Some overlay software needs to be installed in a 386 up then the hdd transferred over to the 16-bit machine.because the set up routine is 32-bit.

Apparently 32-bit is dead and no one likes P4s.

Personally, I would get a cheap 16-bit IDE controller card to connect an IDE drive or CF card using a passive adapter and either a dedicated XTIDE BIOS card or a NIC with an XTIDE BIOS ROM .

IMHO, life is too short for drive overlay software and I would not be surprised that
a) Using an overlay on a machine that old/slow the potential overhead from a software overlay may be annoyingly noticeable
b) you would need to go through some trial and error to even find a software overlay that works on a 286 (the installer for a given overlay solution may require a 386, but the actual overlay might as well)
c) When using an overlay on a disk, the said disk may or not be readable when connected to a modern PC running a modern OS

Full disclosure : I hate drive overlay software with a soul-consuming passion and would rather use a storage area that can only be accessed through IP packets encapsulated using RFC1149 (https://datatracker.ietf.org/doc/html/rfc1149 ), so I may be slightly biased .

I'd prefer DDO over disk compression any day.

I can’t remember if I originally used overlay on my 5170 or not. At one point it was a 6mhz 286 with dual 127mb quantum ELS drives. It definitely used a generic ide controller. I’ll look in my box of floppies to see if I have the disk. I suspect it was 1995 overlay software from Quantum.

I used an overlay on my 486-33 for several years in the mid 90s without issue. But, I wasn’t moving drives around or doing anything too extreme.

I think I remember having issues finding a DDO that would work on my 286 - this was before XTIDE was established though. It's by far the better solution these days (unless you have an oddball situation like with my 486DLC and can't access >8GB using XTIDE....).

For the OP, his best option is an all-in-one XTIDE CF / IDE card.

Caluser2000 wrote on 2021-06-07, 06:34:

I'd prefer DDO over disk compression any day.

I hear that dedicated masochists have combined both for that extra painful experience . Bonus points if one runs on a nice and slow CPU and on the slowest MFM drive available or on a parallel ZIP drive . The truly blessed get to see their DATA experience the naughtily corrupting influence of such a setup... Somebody call Clive Barker, this just may be the start of a screenplay for the next Hellraiser. 😉 EDIT : Or maybe even a game ? How would "Clive Barker's Not booting" sound ? 😉

Joking aside, if you are referring to Stacker/Doublespace/Drivespace , I agree on a rational level, though I somehow subjectively find myself hating DDOs more (maybe some therapy is in order) .

That being said, current filesystem level compression and deduplication, in ZFS for example, is not a bad thing, IMHO .

Getting back on topic, another option for OP would something like the EIDE MAX II from Promise . See http://www.oldschooldaw.com/forums/index.php?topic=4598.0 AFAICT, that has a BIOS that can handle drive sizes up to the LBA-28 limit and also has 2 IDE ports . This has the elegance of being a single card solution . Probably not easy to find, though .

Hi i just wanted to say thankyou to all who helped in this post i have now got the xt - ide and it works great however i may be having a ram issue with this pc??
when i boot the pc and it does the ram check it shows 640k and then next to it it shows 0353k
sometimes when i boot it will only display 0353k
when i run mem from dos it always shows the full 640k but then when i got to play games like commander keen it only says 318k available to game but the game runs fine with no issues.
just wondering if this is a ram issue? as sometimes on boot it will show a ram error and refuse to boot but then i reset and everything runs fine.
why do games like commander keen only show 318k when mem from dos shows 640k

Show the output of "mem /c" and post a copy of your config.sys and autoexec.bat files.

how do i make it show the output of mem /c

You can use the output redirection of the DOS command prompt to send the text to a file:

mem /c > file.txt

... that will result in file.txt containing the characters that would have been printed on-screen.

ok i will try that soon and post the file

Ok, so you actually have 573kbytes free - which isn't brilliant, but not horrendous either. Ignore what the game tells you - we don't know how it is calculating that.

So you can free up some more of that 640kbytes by adding himem.sys and loading DOS high, which is perfectly possible on a 286.

Add to your config.sys, at the very start:

device=C:\DOS\HIMEM.SYS
DOS=HIGH

That should take you to 600kbytes free, or more.

