Apple ][ (clone) disk booting

[Dave Dunfield]

> What's the normal procedure to boot a floppy from an Apple ][? I'm just taking 
> a look at my Mitac [1] clone (with a view to selling it) and got curious as to 
> whether it'd boot a standard Apple DOS system disk.
> 
> If powered up with a drive connected the spindle motor starts and it'll step 
> the drive head back to track 0 - but nothing more.
> 
> On the one hand, it's entirely possible that the machine isn't a close enough 
> clone to work with standard Apple DOS (that wouldn't surprise me at all, in 
> fact) - but on the other, maybe I'm just missing some standard key combination 
> to magically boot from the drive... (whilst I've got an Apple ///, I've never 
> used an Apple ][ in my life)
> 
> I can hit CTRL-reset and the machine will drop to BASIC; is there a normal way 
> of booting (or at least bringing up a dir) a floppy from BASIC on a genuine ][?

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.

Normally, you will see the drive select and hear the head "rattle" against the stop
of a bit (Apple does not use a Track-0 sensor - it simply steps out 40 times no
matter what), then you head the drive seeking around as it loads the OS (Most
AppleII drives seek very smoothly, with a "swoosh" sound).

If you hit ctrl-reset it will interrupt the boot attempt and drop you to the
Apple basic prompt.

To re-try booting, you need to activate the disk controller ROM again, this is
easily accomplished with a PR# or IN# command referencing the disk controller
slot. The convention is to place the disk controller in slot-6, so the normal
way to reboot an AppleII is "PR#6"



--
dave06a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Collector of vintage computing equipment:
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