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subrosian
February 28th, 2017, 08:25 PM
I have an IBM 5170 8mhz with 512K of memory running DOS 6.22. When I boot the computer with my mouse driver, I get the following when running mem.exe:
Total Memory: 512K
Used Memory: 74K
Free Memory: 438K

When I run Simcity, it says "156732 FREE, 170000 required to run".
When I run Commander Keen 4, it says "Memory available to game: Standard: 195Kbytes".

The only changes I have done from the stock setup is adding a 3COM 3C509TP network card, a Cirrus Logic GD5401 VGA graphics card, and a 3.5" 1.44MB floppy drive.

Where is the other ~200K going?

Also, I guess I'm looking to top off the standard memory to 640K and getting some XMS memory (1+ MB). What is the best way to do this today? I noticed Lo-tech made RAM boards and EMS boards (though both out of stock), but i haven't found anyone making new XMS boards. If there is no one making new cards, is there a recommendation for old cards that are well supported?

modem7
March 2nd, 2017, 11:24 PM
When I run Simcity, it says "156732 FREE, 170000 required to run".
When I run Commander Keen 4, it says "Memory available to game: Standard: 195Kbytes".

Where is the other ~200K going?
I am unfamiliar with those games, but I suspect that what they may be indicating is the 'free' RAM available after the game has loaded.

SpidersWeb
March 2nd, 2017, 11:53 PM
Yeah will be after it's loaded a certain part of the code.
SimCity no doubt expects a 640KB system.

My personal favorite for XMS+topup were some of the 16bit AST boards - some models allowed up to 3MB of RAM, and would let you map 128KB of that to top up your base memory. But they can be hard to find and you'd want to google the manual to check what options it has before purchasing.

The Lo-Tech 1MB board will fill in your 128KB as well as give you options to make some upper memory blocks (so you can put DOS and drivers in there instead of conventional). But I'm not sure how much it being 8 bit affects performance. I know XT class memory cards do slow down the system - even noticeable on the RAM count, but I haven't tried the Lo-Tech board on an AT yet.

Trixter
March 3rd, 2017, 10:23 AM
I have an IBM 5170 8mhz with 512K of memory running DOS 6.22. When I boot the computer with my mouse driver, I get the following when running mem.exe:
Total Memory: 512K
Used Memory: 74K
Free Memory: 438K


Try using the "cutemouse" driver, it takes up less than 5K resident RAM and might help. You can also set buffers=1 in config.sys to free up a little bit more, although your disk I/O will get slightly slower as a result. This might free up enough RAM for you to run Simcity.


When I run Commander Keen 4, it says "Memory available to game: Standard: 195Kbytes".

That message is misleading, it's saying how much memory it sees available after it has loaded itself. MEM.EXE is what you should be using for an accurate report.

Trixter
March 3rd, 2017, 10:25 AM
SimCity no doubt expects a 640KB system.

No, it was rated to run on a 512K system: http://www.mobygames.com/game/dos/simcity/techinfo

Scali
March 3rd, 2017, 10:59 AM
Also, I guess I'm looking to top off the standard memory to 640K and getting some XMS memory (1+ MB). What is the best way to do this today? I noticed Lo-tech made RAM boards and EMS boards (though both out of stock), but i haven't found anyone making new XMS boards. If there is no one making new cards, is there a recommendation for old cards that are well supported?

I think you've landed in an unfortunate niche here...
The Lo-tech RAM board is meant for PCs and XTs to top up the memory to 640k (actually to the full 1 MB, but you can't readily access the memory over 640k because that's a reserved area).
EMS is again used for expanding the memory on an 8088-based system.
Most 286 clones would have SIMM sockets on the motherboard, and come with at least 640k standard. So they wouldn't need any card to get XMS, let alone conventional memory.
I'm not sure if the Lo-tech card would be an option for you, since it's an 8-bit card. If it even works at all in an AT, the memory would be slower than the rest of the conventional memory.

However, IBM offered a few options for the 5170 back in the day. The interesting thing is that they have a feature to 'top up' the conventional memory to 640k with some of the memory installed.
There's a list on modem7's site: http://minuszerodegrees.net/5170/cards/5170_cards.htm
This one seems to be the most interesting option: http://minuszerodegrees.net/5170/cards/ibm_emea.htm
It seems to take SIMMs, which is convenient, and it takes the most memory of all cards listed.

