Symbolics on Symbolics LISP Engineering

Symbolics LAN - Overview

Sun, 09 May 2021 21:34:56 +0000

Over the past two weeks, I set up a small Symbolics LAN, and thought I would share some of the process and findings. I will write a post about each item, but the topics already concluded cover:

Performance challenges of the Merlin Ethernet under load, and modern 10Base5 to 10BaseT transceivers
An improvement to the stability of my first XL1201 which I was unstable, some five years ago
Y2k problems with the QFILE protocol under Chaosnet, and a “hotfix” to Genera’s QFILE client to bypass them (this is deprecated, but was fun to try out)
IP subnets and routing under Symbolics Namespaces
Setting up the three Symbolics XL computers as a small LAN with a Linux NFS server

Later, I hope to cover some more topics, including:

Symbolics XL LAN Challenges

Wed, 05 May 2021 22:26:17 +0000

I recently set up a LAN of my three XL Symbolics machines at home. The XL1201 which was having stability issues has been largely stabilized (thanks to help from David Schmidt). I will post more about this LAN soon, but I thought I would mention an interesting problem.

The machines connect to the LAN via an AUI to 10BaseT transceiver, to my core LAN which is a mixed 10G/1G LAN. The core router is a Ubiquiti EdgeRouter Pro which is attached to UNMS, their central management tool. When I connected these machines to the LAN, I was getting Merlin (the name of the CPU board) Ethernet errors on occasion, and eventually the computer would crash. I put the Symbolics computers on a separate segment connected only to a small Netgear switch and the EdgeRouter, but the computers kept crashing.

CLIM on Genera 8.3 [Updated]

Sun, 28 Aug 2016 18:55:07 +0000

In preparation of doing some actual software engineering on Genera, I decided to take a look at the CLIM implementation on my MacIvory III Genera 8.3.

There are a few steps to do first:

Load System CLIM: This will take a while. It loads a lot of files and several subsystems, including:
- Loading system CLIM version 66
- Initializing subsystem CLIM Utilities
- Initializing subsystem CLIM Silica
- Initializing subsystem CLIM Standalone
- Initializing system CLIM version 66
- Loading patches for system CLIM version 66
- Patches for CLIM (Current version is 66.3):
If you attempt to use CLIM at this point, however, it won’t work because there is no driver (in my parlance only, I’m not sure the official term). The example code will fail: Error: Cannot find port type: :GENERA
Load System Genera-CLIM will install the remaining parts

This whole process takes probably 15+ minutes of compiling and crunching, so you might want to save the world and restart after this (although I didn’t do this yet).

Ivory CPU Heatsink and Instability

Sat, 06 Aug 2016 14:13:58 +0000

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 after a while. (15-30-ish minutes)

David K. Schmidt was kind enough to send me an old heatsink. It’s 38x38x5 mm and has 11 fins on it, as you’ll see on the pictures; slightly smaller than the Ivory CPU itself.

First I cleaned the old epoxy from the heatsink using acetone, which was surprisingly easy to do.

Telnet to MacIvory

Fri, 29 Jul 2016 04:12:24 +0000

Just a quick note about how to enable telnet to your MacIvory III running Genera 8.3.

First, Edit Object Site NAME (obviously, use your NAME and not mine) in the Namespace Editor and add your network to the Secure Subnets. For example, for typical home networks you might add INTERNET 192.168.1.0 or your office might be INTERNET 10.0.0.0. Save the object.

If you are logged in, it usually turns remote access off. This can be odd because you can telnet in when you first boot, but not as soon as you start doing anything on the local console. To turn remote access back on even when you’re logged in, (neti:remote-login-on) is your command. (See Networks pages 13 and 21.)

XL1201 Moment of Truth

Sun, 24 Jul 2016 21:17:33 +0000

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. Blank screen (which means the monitor was at least getting a signal) but no boot, nothing. I hit the reset button a few times and powered it off and on a few times, and tried to reseat the card. Not a thing.

So, removed the Merlin II and took a very close look at it, comparing my before pictures to everything, to make sure every chip was in the right place and every pin was in its slot.

