Ok with that info and as i dont have the other side bracket, i used some qtip to get the gap and the drives fixed in the cage.
Maybe someone have the other side bracket and want to trade with mine..

You don't really need the extra side bracket if your case has the bottom mounting hole. Is there a plastic circle insert on the underside of your chassis?

What you're really missing is the black plastic trim bezel that's supposed to snap around the drives after they are installed

I have that long IBM Color CGA card installed. Im correct that they dont can output monochrom?
The later 8bit ATI wonder cards can do both?

Jackhead wrote on 2024-12-30, 15:25:

Did IBM release a 5160 with two floppy drives on some point??

I dont know if they did but I have a late model XT that came with 640k on the main board and two Y-E Data floppies in the left hand bay with those side brackets and the thin front mount bezel around them so I would hazard to guess yes?

Jackhead wrote on 2024-12-30, 17:50:

I have that long IBM Color CGA card installed. Im correct that they dont can output monochrom?

The CGA card supports four kind of text modes: 40x25 without the color burst on the composite jack, 40x25 with NTSC color on the composite jack, 80x25 without the color burst on the composite jack and 80x25 with NTSC color on the composite jack. On the RGBI connector, there is no difference between the "with color" and "without color" modes. As the modes "without color burst" do prevent NTSC monitors from decoding color because the reference burst in the horizontal blanking is missing, but they do not prevent the NTSC color carrier on non-grayscale colors, you are supposed to only use the colors 0 (black), 7 (light gray), 8 (dark gray) and 15 (bright white) in those modes, because the color information of other colors will be seen as strange dot/line patterns. Text mode DOS software of that era often respects it, and falls back to a grayscale-only scheme if the "no colorburst" modes are set (you initialize them with "MODE BW40" and "MODE BW80"). In that sense, the CGA card is able to "output monochrome".

But: The CGA is unable to output a picture at MDA resolution/scanrates. You can't get the nice text quality of the MDA from a CGA card. You can't run Hercules software using a CGA card. A 5151 monochrome monitor will not work with a CGA card (there are rumors that it might actually take physical damage by being driven from a CGA card, as it relies on a "sufficiently high" horizontal scan rate). Trying to switch to the MDA monochrome mode using "MODE MONO" will tell the BIOS to stop interfacing to the CGA card and start interfacing to an MDA/Hercules card instead. IIRC MS-DOS test for the presence of an MDA/Hercules before executing the switch-over manouvre, but if it didn't (or you remove that check), video output will just stop working until you use "MODE" with a CGA-type text mode again (that is BW40, CO40, BW80, CO80).

Jackhead wrote on 2024-12-30, 15:25:

Ok for testing i did connect both drives on my controller. System boots both drives without error. Well i had to dip switch 7 of […]
Show full quote

Ok for testing i did connect both drives on my controller. System boots both drives without error. Well i had to dip switch 7 off.
A: is also able to read a Floppy, but B dont. The point is i dont know the condition of the 1,2MB drive.
Maybe its broken and someone removed it.. The Seller cant tell me more.
But when the drive boots without error, its good starting point.

A 1.2MB drive configured for use in an IBM PC rotates all kinds of disks at 360RPM. A 360KB drive configured for use in an IBM PC rotates at 300RPM. This means the output of the 1.2MB drive will be 20% too fast when reading, and the disk performs a full rotation before you can format 9 sectors to it, unless the floppy controller is also clocked 20% faster. The AT BIOS is able to configure AT-type floppy controllers to deal with the extra speed (by switching them to a 9.6MHz clock instead of an 8MHz clock used for DD floppies in DD drives). Your XT BIOS is unable to do so. Without some kind of BIOS extension or changing some jumpers on the 1.2MB drive to use 300RPM, you will not be able to read any standard floppy in it without BIOS extensions.

Got it, thanks for the explanation!

Installed 2M-XBios for 1,2MB FDD support, both drives working now on the 16bit multi i/O board.

