I just finished ironing the bugs out of my Rev0 project and I’d like to get a copy of DOS 3.2. I’m running 3.3 but I’d just like to get a copy of 3.2. All the images I’ve found are in a .d13 extension. I’m presuming this is 13 sector. Does anyone know where or even if I can find a dsk image of 3.2 that I can write with adtpro in a 16 sector drive? I haven’t tried but I don’t believe adtpro supports .d13 extensions.
Thanks group
How to make a 13 sector boot disk, se this thread:
https://www.applefritter.com/content/quick-disk-ii-1316-sector-question
Important:
In order to actually use/boot a DOS3.2 disk, you need to have a 13 sector disk controller card.
Without a 13 sector disk controller card you won't be able boot from the DOS3.2 disk and get DOS3.2 into memory.
Thank you for the reply. So without a 13 sector controller card and 13 sector drive I won’t be able to use 3.2. Not the end of the world, I just thought it could be done simpler than that. I’ll just stay with 3.3 I guess.
It's only the disk controller card that is different.
And it's actually the P5 and P6 prom on the card that is different. And it's the P5 prom that really matters.
So if you could get hold of a 13 sector P5 and P6 prom (part no. 341-0009 and 341-0010) you can put it on your existing disk controller card and it should work as a 13 sector disk controller card.
And it is actually only the P5 prom that is needed to be changed.
I think I read somewhere that the P6 is more or less the same for 13 and 16 sector.
Take this with a grain of salt, as I have never tried this.
Please note that I'm not sure if it's the P5 or P6 that is the boot loader prom, but it's the boot loader prom that is important (I could probably google it but I'm lazy).
But one thing is certain: the drive itself is the same for 13 and 16 sector disks.
I believe 4am's Anti-M utility will allow you to boot a 13 sector floppy or image on a 16 sector controller. I don't know if it will help you write out a 13 sector image to a disk. But should allow you to boot them. I believe it somehow patches the PROM in memory.
Tanks Nick. I didn't know about 4am's Anti-M. I will have to try it out.
There's also DoubleDOS (aka DubbleDOS) that will boot and work with both 13-sector and 16-sector disks. The software product, not the hardware board that switches PROMs. Just boot the disk; no hardware changes or requirements. Automatically switches between formats as necessary (with a simple "beep" to let you it switched!)
Correct. Apple modified both ROMs for 16-sectors, but the boot ROM is the one that enables you to boot 13-sector vs. 16-sector disks. The sequencer ROM contains a bug-fix that was necessary to read 16-sector disks; there's no benefit in reverting to the original (buggy) sequencer ROM.
James Sather explains the disk controller and all the differences between implementations for DOS 3.2 (13-sector) and DOS 3.3 (16-sector) in Chapter 9 of his book Understanding The Apple II. Archive.org has that whole book online for free reading at https://archive.org/details/understanding_the_apple_ii/page/n229/mode/2up?view=theater
If you want to switch freely between booting 13-sector vs 16-sector disks, hunt down a MicroSci A2 disk controller. It can boot from either format just by moving a jumper:
IMG_0674.JPG
QFT (quoted for truth):
I happened to get a Franklin Computer Disk Interface Card which also have jumpers for 13 and 16 sectors.
See https://www.applefritter.com/content/franklin-computer-disk-interface-card
Thanks everyone for all that. Sounds like I have a few options. I’ll research a few of them.
I've been told that the Franklin card design was licensed from MicroSci.
I remember using BOOT 13 from either the DOS 3.3 System Master or DOS 3.3 BASICs disk... I don't remmeber which. But it would let you boot up a 13 sector disk even if you had the 16 sector P5 and P6 PROMs on your Disk ][ Controller card if I remember right.
Googling it produced this link which is interesting...
https://llx.com/Neil/a2/better.boot13.html
There is a version of ADTPro that writes to 13-sector disks with "standard" 16-sector controller.
Also, as mentioned, BOOT13 is part of DOS 3.3 and works fine. You boot 3.3 first, then run BOOT13 and it asks you to insert a 13-sector disk and press a key to boot.
Oh yeah, I remember BOOT13 from way back and used it frequently after ugrading to DOS 3.3 PROMS and having many, many DOS3.2 formatted disks I needed to still use to migrate data off of.
Thanks for the reminder.
Just wanted to say this is a very insightful thread for us beginners and that I learned a lot reading all of you