XL1201 Merlin II Chip Reseating

Sun, 24 Jul 2016 19:48:20 +0000

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 DIP chip on the Symbolics XL1201 Merlin II Main (CPU) board. Earlier I closely examined the solder side of the board and found a few minor discrepancies. This time I also encountered three discrepancies:

Bent pin on chip BB27 - unbent
Broken bypass cap next to chip GG7 - I clipped this one off entirely and will replace another day
One long bodge wire running along the entire top has come loose. This could get snagged on something and fall off.

Additionally, I removed and resocketed the Weitek Floating Point co-processor without doing any cleaning. It looked sparkling clean.

Detailed Inspection of XL1201 Merlin II Solder Side

Sat, 23 Jul 2016 19:18:35 +0000

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 flashlight. If I see anything suspect, I’ll take a picture with a (cheap) USB microscope.

I am doing a detailed inspection of the solder side of the Merlin II CPU card first.

Overview picture:

Discrepancies

There are only two that are concerning to me, but several others were found. The two of most concern are:

Enhanced X11 Keyboard

Wed, 20 Jul 2016 04:15:00 +0000

Well, after living with the default keyboard mapping for Genera under X-Windows, I decided to make an optimized one for an 87-key ANSI layout. The design goals were:

Utilize all the 16 top row keys efficiently, with most common functions in logical places
Utilize the 6-key quadrant for other common functions
Leave the arrow keys for cursor motion (because even though I have been using Emacs for at least 26 years I like my arrow keys)

Some of the important things that these led me to were:

Reloading Translations Files

Mon, 18 Jul 2016 00:47:27 +0000

Just a brief hint…

After you modify the file that has your translations (e.g., sys.translations), to make the new changes active, call (load-patches). Per Site Operations guide, page 514, section Translations Files.

Genera Xquartz Keyboard

Sun, 17 Jul 2016 19:42:01 +0000

It has taken some effort, but I finally created a reasonable (and close-to-default) keyboard layout and mapping for Genera for using a modern, 87-key “tenkeyless” keyboard under Xquartz. I became reasonably familiar (at a reading level) with Flavors and Genera’s X implementation while reverse engineering all this stuff. I also used the apropos function a lot, of course.

This layout stays very close to the default one provided by Genera while adding a few tweaks such as:

XL1201 Stability Update

Sat, 16 Jul 2016 15:47:51 +0000

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 booted the XL1201 and just let it sit in the Document Examiner.

Unfortunately, the computer decided to reboot itself after about 15-16 minutes. So, the power supply would seem not to be the problem.

I will have to disassemble the XL1201 and give it a thorough examination to see if there are any obvious physical defects. If none are found, I will try to remove, clean, and reseat all socketed chips, and see if that helps.

MacIvory III Transplant

Thu, 14 Jul 2016 03:57:38 +0000

Space is a premium in my little vintage computing paradise, so I had the bright idea of transplanting my MacIvory III from a desktop Quadra 650 to a tower Quadra 950 and clear some desktop space. David K. Schmidt said this was a simple matter, and he was entirely correct. I effectively put the Quadra 650 hard drive and the MacIvory card into the 950, rebooted, and blam, it “just worked.” (I actually put a clone of the Quadra 650 drive from 3 years ago in to test first.)

Todd MAX-354-1252 Power Supply for XL1201

Wed, 13 Jul 2016 23:28:33 +0000

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 you.

The power supply has six trim pots. Four are obviously labeled for adjusting the four output voltages:

5V at 50A
12V at 8A, 12A peak
-12V at 2A
-5.2V at 10A (for ECL circuits)

However, according to the expert engineers at Power Clinic “The two [remaining] trim pots in question are related to the front-end boost circuits. One is for operation frequency and the other is for boost fold. NEITHER should ever be adjusted.”

MacIvory III Setup and X11

Tue, 12 Jul 2016 04:57:57 +0000

As I haven’t had the time to continue to debug the XL1201 hardware problems, I turned back to the MacIvory III and an Intel i7 NUC I had.

First I set up Ubuntu 14.04 on the NUC with NFS and the “time” service, so I could use it as an always-on server for the Symbolics computers. This way I can put the full size SCSI computer away when I’m not actually imaging SCSI drives.

