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Hot rodding an IBM PC/AT

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Floppies_only

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Gang,

I got my IBM model 5170 off of ebay. I tried to get the seller to pack it in bubble wrap but he thought he knew everything and didn't. The hard drive (working when he took pictures of the system) makes this weird plinking sound when I start the computer and then the POST gives a 1790 error. I'm taking it that that and the fact that I read that the drives IBM used in the AT were notoriously unreliable means that I don't have to feel guilty about upgrading it with non-IBM parts.

I've got a 386 baby AT motherboard with 8 megs of RAM and I won auctions for an IDE hard drive and controller / I/O card. The hard drive has a 3 1/2" to 5 1/4" adaptor so it should slide right in.

What I was wondering is what is the best way to make Windows 3.1 run faster with this setup? I had a 286 clone before that I put 8 megs of RAM into and set up a RAMdrive and I think I used it for my /temp directory. But I don't have a RAMdrive utility now, unless one comes with DOS v. 6.22. Should I just not worry about it and let Windows use as much memory as it wants?

Thanks for any help.

Sean, who has wanted to upgrade a 5170 to have a "sleeper system" for quite a while - don't let the oldstyle EGA monitor fool you: I want my star field simulation to be running at warp six :)
 
Generally, Microsoft suggested staying away from RAMdisks, although I suspect it matters what kind (LIM EMS might do some good, actually) with Windows 3.x, claiming that the memory could be better put to use by Windows.

But I'm a bit confused. Are you running Windows 3.1 on a 286 or 386 system?
 
Don't swap out the motherboard, that's just not right. Instead just replace the MFM setup with the IDE drive and controller from your 386. I also recommend upgrading to the AMI BIOS, and overclocking to 8MHz if you have a 6MHz model.
 
I'm with AC--keep the 5170 mobo and "hotrod" it the way they did back in 1986--by replacing the CPU crystal with higher frequencies until the timing wouldn't hold together--some folks also used heatsinks on the 80286 chips. The original overclockers.
 
Chuck(G) said:
But I'm a bit confused. Are you running Windows 3.1 on a 286 or 386 system?
Click to expand...

Chuck,

I haven't managed to run Windows at home yet. The computer arrived all busted up and I've won parts to get it going from ebay. I plan to put a 386 motherboard in the case and run Windows with that. I would have just read the manuals but my copies of Windows are still in the shrink-wrap. I have this "issue" with taking the shrink-wrap off for some reason. I've got several software packages that are still sealed. But when I get the computer working, the wraps come off :)

Sean
 
Anonymous Coward said:
Don't swap out the motherboard, that's just not right.
Click to expand...

The clock doesn't keep time. I checked it after a couple of hours and it thought that only like an hour and a half had passed. I thought that might be because the battery was low. Also I doubt my ability to get enough RAM to make a 286 run windows as fast as I'd like. Bigdmclean wants $149.95 for an expansion board with two megs on it.

But I bought some large anti-static bags and I'll store the 286 motherboard for historical purposes.

Sean
 
i had windows 3.1 running on my 286 with only 2mb of memory. i think it would even run with only 1mb of memory.
 
Floppies_only said:
The clock doesn't keep time. I checked it after a couple of hours and it thought that only like an hour and a half had passed. I thought that might be because the battery was low.
Click to expand...
Yes. In an IBM 5170, loss of time is the first symptom of a low battery. As the battery voltage gets lower, the amount of time lost increases.

Measurements that I've done indicate that the actual battery voltage at which time loss starts to occur varies from motherboard to motherboard, and can be high as 3.7 volts. Refer http://members.dodo.com.au/~slappanel555/misc/5170_battery_3.6v.htm
 
Floppies_only said:
The hard drive (working when he took pictures of the system) makes this weird plinking sound when I start the computer and then the POST gives a 1790 error.
Click to expand...
The 1790 means that the controller test passed (a crude test) and that the drive responded okay to the POST issuing a 'recalibrate' command, but then there was a failure when the POST made an attempt to read certain sectors. The 1790 error can be caused by many things, but if the seller is adamant that the machine was booting from the hard drive, then one possible cause of a 1790 is that the data cable has fallen off the rear of the drive in transit.

Floppies_only said:
I'm taking it that that and the fact that I read that the drives IBM used in the AT were notoriously unreliable means that I don't have to feel guilty about upgrading it with non-IBM parts.
Click to expand...
It was only the first supplied drive model, the CMI model 6426-S, that was 'notoriously unreliable'.
 
There's not a lot that a ramdisk can do for Windows 3.1. Redirecting c:\temp to the ramdisk helped a little, but generally you got a bigger benefit from running as large of a disk cache as possible. The other thing you could do was to make a huge ramdisk (big enough to hold c:\windows) and run Windows from there. I tried that out of curiosity, years ago, but you really needed 64 meg of RAM (or more) for it to all fit, which pretty much requires a 486 or Pentium to do.

What I would do is install an IDE controller with a compact flash card in your AT. It won't be quite as fast as a ramdisk, but close, and you'll have tons of capacity then. You'd get most of the throughput of RAM and seek times nearly as good. And you won't beat a compact flash card's reliability, of course.
 
