Ticket #43905

360K diskettes support

Open Date: 2022-02-19 01:17 Last Update: 2023-06-27 00:35

5 - Medium
5 - Medium


requested in 2021 by two SvarDOS users via the project's mailing list. Below I paste the initial answer I had given back then:

The first SvarDOS installation disk requires some basic tools and files to set itself up. These files can be grouped in 3 categories:

SYSTEM (kernel, format, fdisk, sys..) = 250K


USER TOOLS (edit, mem, more) = 100K

All this adds up to more than 360K. The only reasonable solution I see is to trim out "NLS" from the 360K install set. This means that the installer would be English-only (but it would still be possible to install the target system in another language).

It's also worth noting that a SvarDOS install set on 360K diskettes would take quite a lot of disks: a grand total of 9 floppies. (!)

I looked at it again today. Removing the following items from the startup diskette:

mdel -i disk1.img *.cpx

mdel -i disk1.img install.lng

mdel -i disk1.img display.exe

mdel -i disk1.img mode.com

mdel -i disk1.img edit.exe

I ended up with a diskette that has 295K on it.

This means it would be relatively easy to have a functional EN-only set for 360K computers. Such computers are probably unlikely to have an EGA+, so displaying anything non-US wouldn't be possible anyway.

How this would be implemented:

- build system must take care to remove the above files from the floppy template when building the 360K set

- installer looks for install.lng and if can't load it goes into "EN-only" mode

- one day, when we have a leaner replacement for edit.exe, it could land back on the 360K set (65K still available, should be enough for a basic editor, but not for FreeDOS edit which is 67K big)

Ticket History (3/14 Histories)

2022-02-19 01:17 Updated by: mateuszviste
  • New Ticket "360K diskettes support" created
2022-02-19 02:05 Updated by: mateuszviste

new problem: the COMMAND.SVP package is 580K big, so even alone it won't fit on a 360K floppy.

replacing FreeCOM by SvarCOM will solve this, since the SvarCOM package will be at least 10x smaller.

in the meantime I will strip the FreeCOM package so it does not contain any NLS in the 360K build.

2022-02-21 05:05 Updated by: None


A 360 KB image will be much appreciated! And a functional fdisk (0r simiaar) will be useful.

For example I want to use SvarDOS on a empty XT-IDE with compact flash card. But I have only a 360 kb floppy.

2022-02-21 05:26 Updated by: mateuszviste


The builds in the "files" section of the website have a 360K version, but without any guarantee. I announced it two days ago on the mailing list, let me paste the original message:

Some of you asked for a 360K build. I made it today (...) This build has one limitation: it is EN-only. I assume that if a machine has a 360K drive, it is unlikely to have a NLS-compatible video card (EGA+) anyway. And it allowed to reduce the set of 360K floppies from 9 to "only" 6 disks. That being said, I have no 360K drive or even diskettes, so I can't test this myself. I can only say that "it should work".

If you'd have the chance to test it, I'd really appreciate some feedback :)

Link to the "files" section: http://svardos.org/?p=files

2022-02-28 05:45 Updated by: None


Thanks for the images. Actually I am using an IBM 5160 with a VGA card and 360 kb floppy and also Amstrad 1640 with VGA card.

2022-02-28 05:53 Updated by: bttr
  • Owner Update from (None) to mateuszviste
2022-02-28 05:57 Updated by: bttr
  • Component Update from (None) to build.sh
2022-03-03 04:40 Updated by: bttr

Reply To (Anonymous)

Thanks for the images. Actually I am using an IBM 5160 with a VGA card and 360 kb floppy and also Amstrad 1640 with VGA card.

Would you please provide any feedback here or on the mailing list? :-)

2022-03-08 08:40 Updated by: None


I could not understand. Does this 360 kb version support VGA games?

2022-03-08 16:38 Updated by: mateuszviste

Reply To (Anonymous)

I could not understand. Does this 360 kb version support VGA games?

Hello, yes of course. The 360K version of SvarDOS is almost exactly the same as other versions. The only difference is that the installer is available in English only, due to size limitations.

2022-03-08 17:49 Updated by: bttr

Additionally: DOS programs either use video BIOS interrupt calls and/or write directly to video memory (= RAM on the video card mapped into the 1M address space) to support VGA, i.e., support for VGA games just depends on your PC's BIOS and VGA card. It does not depend on (Svar)DOS or disk size.

2022-03-10 03:52 Updated by: None

Is SvarDOS based on FreeDOS 1.3?

Is the first floppy disk enough to boot and execute the sys command ?


2022-03-10 04:42 Updated by: bttr

Reply To (Anonymous)

Is SvarDOS based on FreeDOS 1.3?

No. It's based on the packages listed (incl. version number) at http://www.svardos.org/?p=repo&cat=core

Is the first floppy disk enough to boot and execute the sys command ?

First floppy holds: SYS.COM, KERNEL.SYS, and COMMAND.COM. So, yes, disk 1 is enough.

(But at first, you probably have to create one primary partition on your HDD and format it. FDISK.EXE and FORMAT.EXE are also on disk 1.)

(Edited, 2022-03-10 04:42 Updated by: bttr)
2023-06-27 00:35 Updated by: mateuszviste
  • Status Update from Open to Closed
  • Resolution Update from None to Fixed

Closing this, since I have added 360K support back in February 2022. I tested it on a VM and it appears to be functional.

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