MacIvory and MouseKey 1.2

Sun, 10 Jul 2016 22:37:38 +0000

Well, I couldn’t find MouseKey 1.0 or 1.1.1 software anywhere on the Internet. Logitech has 2.0 on their web site, and I found 1.1 elsewhere.

However, the 1.1 software can’t see my mouse and the 2.0 software crashes.

So, I decided to buy NIB ADB Logitech MouseMan from eBay if I could find one, and lo-and-behold, this one has MouseKey 1.2 software in it.

Let’s see if MacIvory Genera 8.3 on Mac OS 8 can see my three button mouse…!

More XL1201 Crashes

Thu, 07 Jul 2016 03:56:51 +0000

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 going on somewhere.

Before the first crash, I put the Fluke 289 on 1-second measurement mode of the 5V rail. It was steady the whole time, even after the first crash at 20 minutes.

I then took a few hours break.

Later, I removed both Merlin II and Merlin I/O cards, put contact cleaner on all the socketed chips, and pushed down on them.

XL1201 Instability Next Steps

Wed, 06 Jul 2016 02:44:36 +0000

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 Reti would like to see backtraces to see if it’s a software problem. I will definitely get these for him; awesome to have a Symbolics expert offering to help - thank you.
I’ll put the Fluke 289 data logger on the 5V power supply rail and see if the voltage has any spikes or “events” when the computer reboots or acts strangely. If not, I’ll try the other three rails too (12V, -12V, -5.2V).
There are a number of tantalum bypass capacitors on the RAM, Merlin II and I/O boards. If any are going bad, they could short, heat up, “heal” and then work again for a little while.
- Test the tantalum caps for resistance (briefly, as the resistance will change as they charge) - anything under 6 ohms might be bad. This will be very difficult to do with the backplane caps, though; I may have to learn to disassemble the XL1201 chassis.
- After the problem happens, quickly power down and remove the boards to see if any components appear overly hot on the FLIR one IR camera.
Remove the cards again and push on all the socketed chips to make sure they’re all seated properly. Possibly apply contact cleaner to the socketed chips. Maybe the whole board - they seem dirty. Not sure if this “whole board” is safe or not.
Remove the cards and all socketed chips, clean the chip and socket, and reseat them. This would take a long time as there are a ton of chips and I haven’t pulled chips in literally decades. I would need to get a chip pulling tool and be super careful as this stuff is, as far as I’m concerned, irreplaceable.

Unfortunately, I don’t have a way to run the Merlin II without it being installed in the XL1201 chassis so I can’t test the caps directly or watch the heat signatures directly without doing a massive disassembly and hack job on the computer chassis, backplane, power supply, etc.

Power Supply, Memory, Crashes

Tue, 05 Jul 2016 04:03:54 +0000

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 voltages, install new RAM, and have a lot of problems and crashes.

XL1201 Power Supply Voltages

I tested the voltages of the XL1201 power supply with a Fluke 269 multimeter and a Rigol DS1000E, while the system was on and sitting at the FEP command prompt.

Multiple Crashes

Mon, 04 Jul 2016 17:34:46 +0000

I have been having a hell of a time today with the XL1201. It keeps crashing to the FEP from Genera. Very frustrating. You can Continue but it will crash again very soon afterwards.

Does anyone have any ideas, please?

Lisp stopped itself
Error trap 1001032504 not in emulator mode at #<DTP-EVEN-PC 37001102553> referencing #<DTP-PHYSICAL-ADDRESS 00001310200>.
(Use :Debug and c-M to record more information for a bug report.)
FEP Command: Debug (Keywords)
Error trap 1001032504 not in emulator mode at #<DTP-EVEN-PC 37001102553> referencing #<DTP-PHYSICAL-ADDRESS 00001310200>.
SI:AUX-HALT (PC = 40)
 --Defaulted args:--
 Arg 0 (SYS:FEP-COMMAND-STRING): NIL
→

FEP on Serial

Mon, 04 Jul 2016 17:26:41 +0000

Getting the FEP display on the serial port isn’t hard - as long as you want to use the serial port built onto the console. So far I haven’t seen a way to tell the FEP to use the serial port built onto the I/O Board.