My 'Sleeper AT'

My 'Sleeper AT'

Out of necessity in 1993 I swapped the motherboard out of my original 6Mhz AT and replaced it with a 386-40 with 128K L2 cache. I left all of the original peripherals on it. So while the CPU was impressive, it was still fairly badly hobbled by the 20MB ST 225 and the STB EGA video card.

Today it's my main DOS development box - more of a sleeper in an old AT case than a 286 hotrod. The 384-40 is still there, but it had a 1.2GB IDE drive, VGA, and of course Ethernet now. I need to pull the IBM 'Cluster Adapter' out sometime - I haven't touched it in years. ('Cluster' is an ancient proprietary networking technology from IBM that slightly resembles Ethernet.) One handy upgrade has been a reset button mounted on a card bracket in back of the machine - perfect for the occasional time when I 'wedge' the machine in a tight loop.

The other 'sleeper' is my 486-66 in an old AT case. VL bus 2MB video card, VL bus SCSI controller, 4GB SCSI drive, and some other funnies.

'Hot rodding' implies that you are going to keep the 286 in the machine, and just option it out - as much memory as you can get, VGA, Ethernet, IDE, etc. But it still has to be a 286. Otherwise, you are building a 'sleeper' - a fast machine in an old case.

(And here we are at the funny nexus of where cars meet computers.)


-Mike
 
modem7 said:
The 1790 means that the controller test passed (a crude test) and that the drive responded okay to the POST issuing a 'recalibrate' command, but then there was a failure when the POST made an attempt to read certain sectors. The 1790 error can be caused by many things, but if the seller is adamant that the machine was booting from the hard drive, then one possible cause of a 1790 is that the data cable has fallen off the rear of the drive in transit.
Thanks for the info. I'll check the cable, but one thing I noticed was that the drive made the sound several times, as if the computer were trying to access it again and again, before it gave up.

Sean
Click to expand...
Click to expand...
 
Dave Farquhar said:
What I would do is install an IDE controller with a compact flash card in your AT. It won't be quite as fast as a ramdisk, but close, and you'll have tons of capacity then. You'd get most of the throughput of RAM and seek times nearly as good. And you won't beat a compact flash card's reliability, of course.
Click to expand...

It's a question of whether I can get the hard drive cable to go from the nearest slot, where the compact flash drive plugs into the back of the computer, and the IDE drive in the left bay. I'm hoping I can.

Sean
 
mbbrutman said:
'Hot rodding' implies that you are going to keep the 286 in the machine, and just option it out - as much memory as you can get, VGA, Ethernet, IDE, etc. But it still has to be a 286. Otherwise, you are building a 'sleeper' - a fast machine in an old case.

(And here we are at the funny nexus of where cars meet computers.)


-Mike
Click to expand...

[Grin] Thanks for getting my terms straight :)

Sean
 
Dave Farquhar said:
There's not a lot that a ramdisk can do for Windows 3.1. Redirecting c:\temp to the ramdisk helped a little, but generally you got a bigger benefit from running as large of a disk cache as possible.
Click to expand...

I couldn't find any information on a disk cache in this forum. Wikipedia said that DOS has a RAMdisk since version 2.0. Does Windows come with a cache?

Thanks,
Sean
 
Floppies_only said:
I couldn't find any information on a disk cache in this forum. Wikipedia said that DOS has a RAMdisk since version 2.0. Does Windows come with a cache?
Click to expand...

Both do. ramdrv.sys is the ramdisk, smartdrv.exe is the cache. Use the one from DOS (in the c:\dos directory) if you're running 6.22. If you're running DOS 5, use the one that comes with Windows (in the c:\windows directory).
 
Dave Farquhar said:
Both do. ramdrv.sys is the ramdisk, smartdrv.exe is the cache. Use the one from DOS (in the c:\dos directory) if you're running 6.22. If you're running DOS 5, use the one that comes with Windows (in the c:\windows directory).
Click to expand...

Thanks Dave. I've got DOS v. 6.22, but I still have to get the manual for it. Just a matter of time.

Sean
 
I may still have a DOS 6.22 (or at least 6.2) manual. I'll look tonight. But I remember not being impressed with it. The DOS 5 manual was much better and still applicable. So I continued to use my DOS 5 manual for the rest of my DOS days.

Depending on your comfort level with DOS, you might do well to pick up one of the third-party books on DOS. I know the Dummies books are overrated, but DOS for Dummies was a very good book. It launched that franchise. You can pick up a used copies off Amazon for 4 bucks (a penny for the book, $3.99 shipping). You may still want a DOS 6.22 manual just to have it, but you'll probably want a better book when you need to look up how to actually do something.
 
Right now there are two AST Rampage 286 2M expansion boards on ebay for about $10 + $13 shipping. Though they are unpopulated. You can probably get populated boards for that price or less if you are patient. Last year I was trying to sell similar cards (populated) in that price range and could find no buyers.
 
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