DOS memory management is an art/science in itself. There are some helpful tips here: Dos 6 conventional memory tricks

But, things to note on a 286:

- You don't have EMM386 or EMS in general - unless (a) you use the very slow EMM286, (b) have a very specific 286 chipset which supports it, or (c) buy a hardware EMS ISA card (you may or may not need EMS memory depending on which games you want to play).
- You don't get UMB support to load drivers/DOS components out of 640Kbytes - unless your chipset is on the compatability list of a memory manager like (a) 'The Last Byte' or (b) 'UMB_DRVR'

BTW, What version of DOS are you using? I'd not really want to use anything earlier than DOS 5. Other than being slightly larger on-disk and taking up a small handful of kbytes more in-ram, there's really no reason (other than nostalgia) to use anything other than 6.22.

This machine probably has no high memory (above 640kB) at all. So himem.sys can only consume part of conventional one 😀

Well, if it only has 640kb of physical ram, yeah, that would certainly stop using the HMA! 😀

Nice machine, so clean looking and moddest! Just fireballed for some more pictures online. Reminds me somehow of the time of early LIMulators (EMS 3.2?).
For the very poor people that couldn't afford proper EMS boards or SIPPs at the time, there were EMS Managers made that used overlay files on the HDD.
Was very slow, but maybe good enough for Lotus 1-2-3, AutoSketch/-CAD or PC/GEOS. A bit like x87 NPU emulators of their time.

A few postings earlier you guys discussed using compression..
Well, it's actually better than its reputation. Just give it a try! Double Space does a fine job, from what I can tell.
I'm using it on an XT compatible with MS-DOS 6.22, a 4,77MHz CPU and a 20MB MFM fixed disk - 8" version!
Performance is not bad here, seriously. I would even say that it is slightly better than before.
Of course, that's just in my case. Maybe the interleave factor choosen for that HDD was poor
and the disk compression compensates for it , or something along these lines.

hi all im running dos 6.22 the bios only shows 640k of ram but in the specs of the pc it says it has 1mb and the rest can be used as extended but im not sure how to set this up as the bios disk i have only shows the 640k

and thank you Jo22 it is a very beautiful pc its very nice.
i will try adding those parameters to the system config file and see what happens?
maybe i need another bios disk instead of the default hp one i have?

well that did not work 🤣

vkcpolice wrote on 2021-06-29, 03:43:

well that did not work 🤣

Extended memory starts after the first megabyte of RAM .

vkcpolice wrote on 2021-06-29, 02:24:

hi all im running dos 6.22 the bios only shows 640k of ram but in the specs of the pc it says it has 1mb and the rest can be used as extended but im not sure how to set this up as the bios disk i have only shows the 640k

You can find how much physical memory you have, by counting memory chips (under PSU i can see Toshiba IC which looks like DRAM).
If there is really 1MB available, you can try UMB drivers like The Last Byte Memory Manager http://files.mpoli.fi/unpacked/software/dos/u … ip/contents.doc or UMBDRVR http://www.win3x.org/win3board/viewtopic.php? … 070&language=en. Maybe your chipset is supported there.
Can you provide detailed photo of the whole motherboard ?

My guess is that it does have 1mb fitted, but your BIOS doesn't offer the ability to do anything with the 640-1024kb reserved region.

In the first image you posted I think I see 4 rows of 3 DRAM chips under the PSU. My guess is that you have 8x 128kbyte chips and 4x parity chips for a total of 1024kbytes.

Can you get any clearer images of your "CHIPS" chipset? According to the documentation with "The Last Byte" memory manager, certain Chips & Technologies designs allow the use of the 384KByte region as upper memory blocks, so you could load DOS, drivers and other things high. Here's the list of 82C2xx designs that are supported:

2.7 Chips and Technologies

Part Number Shadow Ram Address Range Organization
----------- ---------- ------------- ------------
82C100 64k Page Frame 4x16k
82C212 384k A0000-FFFFF 24x16k
82C222 384k A0000-FFFFF 24x16k
82C230 384k A0000-FFFFF 24x16k
82C235 384k A0000-FFFFF 24x16k