smbaker
Experienced Member
I bought a 5150 off ebay last week, I think I got it for a reasonably good deal. It was in "powers-up" condition, which in eBay-speak often doesn't mean a whole lot. That's fine, as I'm always looking for a project. When powered on the first time, there's no visible or audible indication of anything happening, other than the fan spinning at what seems to be a normal fan speed. I haven't checked PSU voltages yet, i'm going to check PSU voltages today after work.
I pulled the installed video card and installed a known-working-in-8bit VGA card. A few more attempts didn't boot, but finally I did get a boot that had one long beep and two short beeps followed by the VGA BIOS displayed on screen. I was able to reproduce that a few times. The beeps were likely due to SW1 being configured for MDA while I had installed a VGA adapter. However, after correcting the switches (and putting them back to the way they were several times), I haven't been able to reproduce this success. No beeps. No VGA output.
My plan is to follow the diagnostics at minuszerodegrees.net, but I had a few questions.
First, the video card this thing came with says "Video-7 1985" on the back. It has a MC6845P. There's a single 9-pin female din. No composite connector. It has an onboard 2732. Can someone confirm whether this is a MDA adapter, or something else? ETA: FCC ID is D2A62LMGA, leading me to believe it is monochrome.
Second, I've ordered an adapter so I can burn a 26xx diagnostic ROM and put it on the motherboard in place of the BIOS. My understanding is these diagnostic ROMs work with MDA, CGA, and sometimes EGA, but definitely not VGA. That means if I want to go that route I'm going to have to find some way to convert MDA or CGA into something I can view on a modern LCD. I got rid of my last multisync monitor a decade or two ago. Any suggestions on the best way to do this? Should I just buy on eBay a CGA card that has composite output?
Thanks,
Scott
I pulled the installed video card and installed a known-working-in-8bit VGA card. A few more attempts didn't boot, but finally I did get a boot that had one long beep and two short beeps followed by the VGA BIOS displayed on screen. I was able to reproduce that a few times. The beeps were likely due to SW1 being configured for MDA while I had installed a VGA adapter. However, after correcting the switches (and putting them back to the way they were several times), I haven't been able to reproduce this success. No beeps. No VGA output.
My plan is to follow the diagnostics at minuszerodegrees.net, but I had a few questions.
First, the video card this thing came with says "Video-7 1985" on the back. It has a MC6845P. There's a single 9-pin female din. No composite connector. It has an onboard 2732. Can someone confirm whether this is a MDA adapter, or something else? ETA: FCC ID is D2A62LMGA, leading me to believe it is monochrome.
Second, I've ordered an adapter so I can burn a 26xx diagnostic ROM and put it on the motherboard in place of the BIOS. My understanding is these diagnostic ROMs work with MDA, CGA, and sometimes EGA, but definitely not VGA. That means if I want to go that route I'm going to have to find some way to convert MDA or CGA into something I can view on a modern LCD. I got rid of my last multisync monitor a decade or two ago. Any suggestions on the best way to do this? Should I just buy on eBay a CGA card that has composite output?
Thanks,
Scott
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