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How do I configure jumpers for JP5 - Mini-Micro-4

nc_mike

Experienced Member
Joined
Sep 28, 2014
Messages
473
Picked up a Mini-Micro-4 FDC, PII-158B. Here is the layout for the board:

https://th99.bl4ckb0x.de/i/C-D/50273.htm

I'll be connecting two known working floppy drives for my 5160 PC/XT, a 1.44 3.5" and a 5.25" 1.2M. The 1.2M floppy is a Teac FD-55GFR ( http://maben.homeip.net/static/S100/teac/diskette/Teac FD-55GFR 1.2MB floppy.pdf ). When I look at the setting for jumper block JP5, I'm not entirely clear on how to set the jumpers for mixing these two high density drives on the same twisted floppy drive cable. I'll make the 3.5" 1.44 my a bootable A: drive, and the 5.25: 1.2M drive B:

Based on the diagram, I'd assume the following jumper configuration to support what I want to achieve:

JP5A: Open
JP5B: Open
JP5C: Open (?) (would think this would be a no op)
JP5D: Open (?) (would think this would be a no op since they are the same for both HD drives)
JP5E: Open (?) (this one seems to be in conflict with having both a 1.44 and 1.2M drive)
JP5F: Open
JP5G: Open
JP5H: Open (?) (this one seems to be in conflict with having both a 1.44 and 1.2M drive)

Advise? I've had a mini-micro 2 drive FDC that I just could never get working after having tried many variations - I just kept getting an Error 2h when trying to boot from it an a read failure after booting up from my HDD, but the FDC BIOS appeared to initialize. I currently use a FTG FA-100, and both drives work fine with it, except it corrupts my XT-IDE attached CF boot drive when the 5.25" floppy is attached (so I just disconnected the 5.25" drive, which prevents that CF drive corruption - really odd, but after months of trying many variations I just gave up. I am hoping a third FDC will do the trick (hence, me trying the Mini-Micro-4 FDC, PII-158B as my last resort before giving up and just keeping the FTG FA-100 and only attaching the 5.25 drive in the rare instances I need one (and boot off the 3.5" drive without the CF card). If this attempt fails I thought maybe putting the drives on different cables since the board supports four drives on two different cables. I read somewhere that there is a terminator on 5.25 drives that can cause issues with two different HD floppies on the same cable.

I know, I'm being a bit stubborn trying to get both HD drives working well and working without the CF corruption; the fight with the machine has become personal!

Regards,
Mike
 
I've got a couple of the -2 boards and they work just fine.

The first thing to realize is that the table in TH99 for JP5 is screwed up a bit.

Drive types for a given drive are set with 2 jumpers, thus:

360K - closed, closed
720K - closed, open
1.2M - open, closed
1.44M - open, open

The next thing is to pair the jumpers off:

Drive A: JP5 A,B
Drive B: JP5 C,D
Drive C: JP5 E,F
Drive D: JP5 G,H

Note that these drive types only have meaning when the on-board floppy BIOS is enabled.
 
I've got a couple of the -2 boards and they work just fine.

The first thing to realize is that the table in TH99 for JP5 is screwed up a bit.

Drive types for a given drive are set with 2 jumpers, thus:

360K - closed, closed
720K - closed, open
1.2M - open, closed
1.44M - open, open

The next thing is to pair the jumpers off:

Drive A: JP5 A,B
Drive B: JP5 C,D
Drive C: JP5 E,F
Drive D: JP5 G,H

Note that these drive types only have meaning when the on-board floppy BIOS is enabled.


Interesting, unlike the MINI/MICRO-2, the MINI/MICRO-4 doesn't seem to have a jumper to disable its BIOS, unless the TH99 is missing it on their diagram. I don't have the MINI/MICRO-4 board yet to verify; I should have it by this Friday.

