Bec got me an IBM 5150 PC for Christmas! In this video, I swap out the MDA video adapter for a VGA adapter and test it out.
Here’s some details discussed/discovered in the video:
Since I don’t have an MDA monitor, I install an 8-bit Western Digital PVGA1A-JK based video card. (Thanks to user KD5VMF for his/her knowledge of the video card dip switches posted here on the Vintage Computer Forum: http://www.vcfed.org/forum/archive/in…) Also of note and not shown in the video is that I had to set SW1 switches 5 and 6 to “On” in order for the VGA card to work.
I also discover the computer has an NEC D8088D CPU installed instead of the stock Intel CPU. This is odd because the two are functionally identical. The original CPU may have went bad but I guess we’ll never know.
IBM DOS and the 5.25″ Floppy Drives
I boot the machine with IBM DOS 3.21 and IBM DOS 3.3. The IBM-branded “A:” drive works. The “B:” drive does not. An attempted repair video will be forthcoming.