FEP Command: Show Configuration
XL1200 4.0 Processor; Serial number SN-582; Reveision level: 1.0
I/O Board 0; Revision level: 5.0
2048k words physical memory at 00000000000
2048k words physical memory at 00010000000
Black and white Moniterm console 0

To get the FEP to talk to the serial port on the console simply connect a normal DB25 serial cable to the back of the console and to your serial port (or USB-to-serial in my case).

Symbolics Filesystems (Updated)

Wed, 29 Jun 2016 15:17:00 +0000

Update 1: Added FEP Kernel image.

ams asked me for a few clean filesystems so he can analyze how they work. Happy to oblige.

They’re here.

Configuration:

Device used: SCSI2SD v5
Created using Genera 8.3 clean world on XL1201
“Disk” initialized to all ASCII character ‘D’ bytes
80,000 blocks of 1,280 bytes allocated

The disk was dumped after each of these three steps:

Created Initial FEP Filesystem: fepfs-empty.dd.xz
Initialize LMFS on there: fepfs-lmfs.dd.xz
Create one text file, one directory, one text file in that directory, in each of the FEPfs then the LMFS: fepfs-lmfs-files.dd.xz
After running Copy Flod Files :Create Hello File Yes :Disk Unit 10 :From Directory FEP7:>: fepfs-lmfs-kernel.dd.xz

A transcript of the Lisp session is provided, using dribble, in make-fs-2.text. (Genera uses four letter file types, I saw no reason to change this here.) There’s also a README.txt that says much the same thing here.

Genera 8.3 Setup, Part 2

Tue, 28 Jun 2016 04:07:18 +0000

Good evening with the XL1201 tonight. TL;DR:

Got NFS working on Genera, mostly
- Need to fix UIDs
- Showed editing a file on NFS server
Showed the SELECT-P peeking stuff
Saved file listings for downloading
Fine lines on the console

Continuing on from Part 1…

NFS Server, part 2

Let’s export /genera for use in all our Genera servers, and make a UID/GID especially for that. I’ll also export the root read-only directory just in case I want to access any of my other files on this server.

Setting Up Genera 8.3, Part 1

Mon, 27 Jun 2016 04:48:00 +0000

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 and these patches:

Genera 8.3 y2k patches
Copy world patch
Fepfs patch

This hard drive was sold by David K. Schmidt and has had most things set up already, so we’re not actually doing a full installation from CD-ROM.

Let me preface this by saying that I have read a lot of the documents on Bitsavers but have no actual experience with Genera and haven’t had almost any guidance on what I’m attempting to try. My goal here is two-fold:

XL1201 Power Consumption

Sun, 26 Jun 2016 21:32:29 +0000

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 sitting idle it takes the same amount as calculating (fib 36), so apparently the CPU is running at a constant speed at all times.

When the console goes into sleep mode (after 20 minutes by default), power usage doesn’t appreciably drop.

Console sleep mode: 105W

With the XL1201 running a 15,000 RPM Seagate Cheetah X15 drive (ST318451LW), it doesn’t really take all that much more power.

Console Internals

Sat, 25 Jun 2016 18:09:57 +0000

This is a Symbolics Model PE36-PCONS, Part No 365404 Rev C console. My serial number is 21811. (“There are many like it, but this one is mine.”) An album of detailed internal photographs is available including full size versions of all the below images.

The console seems to be in good shape, with all electrolytic capacitors intact (not bulging or leaking). I should probably test the power supply outputs as there are trimmers for the voltages to adjust them.

3-button Mouse on MacIvory Fail

Sat, 25 Jun 2016 06:49:33 +0000

TL;DR: Still no luck using 3-button mouse on MacIvory. Need to find MouseKey 1.0 or 1.1 software.

My MacIvory III in a Quadra 650 running Mac OS 8 has a Logitech Mouseman (Model M-AH32), which is a three button mouse from Logitech. However, I never got that three button mouse working with Genera. I did just manage to get my hands on the MouseKey 2.0 software, though.

There are directions in the MacIvory User’s Guide section Configuring the Logitech MouseMan for Use with a MacIvory. I recall, however, reading things on the Internet saying that only certain versions of MouseKey will work, and I think those versions are 1.0 and 1.1 but not 1.1.1. (Thanks Google) I don’t recall reading anything about 2.0.