Yah, your point about the paired jumpers seems logical - that's the way my FTG FA-100 FDC worked as well. So I guess with what I want to achieve with just two drives my jumpers would be set the following way:

JP5A: Open
JP5B: Open
JP5C: Open
JP5D: Closed
JP5E: Open (not used)
JP5F: Open (not used)
JP5G: Open (not used)
JP5H: Open (not used)

Wow, that isn't anything like the table TH99! Assuming you are correct (and probably are), the table in TH99 should really have had DRIVE A spanning both JP5A/JP5B columns - ditto for the rest, serious table formatting error to drive is nuts (excuse the pun :)

Thanks,
Mike
 
Nahh, I really want to be able to boot from the A: drive from time to time and want the high density - else I could have just went with a multi-function board with an FDC port and avoided all this hassle LOL.

Also kind of weird, doesn't 11 mean closed and 00 mean open? - or do I have those reversed? I always thought 00 was binary for open (e.g not jumpered). If 11 means closed, then that's what printed directly on the MINI/MICRO-2 PCB for a 1.44M drive and is exactly opposite what the stason.org doc (http://stason.org/TULARC/pc/io-card...y-drive-controller-PII-151B.html#.VE0efxaKino).

Either way, no matter how I set the jumpers I always got an Error 2h when trying to boot from the 1.44M A: drive, and it would then default to boot from the CF card driven of the XT-IDE, but the floppy still couldn't read either 1.44M or 720 disks after boot up. I did have the BIOS on the card enabled, it did show the FDC BIOS loading during boot, but no go, and I know the drives and cable are good as they work and read/write and boot fine with the FTG FA-100 FDC (with the exception of my CF card getting corrupted when written to when the 5.25" 1.2M floppy is connected - super weird, and I don't think there is any BIOS address conflict in that region) I tried most everything with both cards - have no idea why the Error 2h with the MINI/MICRO-2 nor the CF corruption with the FA-100. Praying I'll have better lick with the MINI/MICRO-4.

Mike
 
I've got a couple of XT clones around here with HD floppy drives. One is using a Sysgen Omnibridge FDC--I think the other may be a WD 1002A-4 FOX FDC. But if you'd like, I can drop in a Mini-micro-2 controller and see what gives.
 
Would be interesting to see what jumper combos work for you. I didn't mess with the I/0 speed jumpers either. They are both set pins 1&2 closed (JP1 and JP2).

Mike
 
I grabbed an turbo XT clone off the pile that I knew had a XT-CF V2 in it.

When I opened it up, I found that I had already installed a Mini-Micro-2 FDC in it, with a 1.44M (A) and a 360K (B) drive attached.

The jumpers are configured as follows:

JP1: 1-2
JP2: 1-2
JP3: First two positions (1,2) no jumpers; second two (3,4) both jumpered
JP4: positions 1 and 3 jumpered (BIOS CA000H)
JP5: jumpered

It's a pretty well-loaded system. 2S, 2P, 2MB Aboveboard, AE2/T network, VGA.

Both drives format and read/write just fine. Works better than the XT that I used back in 1986 or thereabouts. The CF is a 192MB industrial SLC one--it'll probably outlast any spinning rust, given the low access frequency.

Hope this helps.
 
Last edited:
I grabbed an turbo XT clone off the pile that I knew had a XT-CF V2 in it.

When I opened it up, I found that I had already installed a Mini-Micro-2 FDC in it, with a 1.44M (A) and a 360K (B) drive attached.

The jumpers are configured as follows:

JP1: 1-2
JP2: 1-2
JP3: First two positions (1,2) no jumpers; second two (3,4) both jumpered
JP4: positions 1 and 3 jumpered (BIOS CA000H)
JP5: jumpered

It's a pretty well-loaded system. 2S, 2P, 2MB Aboveboard, AE2/T network, VGA.

Both drives format and read/write just fine. Works better than the XT that I used back in 1986 or thereabouts. The CF is a 192MB industrial SLC one--it'll probably outlast any spinning rust, given the low access frequency.

Hope this helps.

Thanks for going through the trouble! I give those a shot, but I migh have to modify the jumper for the send pair of drive jumbers because my 5.25" is a 1.2M drive.

Mike
 
Sigghhh, still no cigar. I received the MINI/MICRO-4 today. I had hoped that the problem might have been a bad MINI/MICRO-2 board. I set the jumpers for the 3.5" 1.44MB drive A: (open/open). I decided to just try to get the one drive working first, but then I hit vexing results.

