24 Jul
2001
24 Jul
'01
10 a.m.
It was, IIRC, necessary to have a version of the RWTS (read/write track/sector)
routines for any block I/O device, and that is probably part of what the ROM
provided. I have a homebrew system that was certainly equipped with an RWTS
equivalent so that it could read APEX-formatted 8" diskettes (APEX being a
locally generated OS for the APPLE, that used 8" diskettes via the Sorrento
Valley Associates 1771-based controller on an APPLE) by means of my hand-wired
interface and an SMS FT400 controller with 2 8" drives. It was even MFM
capable, which the Apple-based SVA adapter was not, though I read that SVA was
planning to release a DD version.
If you could patch the resident OS to determine which controller was needed and
to select the appropriate RWTS version, (think of this as BIOS primitives) then
return the appropriate values when it was done, it would happily work with the
Apple. While WOZ's FDC and FDD were designed to save APPLE lots of dough, they
didn't give away much, and they didnt' cause lots of software problems. The guy
did some fine work.
Dick
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Tuesday, July 24, 2001 12:37 PM
Subject: Re: Apple ][ boards -- what have I found?
On Mon, 23 Jul 2001 23:58:49 +0100 (BST), Tony Duell wrote:
#> > I wonder if the 'Cold Boot Adapter' links to that KONAN card and
adds
#> > a hard disk to the Apple. The Cold Boot part meaning the Apple can
#> > boot from the hard disk without needed a boot floppy. I am
probably
#> > wildly off, though
#>
#> I was thinking something similar actually.
#
#In which case I should start looking at the EPROMs on these boards).
This seems unlikely. Apple IIs never needed a boot floppy, they just
booted from the first recognizable disk controller, starting at slot 7
For an Apple to boot from a disk controller (any disk controller), there
has to be code in ROM on the disk controller that tells the Apple's CPU
how to read the boot sector, etc. That's what one of the PROMs on the
Disk II card is. After all, you can't expect the Apple monitor ROM to
understnad every disk controller that ever could exist.
If you have a disk controller _without_ such a ROM, then you'd need a
program (presumably loaded from a disk via a normal Disk II controller)
to use it. I've seen a 1771-based card (to read 8" CP/M floppies) that
did this. The Apple couldn't boot from it, but you could run a program
from a normal disk to copy files between normal Apple ][ disks and the 8"
CP/M ones.
If this cold boot adapter is to do with the hard disk, then it's possible
that the ROM contains the boot code so the machine can boot from the hard
disk. I have no idea if there's a similar card without the ROM that
needs a boot floppy.
-tony