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Stealth Ian

Hans, I bought one of the F48's Ian has on eBay, and I hope to be able to set aside time to work on the LS-DOS autoboot.

There are two approaches I can think of:
1.) Cylinder 0 in the image gets reformatted to 512 bytes per sector, and a boot track gets written that can read the remainder in from the rest of the disk. Rest of the disk, starting at cylinder 1, is formatted 256 bytes per sector LS-DOS native. Use standard driver.

2.) Write a 512byte per sector driver for LS-DOS, and have a single format compatible with the other Model II HD OSes. Still need to write a boot track, but know how to do that, containing the Model II's boot signature. 512-byte sectors are required for HD boot on Model II.
 
@Iowen.

Some things to keep in mind when using the F48
The F48 can not execute a FORMAT command it is not implemented.
Sometimes the auto expand of the firmware of the F48 doesn't work good.
Use my MakeVHD 1.7 to create a ready made fully expanded VHD image.
Use hard4-0 for the first VHD, F48 is only looking for this drive.
If you need more VHD's copy hard4-0 to hard4-1 etc. they are automatically loaded.
If you want, I could try to make and option in MakeVHD to create a VHD with track 0 with 512 bytes sectors (17) and all the rest with 256 bytes sectors (34 or 32)
Use 2 or 4 Gb SD-cards they give the best results.
On the L2-631ds.imd in the repository you find the Misosys drivers for LS-Dos:

WD/DCT - device driver
WDFORMAT/CMD - formatter directory builder
WDHDBTIN/CMD - Initialize the bootsector on the VHD (Misosys says it doesn't work and would not work)
WDVERLOK/CMD - Very the system

Mathew Boytim has made LBA drivers for LDOS, they work and could be a starting point. Read about it in the article this year in TRS8BIT

Good luck

Hans.
 
Thanks for the good info, Hans. I was planning on using other tools to make the HD image, since I'm a little familiar with the F48 already. Hmm, an LBA driver? That's pretty cool.

I'm glad the double sided LS-DOS 6.3.1 disk I sent to Tim all those years ago has been useful. Back then I had three model 12 based chassis; a 12, a 16B, and a 6000. Out of nine or ten TM848 drives I only had one that would reliably write, and it had trouble after the machine warmed up. No nice floppy emulator boxen back then....
 
I was already working on a VHD file that uses two different sector sizes.
However, this is not possible for two reasons.
The algorithm that calculates the position in the VHD uses the number of sectors and the sector size.
It is obviously not possible to change one of the two parameters while working with the VHD.
No reference points are available in the VHD to determine the location in any other way.
Using only sectors of 512 bytes and using only the first half of each sector is also not possible because the
unused portion also counts towards the relative position determination.
I think it is only possible to work with a fixed value for sectors and include a link in the boot sector to more extensive boot information elsewhere on the VHD, for example at the end of the VHD
 
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