Re: How to transform a Disk II card to handle 13-sec?

[sicklittlemonkey <nick.westgate@gmail.com>]

On Feb 11, 10:38 am, Toinet <antoine.vig...@laposte.net> wrote:
> P5 13-sec again?

You can find out easily ...

First, in answer to David, P5 (P5A for DOS 3.3) is the boot code ROM,
and P6 (P6A for DOS 3.3) is the sequencer ROM.

As Vlad and David stated, a P6A will work fine with both versions of
DOS. The write portion of the P6A sequencer ROM is identical to P6 and
the read portion has basically been improved. In fact a P6 will still
work with DOS 3.3 too, but less reliably.

Since P5 is the boot ROM, the unit you have with the switch should be
usable in the P5/P5A socket on your disk controller card. With the
switch in each position (to be safe I'd power down before switching)
you can just list the ROM from the monitor with a C600L. If desired
you could compare them to the ones here:
http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/Disk%20Drive%20Controllers/Apple%20Disk%20II%20Interface%20Card/ROM%20Images/

> If I want a functioning set, I need to purchase and solder a switch,
> if the chip 341-0009 is well-placed, your thoughts?

The P5/A switch is all you need for the "ancestor experience." ;-)
BTW, someone posted here a few years ago about a controller they had
which would detect the 3.2 or 3.3 header and switch in the appropriate
bank for the boot ROM.

If you really want to verify the P6/A ROMS, then you can move them to
the P5 socket to read them from the C600 area, save the data, and
compare them to the dumped ROMs, or use Sather's disassembler to check
the contents. I think I have his program on a DSK if you want it.

Cheers,
Nick.