LGR was dealing with the same problem. Look at his video: https://www.youtube.com/watch?v=yyL_a9QE8ag

GSetup is the name of that utility.

Well I tried it and it behaves oddly ... When I go to exit, the computer hangs and makes a continuous beep. I try to reboot anyways and the PC still sees them as 360KB drives for both. LGR's computer is an IBM AT, not an XT, and mine is just a clone so unfortunately it doesn't work ...

Oh and also despite from being manufactured in 1988, this computer uses ... An 8088 ^^

I don't think you've done something wrong. I'm having the same problems with my XT machine.
Currently, I'm using the 720KB drive in 360KB "mode".

Deksor wrote:

Next I tried to mount DRIVER.SYS but unfortunately it doesn't corresponds to what I want (having the "A" drive recognized as a 1.44MB drive)

Driver.sys perhaps maps the physical drive "A" or "B" to a new, virtual one..
So it might be necessary to specify another driver letter (N:, M:, etc). Also make sure the "last drive" setting is set accordingly.

Deksor wrote:

And next I tried DRIVPARM but DOS tells me that this command isn't recognized ...

I know. DOS 3.x doesn't support it properly. In early PC-DOS it wasn't officially supported, either (ie, a hack was necessary).

Well in fact it looks like it attempts to write to an RTC board but since mine is dead (f*cking varta T_T) I can't really do anything. Though I may someday be able to fix it as these board are still very simple (no traces inside the board so no cut traces that you can't find) and the chips can be found on ebay for most of them.

You may already have read this, but if not go to the floppy section of the document

https://sourceforge.net/projects/opensoc86/fi … ios/pcxtbios25/

I'm not specially trying to boot from a 1.44MB floppy, I just wantto access to them ^^

Right under the BIOS chip in the computer, there is a second socket, so I guess I could expand the bios capabilities, right ?

If I do that, what else could be interesting to have ?

Imperious wrote:

You may already have read this, but if not go to the floppy section of the document

https://sourceforge.net/projects/opensoc86/fi … ios/pcxtbios25/

Thanks for the link! It is interesting and could really help Deksor if the XT in question is a faithful clone.
Unfortunatelly, I can't give any feedback to this matter because my clone isn't a 1:1 copy of the IBM XT.
That 2M-XBIOS Deksor used looks promising, though, maybe it will make at least my 720KB drive work properly.

Out of curiosity, does all this kind of cheating also work on todays floppy emulators ?
Just asking. I'd also like to know if you can use something like a Gotek to replace a 3.5" drive with 320KB/360KB geometry.
If so, I could safely put my old 720KB drive to rest (until I need it again to backup troublesome DD disks). ^^

Edit: Just tried the 2M-XBIOS and it seems working here (device=2m-xbios.exe A:1 B:3, no /13 switch required):
I re-formatted a 3.5" 360KB disk using Format without problems. Machine is a Nixdorf 8810 M35 (specs).

krivulak wrote:

LGR was dealing with the same problem. Look at his video: https://www.youtube.com/watch?v=yyL_a9QE8ag

GSetup is the name of that utility.

That doesn't work on PC/XT class computers.
GSetup is a configuration tool for the CMOS configuration found in AT-compatible machines (most clones have a setup tool built into the BIOS, which you usually can access by pressing 'del' on startup, or some other key).
PC/XT doesn't have CMOS configuration.

I use DRIVPARM myself in a CBM PC-I and it works in MS-DOS 3.3. Unless you use some special patched version of MS-DOS 3.3 it is a bit strange that it isn't even recognized on your computer.

The DRIVPARM line must be in config.sys.
I'd guess the 3.5" drive is drive B: in your system?
So it should probably look like:
DRIVPARM=/D:1 /F:2 /I
Since your BIOS most likely supports only DD drives and doesn't know of 3.5" drives.

Alternativly a floppy disk controller card with it's own BIOS extension is a good option to get regular HD drive support.
I use the Wish Deisgn House WDH-1001F in another XT class computer: http://retronn.de/imports/hwgal/hw_controller … 001f_front.html

what floppy controller card do you have? not all FDC can see 1.44mb drives.

Like I said, it's munch newer than the machine (came with a cheap 386 from the early 90's I think).

I managed to make it detect 1.44MB floppies ! I patched IBMBIO.COM. This allowed me to use DRIVPARM. Even though DRIVPARM was not outputing any error, it didn't seem to make me able to read bigger floppies ... However I re-tried 2m-xbios.exe and now it works 😮

Unfortunately, in order to be able to edit ibmbio.com, I had to create a boot floppy and use the attrib from one of my windows 98 machine to remove the "hidden" attribute, I don't know how to use DOS 3.3's attrib and I've read that it can't do that ... So I don't know how I can unhide the IBMBIO found inside my hdd to replace it with the patched one 🙁

Edit : okay so now for some reasons 2m-xbios works fine from the HDD without touching to the ibmbio.com file. I don't know why, but that's now a problem solved 😀

Allright, so I received an 8087 and a NEC V20 for that computer. I installed both of them and they both work perfectly ^^

Now, at the beginning, I talked about a ram card of some sort that doesn't seem to work. Here it is !

Now the problem isn't a driver problem (... for now ?). Simply when I insert the card in the computer, the computer doesn't POST anymore. I checked if the caps were shorting and they don't so the problem might not be there ... Any ideas ?

I tried this card again, obviously the computer didn't output anything on the screen but at some point I tried to press the numlock key and the numlock led turned on ! I wasn't able to reproduce this but it looks like the card is in fact messing up the signals and not the voltages so there might be a dead chip or maybe there are caps that are dead (this is going to be a pain to replace and it will be costly 🙁 )

Do you have a picture of the motherboard?

Some time ago i asked Plasma from VCF to change his BIOS so that it only stops to look for option ROMs at FE00h. Reason for this is that a lot of XT clones have a single 27256 ROM socket for IBM CASSETE BASIC, which is mapped from F600h to FDFFh. That socket will then become available for option ROMs which one can use for High Density Floppy support, for instance.

This board has two rom sockets. One is filled with the bios an the other is empty. I've got two other XT motherboard which are coming from two IBMs 5160 they have two rom chips so I guess I could just swap them if I want an IBM bios

The only bit of advice I can give with respect to the Ram card is check for dry solder joints and whilst turned on check and see if any of the chips get
unusually hot.
Hot Ram ic's are a common problem with older computers, especially c64's and others from that era.

I checked if there was any overheating chip and all I can say is that these 4 chip are getting a little warmer than the rest ... the rest being cold

Now, you may see right next to the red area that I made, a jumper with "bank 0" written under it. there is also a "bank 1" position and so I flipped it.

With the jumper being set in the other position, the computer POSTs ! ... with half the ram ... When the computer is set to 640KB of ram, the computer starts with 384KB. When it's set to 512KB, it starts with 256KB of ram.

I don't really know what's happening there ...

It is still unclear to me, what you want.

What do you expect the RAM card to do?
Where does the RAM actually decode to?
If your computer has already 640 kB, what is the point to add a 512 kB card? Shouldn't it be a EMS card then?

Actually I don't know what kind of ram card this is ...

For sure it has ram chips on it, but I don't know if it's an XMS card, and EMS card or whatever else ... I'm new to this stuff so I don't know as munch as you do ^^