View Full Version : IBM PS/2 Model 50Z 8550 "Error in EXE File" & how to open case?

February 4th, 2014, 05:35 AM
Got the really cool IBM PS/2 Model 50Z 8550 that I bought from Chromedome45 yesterday. I installed MS-DOS 6.22.

2 questions.

1: "Error in EXE File" shows up a lot. When I copy files from / to HDD & FDD via FDD and/or LapLink this error pops up. Is this a HDD, I/O bus or some other issue(s)?
2: How do I open up this machine? I just want to have a look inside and make sure cables are not disconnected / squeezed after shipping.

Thanks! :D

February 4th, 2014, 05:48 AM
I believe the 50Z is just 2-3 screws on the back panel, and slide the outer shell toward the front of the machine.

The 50Z (unless someone modified yours) has a HDD that plugs directly into a riser board, no cable. I suppose the riser could have been jarred in shipping though...

February 4th, 2014, 08:14 AM
Managed to open the case. Everything looks fine and connected. Booting in IBM PC DOS 5.0 the system appears to work. Booting in MS DOS 6.22 the system appears to have this weird issue.

February 4th, 2014, 04:07 PM
Don't miss watching John Dvorak attempt to disassemble and re-assemble a PS/2 on live TV. It's one of the most memorable moments from Computer Chronicles, beginning around 14:19 in this video:


February 5th, 2014, 11:17 AM
Cool! Thanks! :)

BTW: the system still has issues.

February 5th, 2014, 12:47 PM
BTW: the system still has issues.
For various problems to go, you will need to run IBM DOS, and load the last version of IBM's DASDDRVR.SYS
DASDDRVR.SYS gets around certain BIOS bugs.

The fourth edition of the 'Upgrading and Repairing PCs' book lists the DASDDRVR.SYS fixes for the 8550 as:
* Failures occur in reading some 720K program floppy disks
* Intermittent Not ready or General failure error messages appear
* 3 1/2-inch floppy disk format fails when user tries to format more than one floppy disk
* Combined 301 and 8602 error messages appear at power-on or after power interruption
* System clock loses time, or combined 162 and 163 errors appear during system initialization
* System performance degradation occurs from processor intensive devices

February 5th, 2014, 03:59 PM
Thanks! Let me get a copy of IBM DOS and take it from there. :) It turns out there was / is a virus on the machine. I am working on cleaning it. Trojector.1561 is the virus recognized by F-Prot.

February 5th, 2014, 04:39 PM
More information on DASDDRVR.SYS is [here (http://www.minuszerodegrees.net/ps2/DASDDRVR.SYS.pdf)].

February 5th, 2014, 05:03 PM
Cool. Thank you very much.

Update: the machine works flawlessly so far after FDISK / FORMAT. I will still install IBM DOS and the SYS file. :)

February 5th, 2014, 06:33 PM
If you want to double check the hdd for any more virus http://ibm-pc.org/utilities/v-scans/v-scans.htm

February 6th, 2014, 04:24 AM
Excellent. I will try that this weekend. I have been using a 2004 F-PROT. My 2014 Kaspersky also picks up viruses on diskettes. I am going to check all those. The big question will be whether I will have 5.25" diskettes with viruses.

February 6th, 2014, 04:40 AM
I'd guess the virus is on your 6.22 boot disk. This is easily preventable by using write protect tabs. :-)

February 6th, 2014, 04:46 AM
It was on the 50Z and then spread. So far all diskettes not used on the 50Z came back clean. My ValuePoint was infected because I copied files across from the 50Z. So I FDISK / FORMAT treated that desktop as well yesterday evening. The nice thing about installing DOS is that it is lightning fast. :)

February 6th, 2014, 09:55 AM
C'mon having virus is all part of the Dos experience:)