Chuck(G)
March 3rd, 2017, 11:17 AM
You might try running an earlier DOS with a smaller memory "footprint".

offensive_Jerk
March 3rd, 2017, 11:28 AM
You might try running an earlier DOS with a smaller memory "footprint".

I was wondering about this too. Which version of DOS would be a good choice for an AT as far as a balance between free base memory and features?

Chuck(G)
March 3rd, 2017, 11:42 AM
Depends on your hard disk needs. If you're happy with a smaller hard disk, then DOS 3.3 (or Compaq DOS 3.31) is stable and pretty decent.

krebizfan
March 3rd, 2017, 11:46 AM
Nearly all EMS 4.0 expansion cards for AT would fill memory starting at either 512k or 256k* if needed to provide for the full 640kB. The remaining memory on the card could be split between EMS and XMS through the setup program.

* Not just to let people skip filling the motherboard RAM sockets but also to help multitasking with DesqView.

AlexC
March 3rd, 2017, 01:31 PM
When I run Commander Keen 4, it says "Memory available to game: Standard: 195Kbytes".


From memory (no pun intended), you need to get that number up to around 300KB before Commander Keen 4 (and 5 and 6) will run, though less than that if you have EMS. Even with all the suggestions on this thread I don't think it's possible with only 512KB to start with, since it equates to around 540KB of free base RAM. I think SimCity is less greedy, though.

AlexC
March 3rd, 2017, 01:38 PM
Another option is to put a Hercules card in there and use something like PC-DOS 7 to map upper memory into that card's graphics RAM. It'll be slower than system RAM but you might be able to get most of DOS to load in there. It's a bit arcane, though, and not an easy option. And it still won't get Keen 4 running.

Trixter
March 3rd, 2017, 01:50 PM
From memory (no pun intended), you need to get that number up to around 300KB before Commander Keen 4 (and 5 and 6) will run, though less than that if you have EMS. Even with all the suggestions on this thread I don't think it's possible with only 512KB to start with, since it equates to around 540KB of free base RAM. I think SimCity is less greedy, though.

I just measured Keen4 CGA by letting it run the demo for a minute and it uses up to 574KB of RAM. So 640K required for Keen4 to run.


Another option is to put a Hercules card in there and use something like PC-DOS 7 to map upper memory into that card's graphics RAM.

That will only gain 62KB extra RAM, and would not allow him to run games.

The best solution is a 16-bit EMS 4.0 board, like the Intel Aboveboard. It can map into lower RAM and fill it up, plus provide EMS for whatever is left.

Stone
March 3rd, 2017, 01:52 PM
I was wondering about this too. Which version of DOS would be a good choice for an AT as far as a balance between free base memory and features?


Depends on your hard disk needs. If you're happy with a smaller hard disk, then DOS 3.3 (or Compaq DOS 3.31) is stable and pretty decent.With DOS 5.00 or 6.xx you can use the HMA to load DOS high which yields more free base memory than any of the DOS 3.xx versions.

Stone
March 3rd, 2017, 01:54 PM
Another option is to put a Hercules card in there and use something like PC-DOS 7...Hmmmm...., not on a 286. 7 requires a 386.

Scali
March 3rd, 2017, 01:54 PM
With DOS 5.00 or 6.xx you can use the HMA to load DOS high which yields more free base memory than any of the DOS 3.xx versions.

While that is true, you need to have HMA first. Which this system doesn't have, it only has 512k conventional memory, nothing else. So until it is fitted with a memory expansion card, DOS 3.xx will give you more free memory.

AlexC
March 3rd, 2017, 01:57 PM
I just measured Keen4 CGA by letting it run the demo for a minute and it uses up to 574KB of RAM. So 640K required for Keen4 to run.

That will only gain 62KB extra RAM, and would not allow him to run games.

The best solution is a 16-bit EMS 4.0 board, like the Intel Aboveboard. It can map into lower RAM and fill it up, plus provide EMS for whatever is left.

I have the VGA version and I'm pretty sure it runs in 550KB, but that's not to say it won't use more if it's available.

The extra 62KB (more likely around 45KB in reality once all supporting drivers are loaded) certainly won't get Keen 4 running, but it might help with others.

