IBM PC 5150 BIOS Versions

[ZOBEX]

[QUOTE=wdegroot;81470]the aim or every red-blooded american boy or man was to put a genuine IBM bios in his pc or xt..]

I was one of those red bloods. With a 4.77 xt and a NeedHams eprom burner I spent months using a program to suck out ever XT and AT bios I could find an built up a data base for lets say resale to customers wanting an upgrade. I would split and rematch across multiple eprom chips. Even rewrote some of the code for various projects. Some place I have a box full of 360k floppys just of snatched bios's.

Maybe I'll go looking for it.

[k2x4b524[]

hate to further bring back a dead post, but can one of those bioses be used to get an AT with 720kb support to support a 1440kb drive?

[modem7]

hate to further bring back a dead post, but can one of those bioses be used to get an AT with 720kb support to support a 1440kb drive?

In case you are unaware, 'partial' 1.44M support can be gained by the proper use of DRIVER.SYS (launched via CONFIG.SYS). The use of DRIVER.SYS won't allow the IBM AT to boot from a 1.44M diskette.

If you need the capability to boot from a 1.44M diskette, yes, you'll need an updated BIOS. The 11/15/85 BIOS for the IBM AT supports 1.44M drives. That BIOS is at at http://members.dodo.com.au/~slappanel555/bios.htm Also there is a suitable AMI and suitable Award BIOS for the IBM AT.

If you use the 11/15/85 BIOS, you may need to use something like GSETUP (at http://members.dodo.com.au/~slappane...are/GSETUP.ZIP) to then set 1.44M in the CMOS setup/configuration.

[mmruzek]

Question: The 10/27/1982 BIOS from IBM for the 5150 would be the logical choice for True Blue enthusiasts, but what after-market or clone BIOS for the 5 slot PC motherboard adds the most functionality? ( I have an EPROM burner and I know how to use it!) Would appreciate all inputs and points of view. Thank You, Michael.

[RuudB]

I interested, I made an ASM file of the 11/08/82 BIOS for the 5160. I already enhanced it for my self by speeding up the RAM test so one hasn't to wait 'ages' :) You're free to have the sources of these and other BIOSes to create one according your own taste. You only need the old Borland TASM V3.2 to create the BINs.

Groetjes, Ruud Baltissen
www.Baltissen.org

[hopper]

There's a lot of details about the three BIOS revisions here and in the wiki, but not much information about motherboard revisions. The wiki article only says that there were two hardware versions (16/64K "A" and 64/256K "B"), but it looks like there were several versions of each type. I have two 64/256KB 5150s and they have completely different motherboards.

The first is from November 1983 and has "1501480 XM" written on the motherboard. There is a space between the parity bit and Bit 0 for all four RAM banks.
The second is from October 1984 and clearly states "P/N 6137399". The is no space between the nine RAM chips in each bank.

1501480 XM and 6137399 seem like very different part numbers. Is there a list anywhere of part numbers for 16/64KB and 64/256KB 5150 motherboards?

[modem7]

Like myself, others have discovered that the 10/27/82 BIOS for the 5150 has a requirement for a minimum of four banks of motherboard RAM.
That requirement is contrary to IBM's documentation.
I've started reseaching why the requirement exists, and documenting the results at http://www.minuszerodegrees.net

[modem7]

The 10/27/82 revision of the 5150 BIOS has a bug related to XT-class hard disk controllers (if controller added).

If the ROM on that controller is corrupt (different from 'dead'), then instead of the error code of "C800 ROM" being displayed, there will be heard 1 long beep then 2 short beeps (which suggests an MDA/CGA video related problem).

Details at http://www.minuszerodegrees.net/5150...ialisation.htm

[fs5500]

Hi.

I found Revision 3 (10/27/82) version exists as 3 kinds.

1) BIOS with IBM BASIC C1.00 (BIOS - 1501476 COPR. IBM 1981 / Checksum : 00, value of FFFFh is 78h)
2) BIOS with IBM BASIC C1.10 (BIOS - 1501476 COPR. IBM 1981 / Checksum : 00, value of FFFFh is 78h)
3) BIOS with IBM BASIC C1.10 (BIOS - 1501476 COPR. IBM 1982 / Checksum : 00, value of FFFFh is 77h)

Of course they're dumped correctly.
I have all of them.

[modem7]

I found Revision 3 (10/27/82) version exists as 3 kinds.

1) BIOS with IBM BASIC C1.00 (BIOS - 1501476 COPR. IBM 1981 / Checksum : 00, value of FFFFh is 78h)
2) BIOS with IBM BASIC C1.10 (BIOS - 1501476 COPR. IBM 1981 / Checksum : 00, value of FFFFh is 78h)
3) BIOS with IBM BASIC C1.10 (BIOS - 1501476 COPR. IBM 1982 / Checksum : 00, value of FFFFh is 77h)

This is the third revision BIOS for the 5150. It is dated "10/27/82" in code, and has "1501476" printed on the top of the chip.

What fs5500 is bringing our attention to, is that there are two versions of the third revision BIOS for the 5150.

The difference is in the year that appears in the copyright string at the start of the ROM:
1. "1501476 COPR. IBM 1981"; or
2. "1501476 COPR. IBM 1982"

As expected, the checksum byte (last byte) in the ROM is different also.

To verify what fs5500 wrote, I inspected the eight 1501476 chips that I have access to.
Of those:
* Three are "1501476 COPR. IBM 1981" ones, and have "1982" printed on their top;
* Five are "1501476 COPR. IBM 1982" ones, and have "1981, 1983" printed on their top.