Jo22 wrote on 2024-12-30, 16:12:

...

It's of course not a must. It's just an idea, to get the most of it on the 5153.
The ATI Small Wonder (and the Paradise equivalent) sometimes appear for 50€ or so on eBay.

I wasn't aware Paradise ever made a card similar to the ATI Small Wonder... do you have more info about it?

MMaximus wrote on 2024-12-30, 22:03:

Jo22 wrote on 2024-12-30, 16:12:

...

It's of course not a must. It's just an idea, to get the most of it on the 5153.
The ATI Small Wonder (and the Paradise equivalent) sometimes appear for 50€ or so on eBay.

I wasn't aware Paradise ever made a card similar to the ATI Small Wonder... do you have more info about it?

Hi, there was the Paradise PVC 4 (1985). Commodore PC10-III had it, it seems. And Schneider Euro XT?
https://forum.vcfed.org/index.php?threads/par … asheet.1240463/

https://www.dosdays.co.uk/topics/Manufacturer … radise/pvc4.php

Then there was the Paradise PVC 2 in 1986 or so. It was used in Commodore PC1, for example.
It's more like a spiritual predecessor to the Small Wonder, though.
Similar features and use case, but different circuit. They all had Plantronics support.

https://www.vgamuseum.info/index.php/cpu/item … se-systems-pvc2

https://theretroweb.com/motherboards/s/commod … c-1-part-380074

https://www.dosdays.co.uk/topics/Manufacturer … r_mono_card.php

Some Commodore PCs without on-board video had the AGA card installed, which used an ATI chip.
(The earliest PC10 had an MDA card without graphics.)

The Paradise Pega2 looks not bad, here a video where someone did a repair and at the end a benchmark with other EGAs.
https://www.youtube.com/watch?v=GTai7o5E0Qk&t=1117s

Jo22 wrote on 2024-12-31, 05:06:

MMaximus wrote on 2024-12-30, 22:03:

Jo22 wrote on 2024-12-30, 16:12:

...

It's of course not a must. It's just an idea, to get the most of it on the 5153.
The ATI Small Wonder (and the Paradise equivalent) sometimes appear for 50€ or so on eBay.

I wasn't aware Paradise ever made a card similar to the ATI Small Wonder... do you have more info about it?

Hi, there was the Paradise PVC 4...

Thanks for the detailed info. From what I gather, this looks like a multi-mode CGA card, but I'm not sure it had the same features as the ATI Graphics Solution / Small Wonder -mainly the ability to display CGA graphics on MDA monitors...

It’s worth noting MS-DOS 3.31 and its IBM equivalent were sold brand new through 1991 as the goto for XT class systems due to the small memory footprint while having 512mb hard disk support (theoretically) and HD floppy support, while bypassing the horrible Dos 4 fiasco.

Tandy , Compaq and others used Dos 3.31 on brand new machines long after its expiration and you can too.

I tend to like 3.3 on anything not an AT class, 5.0 on 286 and modest 386, and 6.whateverdiskIpickupfirst on later 386 up.

rmay635703 wrote on 2025-01-01, 03:54:

It’s worth noting MS-DOS 3.31 and its IBM equivalent

Wait a minute...
I know there was Compaq OEM version of MS-DOS 3.31.
Maybe even some other OEM versions?
But was there generic MS-DOS 3.31 ?
And was there IBM PC DOS 3.31 ?

I had this floppy in my set. I wonder its for internal use only. Is this kind of re/preview beta floppy?

Got today a Model F. Spend some hours to clean anything. Removed the keycaps, washed it. Like the Result.

before:

cleaning:

Jackhead wrote on 2024-12-30, 12:52:

Thanks guys, for the informations!
I think i go with installed dos 5.0. The loot includes also the original 5.0 IBM Floppys.
6.22 feels wrong, and i see 5160 boottimes with it..

