... as cheaply as possible?
>
> > AppleTalk
>
> > --
> > Mac GUI Vault - A source for retro Apple II and Macintosh
> > computing.http://macgui.com/vault/
>
> If you can explain how to get the IIgs appletalk port to talk to a
> modern pc running mac/windows/linux without the need for additional
> hardware (router/bridge), I am all ears :)

The appletalk has the same pinout as the serial port.  I think I may
have misspoken though and meant to say the smartdisk port, not
appletalk.  The smartport connector looks like this:
Pin/Name/Description
1/GND/Ground
2/GND/Ground
3/GND/Ground
4/3.5Drive/3.5 or 5.25 drive select
5/-12v/Volt supply
6/+5v/Volt supply
7/+12v/Volt supply
8/+12v/Volt supply
9/DR2/Drive 2 select / extermal interrupt'
10/WRPROTECT/Write protect input
11/PH0/Motor phase 0 output
12/PH1/Motor phase 1 output
13/PH2/Motor phase 2 output
14/PH3/Motor phase 3 output
15/WREQ'/Write request
16/HDSEL/Head select
17/DR1'/Drive 1 select
18/RDDATA/Read data input
19/WDATA/Write data output

However, smartport doesn't use all of these (I'm sure you can ignore
the volt lines).  Judging by the packets of data, which spend 32
microseconds to send a byte, I estimate you need to to have a serial
port running at 250k baud, assuming it sends 8 bits per byte, no other
extra bits in between.  Using the RX/TX as well as the other status
lines, it may be possible to have enough data pins to act like a smart
port device over a serial connection.  Does anyone have good docs on
the the pin connections for smartport devices?  I have good logical
bus docs (including packet formats), but no details on the physical
hardware side.

-B