I restarted the 5160. During boot I saw the FDC BIOS loading message. When it got the the XT-IDE BIOS screen I hit the A key to force it to boot off of the 3.5" 1.44M system floppy that I know boots-up fine with the FA-100 FDC. The next message was the same dreaded ERROR 2h! message I had gotten with the MINI/MICRO-2 FDC. The machine then starts booting off the the CF C: drive with no other issues. After the boot up completes, I try to do a DIR A: and get an ABORT, FAIL, RETRY just like I got with the MINI/MICRO-2 FDC, but not with the FA-100 that works with that 1.44M drive. I then tried to format a blank 3.5" 1.44MB disk, and the format worked. I copied over the DOS system files wit the /S parameter and tried rebooting off of the 3.5" drive again thinking maybe the MINI/MICRO didn't like disks I had formatted with the FA-100. I think the ERROR 2h! message has something to do with a bad disk sector or something? But I know the disk is good. After formatting it I was able to copy additional files from another 3.5" 1.44MB floppy drive that is a BackPack drive attached via the parallel port, and after copying files to the new disk in the A: drive, that disk reads fine using the BackPack drive. I tried every possible BIOS address option - same results.

I really am at a loss as to what to try next. I believe both MINI/MICRO FDCs are good, and I believe the drive is good as are the disks.

..the fun continues...thoughts?
 
Could be a XTIDE BIOS issue.

Pull the XTIDE and try booting from a 1.44M with the MM installed. If you can boot that way, then it's got to be XTIDE BIOS--and we can tackle that one separately.
 
Popped the M/M-4 back in, Pulled the XT-IDE, restarted, and the system went right to built-in Basic.
 
Just a thought, What bios revision is in your 5160, If it's the latest 05/09/86 see this page on modem7's site.
 
I was pulling my hair out recently due to a similar issue, I have 3 HD FDC cards for XT's, all different models, all were able to format/read HD in DOS and set the type properly.

One just never boots off HD, ever, not it's thing.
One only boots HD if you don't have a HDD ROM (by this I mean something like a WD1003, not XTIDE)
One only boots if you DO have an HDD ROM.

Load sequence was always C800 for HDD (standard then) and CC00 for FDCs (which also seemed to be the standard, and the lowest setting available on two of mine). Testing wasn't done on a single system or an authentic 5160. I only threw XTIDE in to the mix once, and that seemed to behave just like the normal bootup sequence. Information in this post may not be useful, hardly scientific, but mentioning it anyway.
 
Yes! My 5160 has the latest XT BIOS (5/9/86) that would explain it. I don't believe its an XT-IDE BIOS address conflict as it still has issues even with the XT-IDE pulled, and, I know my XT-IDE is using D800 anyway. I'll have to re-read the referenced thread. I didn't try every possible BIOS @ combo after I pulled the XT-IDE and now I don't recall seeing the FDC initialization message I had been getting when the XT-IDE was installed....so I'll double check that.

Thanks for the pointer to the 5160 late BIOS thread....it sounds like some cards might have that issue while others don't - which might explain why my FD-100 FDC works (though as I mentioned earlier, with the FD-100 card, the 3.5 1.44MB drive works perfect/boots etc and when the 5.25 1.2M is attached, my CF boot card gets corrupted. I could just hang it up and use the FD-100 and just the 1.44M drive and, on the rare occasions I need a 1.2M drive, hook it up, pull the CF card, and boot from the 1.44M floppy.


Regards,
Mike
 
Like chuck said, Try a generic 'ERSO BIOS' or burn a couple of Eproms with the 11/08/82 IBM BIOS, It's worth a shot.
 
Humm, but.....I had a specific reason for intentionally wanting the 5/82 BIOS - I want to keep using my beloved IBM Model-M keyboard, which I believe only the 5/82 BIOS supports. Will both of those deny me the ability to keep using my Model-M keyboard? Grrrrrrr....
 
I'm not at all clear why a BIOS change would defeat a keyboard interface--at least not on a 5150/5160--the keyboard interface on those isn't much more than a 74LS322 shift register.
 
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