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View Full Version : Juko XT drivers (relates to Samsung SPC-3000V, Faraday, Veridata TL-110, cdisk.sys)



AlexC
June 25th, 2015, 08:17 PM
Hi all,

When I was considerably younger I had a Samsung SPC-3000V, an XT machine with 640KB plus an extra 128KB of RAM that could only be used for a print spooler or RAMdisk. It had a Faraday chipset, and I think it might have been based on the Juko XT (ST?) board, since I've seen similar mention of that online, in fact in this very forum. I had a choice between loading spooler.exe or vrtdisk.sys to use that 128KB.

I now have a Veridata Turbolite TL-110 XT laptop that has a similar arrangement, and also uses a Faraday chipset. The BIOS counts to 640KB and then an extra 128KB of 'Expended' memory, as it calls it (though this can be disabled in the BIOS). MS-DOS of any version won't use this (ramdrive.sys, etc.) but DR-DOS vdisk.sys will see it and create a RAM drive. I can write data to it, and even read it back... but then a few minutes later it disappears and the RAM drive becomes corrupted.

Since this laptop can boot to DR-DOS from ROM, as well as from 1.44MB floppy, I'm wondering if the memory is mapped into the ROM address space, hence the destruction (and the option to disable the 128KB in the BIOS). But before I attempt to disable the ROM (the ramdrive would be more useful on a machine with no hard drive), I'd like to try the original drivers for the chipset, specifically the RAM drive.

From searching online the Juko one was called CDISK.SYS but I'm pretty sure the Samsung one was VRTDISK.SYS. I suspect either might work.

Can anyone help?

Cheers,
Alex

AlexC
July 3rd, 2015, 04:07 PM
Hi all,

Sorry to bump my own thread, but looking here it seems that this issue has cropped up before. For example here: http://www.vintage-computer.com/vcforum/showthread.php?12251-Use-of-ems-on-a-8088-xt/page4

where 'the XT guy' says "If anyone wants the juko driver, PM me."

Unfortunately that was in 2008 and I don't think he's still around. Does anyone else have a copy?

Thanks,
Alex

kpanic
July 31st, 2017, 11:13 AM
Hi AlexC,

Sorry to unearth this thread, but in your first post you mentioned the 'Expended Memory' can be disabled in the BIOS - But how?
I got a Veridata TurboLite 110 last year, and although it works, I don't have any documentation to this laptop. Is there a key-combo you have to press in order to get into BIOS setup? Or is there a tool you can run from floppy? Is there any possibility to change the settings in CONFIG.SYS and AUTOEXEC.BAT? The only thing I found out by myself is you can press 'F' to boot from floppy.

AlexC
August 1st, 2017, 11:31 PM
Hi AlexC,

Sorry to unearth this thread, but in your first post you mentioned the 'Expended Memory' can be disabled in the BIOS - But how?
I got a Veridata TurboLite 110 last year, and although it works, I don't have any documentation to this laptop. Is there a key-combo you have to press in order to get into BIOS setup? Or is there a tool you can run from floppy? Is there any possibility to change the settings in CONFIG.SYS and AUTOEXEC.BAT? The only thing I found out by myself is you can press 'F' to boot from floppy.

Ctrl-Alt-Esc gets into the BIOS at POST but I'm pretty sure the memory isn't useful on the ROM-DOS models as it's mapped over the ROM-DOS address space (I think). No, you can't change those config.sys and autoexec.bat settings, at least not without an EPROM programmer. If you search my threads on here you should find a more in-depth discussion of my attempts to achieve what you're trying to do. I eventually sold the laptop, but I think I was making progress.

alecv
August 2nd, 2017, 12:47 AM
AFAIK Juko ST was based on the V-Tech chipset, not a Faraday.
http://pcrebuilding.altervista.org/images/resized_my_pcrebuilding/56ea721801b84_p1100238.jpg
V-Tech chipset supported 128Kb of memory above 640K in uniq way, not as EMS.
There was a print spooler, disk cache and vdisk drivers for Juko ST and V-Tech chip.

Try JUKO from
http://wiki.sensi.org/download/ems_coll.arj

Xacalite
August 2nd, 2017, 05:26 PM
Neither Faraday nor V-Tech.
Juko ST boards are based on a Tamarack TD3300A chipset.
Access to the extra 384KB is via I/O ports, so no EMS page frame in the Upper Memory Area.
EMS is still possible, EMS driver does exist (I reckon it was written by one of the users of this forum), but it needs to steal 64KB from conventional memory for EMS page frame.