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lutiana
September 12th, 2017, 09:10 PM
So I have this card: http://th99.classic-computing.de/src/i/I-L/55275.htm and I have it set for drive A to be a 1.2/1.44Mb drive in a 8086/8088 machine and installed in an IBM 5150 (the 64-256kb version of the 5150), but I cannot get it to boot from a 1.44Mb DOS 6.22 disk. It does the drive seek, then goes to boot from the disk and just hangs there with the floppy light on. I have a second BIOSed floppy drive (a KW something else, cannot recall at the moment, but it is a different model) and that one does the same thing.

Any suggestions on what it is I am doing wrong? Could it be a problem with the 5150 BIOS (not sure what revision is in the machine).

My next step here is to try the cards in one of my 5160s and maybe one of the other 5150s I have. But I won't have time to do this till the weekend, so I figured I'd ask here in the mean time.

Chuck(G)
September 12th, 2017, 09:27 PM
I wonder if the BIOS is being seen. Does it display any sort of identification on the boot screen?

Have you tried booting from a 720K floppy?

lutiana
September 12th, 2017, 09:46 PM
I wonder if the BIOS is being seen. Does it display any sort of identification on the boot screen?

The second card I tried does display a BIOS message, the first does not. However I think the first did work in the 5160 when I tried it awhile back, but also did not display anything (I need to re-test this).


Have you tried booting from a 720K floppy?

I have a 720kb boot disk sitting near the 1.44mb one, but I cannot for the life of me remember if I tried it. I'll give it a go tomorrow when I get home.

I should also mention that I did try a different known good floppy drive. So I am sure it's not the drive.

Malc
September 12th, 2017, 10:37 PM
The last Bios revision 10/27/82 for the 5150 added support for adapters with ROM BIOS extension, So you got the right bios if you see a bios message, If you can boot from a 720k DOS 6.22 floppy, Stick MSD on the floppy and run it, See what is listed for the floppy drive's, It probably see's them as 360k. Do you have a hard drive in the 5150 also ?

lutiana
September 12th, 2017, 11:11 PM
The last Bios revision 10/27/82 for the 5150 added support for adapters with ROM BIOS extension, So you got the right bios if you see a bios message, If you can boot from a 720k DOS 6.22 floppy, Stick MSD on the floppy and run it, See what is listed for the floppy drive's, It probably see's them as 360k. Do you have a hard drive in the 5150 also ?

I don't think the KW-530 has a BIOS message, I think it is just designed to do it's thing silently. No, there is no HDD in the 5150, but I will see if I can get it to boot off of something and tell me what the floppy specs are, and if it can read a 1.44Mb disk even if it can't boot from it.

modem7
September 13th, 2017, 12:39 AM
Could it be a problem with the 5150 BIOS (not sure what revision is in the machine).
Yes it could, as Malc wrote.
First thing to do is verify that you have the 10/27/82 revision - see [here (http://minuszerodegrees.net/5150/bios/5150_bios_revisions.htm)].

lutiana
September 13th, 2017, 01:11 AM
Yes it could, as Malc wrote.
First thing to do is verify that you have the 10/27/82 revision - see [here (http://minuszerodegrees.net/5150/bios/5150_bios_revisions.htm)].

Yes, the part number matches the latest BIOS chip listed there though it does look different from the one you have pctured on your site.

Just out of curiosity, there are 5 ROM chips on this board, one is the main BIOS and I assume 2 are for BASIC, but what are the other 2 for? And given there is one free ROM socket, could I put floppy BIOS on a ROM chip in that socket and just use a non-biosed HD floppy controller?

modem7
September 13th, 2017, 01:49 AM
Yes, the part number matches the latest BIOS chip listed there though it does look different from the one you have pctured on your site.
During the supply lifetime of the 5150, IBM had different manufacturers make the ROMS. Some examples at [here (http://minuszerodegrees.net/images2/1501476.jpg)].


Just out of curiosity, there are 5 ROM chips on this board, one is the main BIOS and I assume 2 are for BASIC, but what are the other 2 for?
U33 = BIOS
U29/U30/U31/U32 = Cassette BASIC

That answer and much more is in the 5150 section of minuszerodegrees.net
It would pay for you to take a read.


And given there is one free ROM socket, ...
Yes, U28, per the diagram at [here (http://minuszerodegrees.net/5150/misc/5150%20-%20Memory%20Map%20of%20the%20640%20KB%20to%201%20M B%20Area.jpg)].


