SomeGuy
Veteran Member
So, I needed to stuff a tiny bit more data on a Prodos disk, and I recalled from some old experiments that the Laser 128 drives could do 40 tracks. I was well aware that the early Disk II full height systems used on II/II+/IIe computers only supported 35 tracks (well, technically they could get 36).
Wasn't sure about Apple IIc drives, but figured they had to be a bit more advanced, right? Nope.
Dug up an old hack that enabled 40 tracks on Prodos, applied that, and it formatted and verified a disk fine on a Laser 128 external drive attached to the IIc. Tried it on the IIc internal drive, and BZZZZZ. It didn't like that.
Not too surprised, but now that I am thinking about it, I'm wondering if that would have worked on any of the later unidisk models sold with later IIe or IIgs machines.
It still baffles my mind that even the last 5.25" drive apple cranked off of their assembly line with the IIgs machines were still only single sided, and never adapted to more than 35 tracks.
Heck, I recall once a long time ago having a generic Apple II clone drive that actually had two heads, but the second was unused. Apparently it was cheaper for some manufacture to just lobotomize an existing double sided drive. (Or a perhaps a creative way to reuse defective drives)
I have read about some other clone drives that did double sided or even quad density, and I think most half height clones did 40 tracks fine. But not Apple?
Wasn't sure about Apple IIc drives, but figured they had to be a bit more advanced, right? Nope.
Dug up an old hack that enabled 40 tracks on Prodos, applied that, and it formatted and verified a disk fine on a Laser 128 external drive attached to the IIc. Tried it on the IIc internal drive, and BZZZZZ. It didn't like that.
Not too surprised, but now that I am thinking about it, I'm wondering if that would have worked on any of the later unidisk models sold with later IIe or IIgs machines.
It still baffles my mind that even the last 5.25" drive apple cranked off of their assembly line with the IIgs machines were still only single sided, and never adapted to more than 35 tracks.
Heck, I recall once a long time ago having a generic Apple II clone drive that actually had two heads, but the second was unused. Apparently it was cheaper for some manufacture to just lobotomize an existing double sided drive. (Or a perhaps a creative way to reuse defective drives)
I have read about some other clone drives that did double sided or even quad density, and I think most half height clones did 40 tracks fine. But not Apple?