Reading SVI-328 floppies on PC?

Por mikko

Supporter (2)

Imagen del mikko

27-04-2010, 01:33

Hi, a new user asking noobie questions obviously...

I got my SVI-328 for Christmas 1984 when I was 5 years old. It was my only computer until 1991 and programmed quite a lot on it.

Now it would be quite nice to see those old programs again. I still have most of the floppies but the SVI floppy drive seems to be broken - it doesn't seem to close so it must be a broken spring or something like that. Can PC's read those old diskettes?

I know this must be answered somewhere but my google and forum search abilities must be a bit rusty.

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Por Rataplan

Master (214)

Imagen del Rataplan

27-04-2010, 10:05

I think you should be able to read them on a PC, as they followed the same standards imho. But IIRC the SVI floppy expansion was 5.25'', might be a bit harder these days to find a mathcing PC-drive. I still have a brand new one though Wink

Por MäSäXi

Paragon (1884)

Imagen del MäSäXi

28-04-2010, 10:34

Maybe you should check often every local (and near (even little) towns too) Kierrätyskeskus. (finnish term, a place where you can bring your old stuff, no matter is it electric stuff, furniture or clothes or toys, they will repair it and sell them with very low price.Smile) If you have any luck, they could have separate 5,25" PC disk drive (and maybe it´s cables too). Or put "will pick up/buy cheap 1980s PC with 5,25" disk drive" to local shops´ notice boards. Surely someone has 5,25" PC in the closet or attic.

Another idea could be to make conversion program which allows MSX to read SVI BASIC programs. (if you used only BASIC?) Mikrobitti´s "Huvia & Hyötyä MSX" book had that program, don´t remember thought was it tape only or did it read disk programs too?

Por jr

Champion (375)

Imagen del jr

28-04-2010, 12:14

I have a separate 5.25" HD disk drive lying around somewhere, it has no covers since it used to be an internal drive on a PC. Worked fine with DD/SD disks too. No idea if it is actually working still, it was powered and working last time some 15 or so years ago. If I remember correctly you could use the same cables as for the 3.5" PC drive back then but perhaps they are not the same anymore nowadays. I could try to find it and bring it to the msx info update 2010 for you if you really badly need it and have not found one until then, let me know.

Por mikko

Supporter (2)

Imagen del mikko

28-04-2010, 16:09

So an ordinary PC floppy drive will read the disks just fine? That's nice, I know a guy who kinda collects old computer stuff and he has a fully functional computer with a floppy drive.

Por MäSäXi

Paragon (1884)

Imagen del MäSäXi

30-04-2010, 08:07

Please let us know, if PC can read your disks. Smile

Por gargamel

Expert (101)

Imagen del gargamel

30-04-2010, 08:29

If you have the possibility to use MS-DOS, I recommend ImageDisk which gives you more detailed information and it also analysis the disk format.
http://www.classiccmp.org/dunfield/img/

The first track on the first side is formatted with FM (18 sectors, 128 bytes) and the rest with MFM (17 sectors, 256 bytes). That applies to both single (SVI-902/605A) and double sided drives (SVI-605B). There were also an 80 track single sided drive available, SVI-912, but that was not a popular drive.

There's usually no problem reading the FM track in a PC, writing depends on your floppy controller chip, you can always skip that track because the first 3 are normally system tracks.

Start up IMD and configure the drive, the program detects the format for each track but to help it by settings would be:

- Cylinders 40
- Sides 2 for the SVI-605B, otherwise 1
- Double-step On for a HD drive, otherwise Off

For reading/writing problems with the first track (FM formatted), choose eXclusion map and toggle track 0 for first side only (down arrow symbol).

There's also a couple tools for converting the special disk image type to a format with sector data only. For example:

IMDU filein.IMD fileout.DSK /B

BIN2IMD filein.DSK fileout.IMD 328SS.B2I
BIN2IMD filein.DSK fileout.IMD 328DS.B2I /2

Here are the two option files used in the last conversion.

;
; Filename: 328SS.B2I
;
; Specravideo SVI-328 5.25" 40 track SS DD option file
; Usage: BIN2IMD filein.DSK fileout.IMD 328SS.B2I
;
0 N=40 DM=2 SS=128 SM=1-18 /1
1 DM=5 SS=256 SM=1-17 /1

;
; Filename: 328DS.B2I
;
; Specravideo SVI-328 5.25" 40 track DS DD option file
; Usage: BIN2IMD filein.DSK fileout.IMD 328DS.B2I /2
;
0 N=40 DM0=2 SS0=128 SM0=1-18 DM1=5 SS1=256 SM1=1-17
1 DM=5 SS=256 SM=1-17