... could I put floppy BIOS on a ROM chip in that socket and just use a non-biosed HD floppy controller?
1. Yes, if the BIOS supports being based at address F4000
2. Note that the ROM sockets do not take 27xxx series EPROMs.

lutiana
September 13th, 2017, 07:28 AM
During the supply lifetime of the 5150, IBM had different manufacturers make the ROMS. Some examples at [here (http://minuszerodegrees.net/images2/1501476.jpg)].

Mine are the ones on the bottom left of that image. Seem to be made by AMI.




U33 = BIOS
U29/U30/U31/U32 = Cassette BASIC

That answer and much more is in the 5150 section of minuszerodegrees.net
It would pay for you to take a read.


I have explored that section extensively and have read a fair bit of what is on there.



Yes, U28, per the diagram at [here (http://minuszerodegrees.net/5150/misc/5150%20-%20Memory%20Map%20of%20the%20640%20KB%20to%201%20M B%20Area.jpg)].


1. Yes, if the BIOS supports being based at address F4000
2. Note that the ROM sockets do not take 27xxx series EPROMs.

Yes, I saw that there is an adapter that can be purchased and/or fabricated for the use of 27xxx EPROMs, and good to know on that base address, does Sergey's floppy BIOS run at that base address?

I am going to try and get to do some more testing tonight, I will try booting from the 720kb disk I have, and I will also try both floppy controllers in a 5160 as well as in another 5150 I have. Hopefully that will give me some further insight into this issue.

Malc
September 13th, 2017, 08:12 AM
....does Sergey's floppy BIOS run at that base address?....

Probably be ok, the only thing is you will have to configure the bios to suit your floppy drive setup before you burn the eprom because obviously the floppy config utility won't work. I never tried using that U28 free socket in my 5150 but i have used U19 in my 5160 with the 11/08/82 Bios to home the XUB and Sergey's bios before and it worked.

modem7
September 13th, 2017, 04:31 PM
I never tried using that U28 free socket in my 5150 ...
Neither have I, but, per note 3 at [here (http://minuszerodegrees.net/5150/post/5150%20-%20POST%20-%20Detailed%20breakdown.htm)], the 10/27/82 revision BIOS does scan the U28 address space for BIOS expansion ROMs.

lutiana
September 13th, 2017, 04:37 PM
Solved the issue. I was getting a 201 (memory error) at post, this was expected as there was only 256Kb of RAM in the thing and I had set it to 640 in anticipation of me installing a RAM card, so on a whim I thought let me just quickly get rid of that error and see what happens.

And boom, it now boots from 1.44Mb disks flawlessly. So apparently the RAM mismatch caused the BIOS on the controller to have some sort of issue. Odd as heck IMO.

Ok, onto the next step here, mounting a 1.44Mb floppy and woking out how to blank out the other bays. Then it's onto the XT-IDE build and install with a 256MB DOM...

lutiana
September 14th, 2017, 04:59 PM
Ok, I can't win with this machine. After my success with the floppy drive I decided to add in a memory card (384K to bring the system upto 640k). Well the card I tried first is bad, but not only did it cause the system to not power up, it fried one of my floppy controllers (not the KW-530, the other one). Seriously ticked about that, but anyways.

So I tried the second memory card I have, this time with nothing else the system, this one threw up some memory errors but the machine worked. After some digging around I worked out that this card is a clone of this card here (http://minuszerodegrees.net/manuals/MEMO576%20RAM%20Card%20-%20Users%20Guide.pdf) and the dip settings given in that manual worked for this card. It now does post successfully with no errors. Great right? Well except now that I have this card installed the machine won't boot from the floppy anymore. It gets as far as saying "Starting MS-DOS...." then just hangs. This is a 1.44Mb DOS 6.22 boot disk that works fine with no RAM card and the board set to just 256K of RAM. So then I tried the 720Kb floppy (also DOS 6.22 and works fine pre-ram card) and seems to try to boot, but then just drops into Basic.

Oddly basic says 62k of RAM free though, I am not sure if this is expected or not.

EDIT: Set the board back to 256K RAM and then pulled the RAM card, booting from DOS get's me a "PARITY CHECK 1" on the screen in large letters and that's all she will do now. There is no 201 error on post or anything. So I am stumped. Any suggestions?