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Minerva10210
January 26th, 2014, 09:15 AM
Hey guys

As some of you may have sen my previous question about the 486 laptop that I found at work, there was another item that I picked up.

This is a beige-box clone, with a NEC V20 in it, Juko - either mobo, or VGA card(16bit et400 - score ;) ), not sure which one's BIOS is actually showing the info. Then it has a ST11 controller card, and a KALOK Octagon HDD in it.

So there is a Multi-IO/FDD/RTC card in there, which actually supports 1.44 3.5" drives - and from what I can gather a 360K 5.25" and a 1.44 3.5 drive in it. So what I was trying to do is to get the machien to boot from the 1.44 drive, as the 360 drive's door actuator is broken. So I did the first thing, and that was to swop the A/B drives on the physical cable (hoping the keyed/swopped cable end) would signal to the controller card which is which. But alas, I think it is controlled via jumpers to tell the card which drive to expect on which end of the cable.

So, I have had a look on TULARC, and could not find anything on this card. the closes match was a MT811 - the card i have in question is a MT-8813.

Anyone seen one of these and could possibly shed some light on it?

Thanks!

http://i1220.photobucket.com/albums/dd453/Minerva10210/IMAG0056.jpg (http://s1220.photobucket.com/user/Minerva10210/media/IMAG0056.jpg.html)

dreadbit
January 30th, 2015, 10:25 AM
Hi,
sorry I cannot help you with what you exactly want to know - I've found this topic trying to find jumper settings for exactly the same board - did you found them? - but in your's case I'd tried to boot from a 720k formatted 3.5 disk with a closed HD detect (not Read protect!) window.
If that fails, I'd tried to
- close HD detect somehow
- format a disk as 720k
- write there an image on 360k disk there (on unix with 'dd' command) making it look like 40 track disk without double-stepping.
I'm absolutely sure that the method N2 should work, but that will be hard to read/write this sort of floppies on regular PC (but easy on linux, as I understand)

dreadbit
January 30th, 2015, 10:51 AM
..more, the thing I see is JP9 goes from of 74138 (which decodes A13 & A14 for 01,10,11 values) enabled by /MEMRD; that goes to NMC27C64N and is clearly is a BIOS extension enabler.
So there is BIOS. So, well, this card really *may* work natively with HD floppies.

dreadbit
January 30th, 2015, 11:51 AM
Got it!
JP9 - 2-3 - should run the card's native BIOS, you'll see "A: 360\nB: 1.44"
JP8 - Disk type. Remove jumpers for 2*1.44. Or play with them.

archeocomp
January 30th, 2015, 09:55 PM
JUKO is a MOBO. With V20 it is capable of 12MHz operation, with 8080 10MHz. Fastest I have ever seen. Could you pleas post link to MT811 on Tularc? I have this or very similar card somewhere too.

http://museum.ttrk.ee/th99/m/A-B/32279.htm

dreadbit
February 17th, 2015, 10:55 PM
JUKO is a MOBO.

Sorry if what I said was misunderstood.

What I said about jumpers was all about MT-8813 card, and more, I checked it myself. I tested it in ISA slot of P-I class system (Vectra 5), and that will be hard to test it in turboXT with NEC - I have one somewhere in wardrobe (but lazy to get it out of there and search for XT keyboard, while I even may have it around), but I'm sure it will behave the same way - just plug it into ISA and play with the mentioned jumpers.

Robin4
January 6th, 2016, 07:37 AM
I found a same card on ebay.. Iam waiting to arrive here..
If i have it i could help.. Also going to dump the ROM of the card and get it to minuszerodegrees website.

Do you maybe know the CR type of the battery of the RTC? I know this is an old style larger one, and not the one we nowdays use.

Robin4
January 6th, 2016, 07:43 AM
Got it!
JP9 - 2-3 - should run the card's native BIOS, you'll see "A: 360\nB: 1.44"
JP8 - Disk type. Remove jumpers for 2*1.44. Or play with them.


I think that JP9 is to set the Rom active address. something like CC00, C800,..
Normal you only have 3 options on these cards, thats why there are 3 pairs of two settings.

JP8 could indeed be the disk type.. For each A: and B: drivers are using 2x2 pin set.. So the first two would be for drive A.. Last two is to set for drive B..

Mostly to get the 1.44MB drive type you need to remove both jumpers, but it could be different on this card and other cards.

modem7
January 6th, 2016, 02:29 PM
Do you maybe know the CR type of the battery of the RTC? I know this is an old style larger one, and not the one we nowdays use.
Looking at the MT-8813 photo in post #1, comparing battery diameter to chip width, I think that the battery may be a BR2325 (CR2325, etc.)
But it may not be a BR2325 because of battery width (something that cannot be determined from the MT-8813 photo).

http://www.minuszerodegrees.net/temp/2/hd9034631.jpg