IBM PC AT CMOS Battery Trouble

[Chuck(G)]

i think i might need to clean the floppy drives in my ibm at because they leave some dust on my disks when i take them out and sometimes i have to blow inside of the drive to get the floppies to read, could someone maybe send me a link to a tutorial about cleaning an ibm at's floppy drives? thanks.

Yes, the power supply fan keeps the case at a negative pressure with respect to the outside, which means that dust gets sucked in through the floppy slots.

I'd first try the minimum--just blow the dust out of everything with some low-pressure compressed air. As long as the dust hasn't caked onto the heads you should be okay. Otherwise, you'll want to moisten a cotton swab (Q-tip) in some denatured alcohol and gently wipe the space between the upper and lower heads. Or you can use a cleaning disk for your drive, but those are pretty scarce nowadays.

 

[risko404]

thank you for your help Chuck(G) i really appreciate it. i was able to set the hdd to type 2 and when i booted up without a floppy it read off the hdd and amazingly still had dos 3.30 on it. i still get setup error 162 and was wondering if you could tell me what else i have to do to get this computer to boot up without any errors. i haven't setup the floppy drives in gsetup because i don't know which floppy drive is 360k and which one is 1.2mb. can you tell me which one is which and so i can give gsetup the information.

 

[modem7]

The floppy drive with the 'asterisk within circle' is an IBM 360K drive (that's how IBM marked the 360K drives after the 5170 was released).

The 162 error is probably there because of a configuration mismatch. For example, when you ran setup, you may have informed the setup program that the 5170 has 640K of base memory, but on boot, the 5170 is finding 512K. Or perhaps it is because you've yet to set in the floppy drive types.

If you are unsure about the amount of 'base' and 'expansion' memory to enter into the setup program, run the DOS program in http://members.dodo.com.au/~slappanel555/misc/MEMSIZE.zip on your 5170. It will inform you as to what is fitted.

 

[risko404]

thanks for all your help Chuck(G). i finally got it to work. i was able to get the correct drive configuration into the setup program, the correct memory amount, (512kb onboard, no expansion cards) and when i saved it and left the pc off for awhile, and turned it back on the settings where still saved in the cmos and it booted up perfectly from the hdd. i even installed tetris on it though to play other games i'm gonna need a cga monitor which i don't have unfortunatley, luckily there is a guy i know who is looking for one to sell me. anyway, thanks again for all your help, and by the way, do you know of any word processor software, spreadsheet software, or monochrome games that i could download and install on this computer? thanks.

 

[modem7]

and by the way, do you know of any word processor software, spreadsheet software, or monochrome games that i could download and install on this computer? thanks.

Do an Internet search using "dos software". There's lots of of it out there.

as i said before, i have a full height 5.25 hard drive, the sticker on it says it has a capacity of 20mb,

IBM would put a sticker on the front of the drive that included the drive type number in large format, not the drive capacity. Was that "20mb" you quoted "20" instead? If so, then you probably have a 30MB sized drive of type 20, and accordingly you would set type 20 into the CMOS/RTC setup program.

Set the drive type per the drive's make/model per:
Seagate ST-4026 = type 2
Seagate ST-4038 = type 20
IBM 0665-38 = type 20

 

[vwestlife]

I'll have to verify when Microsoft got religion. I suspect the old way still obtains with DOS 4.0, but changes at DOS 5. I'm surprised that they didn't do it at DOS 2.0, when they undertook "the great Xenix-ification" of DOS.

DOS 2.x could've been even more UNIX-like, as hinted by some of the undocumented commands for it. Quoting the list which I compiled, and had published in DOS World Magazine in 1996:

AVAILDEV
Syntax: AVAILDEV=TRUE or AVAILDEV=FALSE
Default: AVAILDEV=TRUE

This commmand controls the access to devices. Usually devices are
accessed by name (e.g. CON or LPT1). This behavior might be undesirable
however if the user decides to use a device name as file name. AVAILDEV
has been removed from DOS version 3.0 and higher so that there is no
ambiguity when accessing a network. If CONFIG.SYS contains the command
AVAILDEV=FALSE, the access to devices is only available using a
non-existent file in the non-existent directory \DEV. For example, the
device COM1 could be accessed as \DEV\COM1.

And:

SWITCHAR
Syntax: SWITCHAR=char
Default: SWITCHAR=/

Until DOS 3.0 you could select the character that has to precede each
switch. You could use the UNIX-style command syntax when using "-" as
the switch character instead of "/". There is a DOS system function
(Int 21h, function 37h, subfunctions 0 and 1), undocumented until DOS
3.0, to get or set this switch character. Not all commands in all DOS
versions did actually support this feature. That the reason for the
removal of this option is the growing use of network software, where a
selectable switch character would cause problems.

 

[Chuck(G)]

Yeah, I've got the MS-DOS 2.00 OEM release notes. MS comes right out and says that the object of the new features is to make MS-DOS more Xenix-line and that eventually the two will be the same. Never happened.

There's documentation a plenty that documents the system calls for those options, BTW. The right way to decipher a command line was to first get the switch character from the system, then parse the command line with it. Darned few programs actually did that--most just hardwaried it in.