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IBM 5170 + Memory Card = No Floppy Boot

S

SpidersWeb

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Feb 16, 2012
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This is odd and I'd love to hear some theories.

If I have:

- Video
- Floppy Controller

It boots off floppy fine. But add my Everex 3000 (setup to provide 128KB base memory and 2.5Mb extended) and it wont boot anything newer than DOS 3.3 from the floppy drive.

DOS 6.22 or DOS 5.0 on either 360K or 1.2Mb disks will not boot. In DOS 6.22 it gets to the point just before "Starting MS DOS" and you hear the drive go back and forward like it has a bad sector then you get a Non System Disk Message. DOS 5 just hangs, 3.3 boots fine and so does the AT Advanced Diagnostics disk. (NB: I tested these disks in other machines, created new ones, changed controller, changed cables, tried changing floppy drive - the symptoms are exact and go away completely when the memory card is removed)

It boots DOS 6.22 off a hard drive no problem - and you can access/copy files from/to floppy without a problem - you just can't boot DOS 6.22 off floppy without removing the memory card.
For everything other than booting modern DOS versions off floppy - it's perfect.

Ideas?
Board is an IBM 5170 Type 2 8Mhz. Memory card is an Everex EV-135 3000 AT RAM Deluxe.
 
Are there any high memory arguements in your config.sys?

What video are you using? If it's VGA try a lesser type, e.g., EGA or CGA.

Does the memory card fill the area from 640K to 1M and if it does can you set it to exclude this area?
 
VGA - tried two different cards. They're working reliablyand it's also booting fine if I use a hard drive.

The Memory card is set to fill 512-640KB and the rest starts at 1024Kb.
There is an extra 128KB that gets lost when doing this, however I haven't had any problems with Option ROMs including VGA. e.g. I can play games, boot off a hard drive, use a SCSI controller etc so I'd expect the card has locked this off or I'd be getting weird issues with each.

CONFIG.SYS is empty but it doesn't get that far, I don't even get "Starting MS-DOS...."
Remove memory card, and it boots off floppy fine.

Now that I have DOS 6.22 loaded on the hard drive, I've put my extra cards back in. So it has ESDI (cheers!), SCSI, VGA, and memory board and working fine. But if I ever need to boot from floppy in the future, I have to remove that memory card.

I did wonder, if it was possible that DOS 3.3 loaded low in memory and DOS 5 / 6.22 load themselves in to that 512-640 range? Perhaps DMA floppy -> memory card has a problem??
 
I just went and did some more playing with it now.

Had it write it's own system disk and it was fine.

The odd thing was I tested my disks booted, and tried a different drive on the 5170 too, problem is always in the same spot (appears to be ~track 8 ) and it only happens with the memory card in :S
 
Ahhh... the old bad floppy syndrome rears its ugly head, again! :) I routinely test all my 5.25" floppies with either Disk Test or Norton Disk Doctor, both of which are able to reveal questionable if not bad sectors. Those are tools which I would categorize as way more valuable now then they were 20 - 25 years ago when they were relatively new as were the floppy disks they were being used on. Now that the disks themselves are relatively old the tools are performing the service for which they were ultimately designed.
 
GottaLottaStuff said:
Could be the power supply is getting weak and can't quite handle the RAM card's extra load. Might make something a little hit-or-miss in the floppy drive. :)
Click to expand...

Yeah I was wondering that as well. I should check those voltages (and if I had a scope, how clean they are).
It's not the original PSU btw, it's an XT PSU case with the board removed with an L shape cut in to it, and a 486 PSU board fitted inside (250W I think) - but I haven't measured it's stability yet.

Machine is running great now, but I suspect the floppy issue still exists, I'm transferring files with a Syquest drive at the moment so haven't really been testing it further.
 
Tested voltages, they were within range but on the higher side, no signs of drooping.

But anywho, moved the memory card to another slot and now my floppy problems are gone.
But I've been through a few video cards.

