• Please review our updated Terms and Rules here

Incomplete BOOT on my 5150 using Supersoft Landmark Diagnostic ROM

p.giaquinto

New Member
Joined
May 18, 2019
Messages
8
Location
Italy
Unfortunately my 5150 don't works, no beeps with minimum diagnostic configuration… no screen with full configuration.
I have burned a 2764 using Supersoft Landmark Diagnostic ROM image to try some diagnostics… it starts but the boot stops on U36 :-(
I have already replaced sa broken 8288 and I have tested all 4164 RAMs (4x64KB) on another working MB, a XT clone.
Please see the attachement, can you help me?? I hope, thank you very much.
Pino
 

Attachments

  • IMG_5421.jpg
    IMG_5421.jpg
    82.7 KB · Views: 3
That message should say "8255 PARITY DETECTED". Looks as if you have a possible video issue or an I/O conflict. You haven't even gotten to the motherboard memory check yet.
 
That message should say "8255 PARITY DETECTED".
Yes and it is incomplete and corrupted on display…why?
I tried to replace the 8255 with another working chip but I haven't solved :mad:

Looks as if you have a possible video issue or an I/O conflict.
My video card is a Hercules and works fine… I'm sure because I use it on my XT. I/O conflict?? Where I can investigate?

I tried using a Ruud DIAGROM also, but the boot is still incomplete, please see attachement.

Before the tests using the two diagnostic ROM I have made some controls on many signals using my original ROM (10/27/82), please see other attachement: there are some signals from my MB… some seconds loaded starting from Power On.
/IOW pulse for about 50ms then go UP forever, then after other 50ms ALE don't pulse anymore and stay DOWN.

I hope you can help me... :(
 

Attachments

  • IMG_5425.jpg
    IMG_5425.jpg
    103.8 KB · Views: 1
  • 2019-08-08 (3).jpg
    2019-08-08 (3).jpg
    21.9 KB · Views: 2
Back
Top