Yes, MS-DOS 5 is fine.
Personally, I like using MS-DOS 6.2x because I know it "just works" and I can remember the commands (I want to know how to use one DOS properly, at least).
In order to have all the old commands and utilities, too, I do install MS-DOS 6.0 first and then 6.2x. And then PC-Tools 7! 😁

Jackhead wrote on 2025-01-04, 18:44:

Got today a Model F. Spend some hours to clean anything. Removed the keycaps, washed it. Like the Result.

Looks good! Well done! 😃

Jo22 wrote on 2025-01-27, 06:02:

Personally, I like using MS-DOS 6.2x because I know it "just works" and I can remember the commands

Personally, I like using DOS 6 because I don't *need* to remember the commands.
It's the first version of DOS with complete online(*) documentation - no need to dig in the pile of dusty books, no need to search the web for scanned manuals...

(*) "online" in the traditional sense - it's all in C:\DOS\*.HLP, not via some retarded web service.

Grzyb wrote on 2025-01-27, 07:06:

Personally, I like using DOS 6 because I don't *need* to remember the commands.
It's the first version of DOS with complete online(*) documentation - no need to dig in the pile of dusty books, no need to search the web for scanned manuals...

Good point. Though Jackhead has the big physical books of DOS 5 in reach, so..

Anyway, what I meant was that I do personally prefer trying to understand one DOS properly,
rather than messing a round with a dozen of versions all day long.

That being said, I think it's good to have a small collection stored away for trouble-shooting.

Such as (incomplete list):
- MS-DOS 2.11 for really old games, Windows 1.x
- DOS Plus 1.2 for running DOS 2.11 and CP/M-86 programs on FAT formatted media (10 or 20 MB HDD, 360 KB floppy), it can be a bridge between both worlds
- PC-DOS 3.30 for 80s GEM, Windows 2.x, old disk utilities (it's an allrounder)
- Compaq DOS 3.31 for XT users in need of gigantic 512MB partitions
- MS-DOS 5 for Windows 3.0 (has WINA20.386 file needed for 386 mode) and GeoWorks 1.x/2.x (they use a patch for DOS 6+)
- MS-DOS 6.x for Windows 3.1x and WfW (has Windows utilities)
- The forgotten MS-DOS 6.20 for users that build period-correct PCs from 1993 and thus avoid 6.22
- MS-DOS 6.22 for Windows f. Workgroups 3.11 (are an couple)

Edit: Interesting! I've just read in an old review about "MS EM" that DOS 2.11 was slower processing than DOS 3.2 (then current)..
Edit: By the way, MS-DOS 3.2/3.3 has a bug in FDISK. If HDD is larger than 32MB, data corruption happens. IBM PC-DOS 3.30 doesn't have this bug. It just stops at 32MB size, partition will be fine.

DR DOS 5/6 and Novell DOS 7 are also good to have, they were the underdogs so to say.
Especially NV7 had useful P2P networking features (DOS/Win3x), like Warp 3 Connect or WfW 3.11.
I do like to think these three are special editions, like Pokèmon Yellow/Crystal/Emerald.. ;)

PTS/Paragon DOS for experimental builds.
Lots of switches in startup files. Is said to be made in assembly.

PC-DOS 2000 seems to be popular among Turbo XT and hot-rod PC fans, too.
It can make good use of UMBs and EMS cards, I assume.
It has features more modern than found in MS-DOS 6.22, newer DOS core.

But MS-DOS 5.0a is fine and solid, really. In the world of the user, it was the next big release straight after DOS 3.30.
Many XT users in 1990 had used or known about MS-DOS 5.
I suppose that most got hold of a copy within months.
Exchanging "backup copies" and borrowing "start-up disks" was very common back then. ;)

PS: Wendin DOS and PC-MOS/386 are fine for those users who want to run their IBM PC or AT/386 like a little mainframe.
Terminals can be attached, DOS programs can be multitasked (useful for running a lot of small utilities, text mode games, compilers, GW-BASIC etc).
A 386 is recommended because of better memory managment.
Otherwise, same memory constraints as when using TopView or DESQView.