1Mb Trident - no problems - except this is meant for my 486 ISA board not the 5170 - my AT doesn't need 32bit video memory or VESA support :p
512K Realtek - runs OK except when a DOS program closes one page, and goes back to a previous without redrawing (in which case it becomes corrupted)
512K Trident - no funny colours, but will crash if you scroll text at the dos prompt
2 x 512K WDC VGA16 - same as above, immediate system crash on scroll

All of this completely goes away when I remove the memory card (I retested all cards).
But I found something new, if I disable the 512-640KB memory fill on the Everex - success!

So 512KB conventional and 3Mb XMS with no dramas at all - except most the software I want to run bails out demanding more memory :(
I've been over the card settings 100 times, it certainly supports wasting 512KB (two banks of 41256 chips) on 128KB of conventional, but it must be leaking over in to the video RAM space.
Perhaps this was on purpose - for upper memory - and being from 1985 it's expecting something simple like MGA or CGA? (Stone mentioned this right at the start - think he could be right here)

As for disabling/excluding this area, there is nothing in TULARC but there is undocumented jumpers. I wonder if there is something in the manual, which appears to have gone missing from the internet a long time ago. I used the wayback machine and found EV135.EXE but it wasn't cached - and google didn't show anything with that filename.

So if anyone has a 128KB RAM card for sale :p
Oh and this machine needs to be VGA because I have MDA and CGA machines already, and I'm more likely to find a cure for aids than I am an EGA display in NZ.
 
SpidersWeb said:
But I found something new, if I disable the 512-640KB memory fill on the Everex - success!

So 512KB conventional and 3Mb XMS with no dramas at all - except most the software I want to run bails out demanding more memory :(
I've been over the card settings 100 times, it certainly supports wasting 512KB (two banks of 41256 chips) on 128KB of conventional, but it must be leaking over in to the video RAM space.
Perhaps this was on purpose - for upper memory - and being from 1985 it's expecting something simple like MGA or CGA? (Stone mentioned this right at the start - think he could be right here)
Click to expand...

That is strange. I also have a Everex EV-135 in my 5170AT with 3 MB of ram, configured as 128 KB Conventional + 1 MB EMS + 1920 KB XMS and I have no problems at all. I use a ATI VGA Wonder in that machine and it works as expected, also both HD floppy drives (5 1/4 and 3 1/2)
 
Stone said:
No, but I have a 256KB card.
Click to expand...

I'll keep that in mind, I'm figuring you can set it to 128KB only?
I've got a 512KB card but the highest you can set the start point is 256K (came out of an XT clone with 128KB on-board).

Anywho in the mean time, I have a solution. I've installed an AST SixPakPlus that was destined for an XT and set the memory to 128KB starting at 512KB. This is overkill and only 8 bit but now I have 640K + 3072K XMS and I can scroll all I like with any of my VGA cards. The only odd thing now is that if I leave it at the command prompt too long sometimes it hardware locks - but you can leave it running checkit, or playing a game and it never halts, so I'll just ignore that little annoyance for now.

As it is:

IBM 5170 8Mhz 512K
AST SixPakPlus 128K
Everex EV-135 AT RAM Deluxe V2.0 3072KB
WD VGA-16 256KB VGA
ESS AudioDrive
Adaptec 1542CF SCSI controller
Ultrastor 12F24 ESDI controller (thanks Stone! This card worked great!)
Syquest SQ555 - 44Mb removable cartridge
Miniscrime 9380E - 380Mb ESDI (320Mb formatted)

Beefy little guy. Usually I like to keep my IBM's 'authentic' but this one was already a 'hack job', so thought I'd make it as awesome as possible.
Having 300+Mb means I can load quite a lot of games on here. It's doing great for platform titles, I've been playing BioMenance.
 
nestor said:
That is strange. I also have a Everex EV-135 in my 5170AT with 3 MB of ram, configured as 128 KB Conventional + 1 MB EMS + 1920 KB XMS and I have no problems at all. I use a ATI VGA Wonder in that machine and it works as expected, also both HD floppy drives (5 1/4 and 3 1/2)
Click to expand...

Maybe mine is faulty.
I also discovered if I set it to 128KB conventional, but no extended, the problem goes away. It's only when I ask for both conventional and extended.

Mine is marked "Revision C00' but in TULARC it matches the VERSION 2.0 card.
 
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