2 Oct
2007
2 Oct
'07
6:28 a.m.
Dave Dunfield wrote:
Hmm, I don't see the heads move (other than stepping to the outside track at
power-on if I've manually moved them) - no luck with PR#6 either (same
behaviour; starts the spindle motor, then briefly rattles the heads against
the end - outer - stop before just sitting there with the motor turning).
I'm going to take the machine in to the museum tomorrow though and try
combinations of different drives / media, as there's no way I can test here
that what I have is working.
What's the
normal procedure to boot a floppy from an Apple ][? I'm just taking
Powering it on should be enough to boot it. The apple launches the ROM on the disk
controller as part of it's initialization and that ROM tries to boot. If it's
booting at all, you should observe the disk head step all the way out, then back
in a bit as it reads the OS. If it just stays on the outside track, it's probably
not getting very far. (Most AppleII drives seek very smoothly, with a
"swoosh" sound).
This one's something of an unknown - it's a half-height drive in a case best
described as "borderline homebrew" (i.e. it's quite well done for something
done in a home workshop, but not quite as good as something I'd expect from a
professional product). No identifying marks as to who made it, but the drive
inside is made by ALPS - it's got a band-driven stepper motor for the heads
rather than the spiral groove that I seem to remember the disk ][ units having.
I'll dig out a genuine disk ][ drive tomorrow and see if that makes any
difference.
(The DOS disk I have is 3.2 incidentally... the wikipedia article on the A2
suggests there was a tweak available for genuine Disk ][ interface cards
post-3.2 to allow more sectors per track; I presume that such 'tweaked' cards
will still boot 3.2 and earlier media though? I've got no idea which 'type' of
interface this clone copies)
The convention is to place the disk controller in
slot-6, so the normal
way to reboot an AppleII is "PR#6"
PR#5 seems to activate the drive on this system too - weird. Hmm... if the
number following PR# is the slot, then I'll try this drive / disk combination
with a real Disk ][ interface card plugged into the Mitac's expansion
backplane (I've got a pile of Apple cards, I've just never had a genuine A2!).
Thanks for the info anyway - will see what I can find out tomorrow.
J.