Ivory CPU Heatsink and Instability
One of the theories about the instability of my Symbolics XL1200 is that the CPU has no heatsink and so it is suffering from thermal problems »
XL1201 Moment of Truth
UPDATE: No joy. Still self-reboots. So, I put the Merlin II card back into the XL1201, connected the power and console, and powered it up. Nothing. »
XL1201 Merlin II Chip Reseating
UPDATE: I clipped and removed the broken capacitor. Replacing it will be the task of another day. I spent two days removing, cleaning and reseating each »
Detailed Inspection of XL1201 Merlin II Solder Side
To see if I can isolate the cause of the XL1201 instability, I am going to physically inspect the two main cards with a loupe and »
XL1201 Stability Update
In an effort to rule out the power supply causing the XL1201's instability, I sent it out for overhaul by Power Clinic. After reinstalling it, I »
Todd MAX-354-1252 Power Supply for XL1201
So, I learned something about the Todd MAX-354-1252 power supply in the Symbolics XL1201 today that I thought I'd share. Not that I understand it, mind »
More XL1201 Crashes
Well, tonight I had more crashes using the XL1201. Each time the computer crashed after about 20 minutes. This indicates to me that there's something odd »
XL1201 Instability Next Steps
Well, the instability on the XL1201 has been disheartening. However, I have a few suggestions and plans to see if I can figure it out. Kalman »
Power Supply, Memory, Crashes
I don't have the time to post all the details before going to sleep, but I did a few things tonight including measure the power supply »
Clean Genera 8.3 FEPfs
I was asked to provide a full list of all the files on the XL1201 Genera 8.3 hard drive I received from David K. Schmidt. »
Setting Up Genera 8.3, Part 1
I'm setting up Genera 8.3 on the XL1201 using a clean hard drive. Literally all this hard drive has on it is Genera 8.3 »
XL1201 Power Consumption
I was asked how much power is used by the XL1201. Here are a few data points... XL1201 with only SCSI2SD: 222-233W Console: 106W With the »
XL1201 and SCSI2SD v5 128GB
I'm attempting to use the SCSI2SD v5 with a 128G microSD card. You can find out the size of an SD card attached to a modern »
SCSI 50 to 68-pin Adapters
Well, it seems that not all SCSI 50-pin female to 68 pin female adapters are created equally. I bought several of these from Amazon, made by »
XL1201 Mini-benchmark
UPDATED July 28, 2016: More mini-benchmark results added. I was asked to do a simple benchmark of the XL1201 by Jerome Ibanes and share the results. »
XL1201 Known Working Disks
Note: After formatting a disk to 1280-byte blocks on Genera, make sure to hard power cycle reboot the computer before trying to use it for a »
Large SCSI Disks and XL1201
TL;DR: SCSI disks with 20M 1280-byte blocks work SCSI disks with 25M 1280-byte blocks work SCSI disks with 28M 1280-byte blocks work SCSI disks with »
Clean Boot of Genera 8.3
The XL1201 now boots nicely from a new ST318451LW Cheetah drive that David K. Schmidt sent (sold) me. It loads FEP version 333 and a clean »
Broken SCSI Pin on XL1201
Well, I was installing a new hard drive into the XL1201 today and just before I connected the SCSI cable, I noticed a pin seemed to »
Clean Install Genera 8.3 on XL1201
Attempting a clean install of Genera 8.3 on XL1201 using just a CD-ROM drive and a blank hard drive. However, from preliminary results, this seems »