I agree an EMS board is best, but they are like hen's teeth (I have one for sale here (http://www.vcfed.org/forum/showthread.php?55828-Orchid-RamQuest-XT-AT-8MB-RAM-board-with-4MB-installed-EMS-4-0-and-UMBs-on-XT)). Hercules cards are readily available and cheap.

AlexC
March 3rd, 2017, 01:58 PM
Hmmmm...., not on a 286. 7 requires a 386.

I have it running on a V20.

More info here (http://www.robvanderwoude.com/dosmem.php) (bottom of the page).

Stone
March 3rd, 2017, 03:42 PM
While that is true, you need to have HMA first. Which this system doesn't have, it only has 512k conventional memory, nothing else. So until it is fitted with a memory expansion card, DOS 3.xx will give you more free memory.I figured that since it is such basic memory management I didn't see a need to include it. Kinda like you can't put a gallon of water into a quart bottle. :-)

Stone
March 3rd, 2017, 03:56 PM
I have it running on a V20...Which is not at all of relevance to the OP's situation on his 5170.

AlexC
March 3rd, 2017, 04:08 PM
Which is not at all of relevance to the OP's situation on his 5170.

It's completely relevant, since a 5170 has an 80286 whereas a V20 is basically an 8088 with a few 80186 instructions.

PC-DOS 7 will run fine on his 5170. It does not, as you stated earlier, require a 386.

Chuck(G)
March 3rd, 2017, 04:24 PM
Probably confusion between PC DOS 7. (an IBM issued product) and MS-DOS 7.x (comes with Windows 9x), which does require a 386.

Stone
March 3rd, 2017, 04:30 PM
Probably confusion between PC DOS 7. (an IBM issued product) and MS-DOS 7.x (comes with Windows 9x), which does require a 386.Exactly... I don't use PC DOS 7. :-)

Caluser2000
March 3rd, 2017, 05:04 PM
Exactly... I don't use PC DOS 7. :-)It can free up as much ram if not more than Ms-dos 5 or 6.x

Caluser2000
March 3rd, 2017, 05:34 PM
To put it in perspective here's vwestlife's free conventional mem. comparison list, without any memory managers loaded, of various MS/PC Dos variants:

"I just went through all my boot disks, and ran CHKDSK on each one to display the amount of free RAM (out of 640K) on each one, using a totally clean boot (no CONFIG.SYS or AUTOEXEC.BAT):

PC DOS 2.00 ... 630,672 bytes
PC DOS 2.10 ... 630,672
PC DOS 3.10 ... 616,432
MS-DOS 3.10 ... 616,432
PC DOS 3.21 ... 609,392
PC DOS 3.30 ... 600,528
MS-DOS 3.30 ... 600,368
IBM DOS 5.00 ... 593,328
MS-DOS 5.00 ... 593,328
MS-DOS 6.00 ... 592,256
IBM DOS 6.10 ... 593,056
MS-DOS 6.22 ... 592,256
PC DOS 6.30 ... 593,024
PC DOS 7.00 Revision 0 ... 593,840
PC DOS 2000 (7.00 Revision 1) ... 593,760

I also have an MS-DOS 4.01 boot disk, but not a copy of CHKDSK which will work with it, so I can't give it an accurate free RAM amount, but judging by what other utilities report, it's somewhere in the ballpark of 590,000 bytes. So IBM claimed that PC DOS 7 offered the most free RAM of any version of DOS since 3.3, and that does appear to be true!"

subrosian
March 5th, 2017, 10:00 PM
Wow, the thread was dead for days and it came to life over the weekend!

Unfortunately, I like MS Edit, so it wouldn't really work for me to move back to DOS 3.3 and ~1kb doesn't seem enough to worry about going higher than my 6.22. I purchased two AST Advantage cards on eBay, hoping one of them works. I read all of the stuff about needed 120ns ram chips and how to use them to top off my 640K, and using the rest above 1MB. Getting more ram seems like the best approach, which I guessed from the beginning.

Also, I have tried messing with cutemouse, but it isn't working right in my first tests. I will try again later though.

The cards will be delivered in a week or so, so I will update then. Thanks everyone for your info.

Trixter
March 7th, 2017, 11:58 AM
Also, I have tried messing with cutemouse, but it isn't working right in my first tests. I will try again later though.

I've found that the earlier versions (1.9x IIRC) are more compatible with earlier systems, so maybe try that. It's still available at the cutemouse website.