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2015-06-17

A/UX on real hardware

So, I've been playing about with Unices on some old 68k Apple hardware. NetBSD supports the hardware fairly well, but I found it was fussy about the various SCSI to IDE/CF-card adapters available. In the end, SCSI2SD seems to be the best overall, with MacOS, NetBSD and Linux all working fine with this. Definitely recommended for old kit.

I prepared an EMILE based bootable ISO of the latest m68k Linux release. This got to the installer on my Quadra 610, but failed to get that far on my LC III. I thought I'd try something else.. A/UX. And it worked! I had to use a real CD-ROM drive. For some reason, the CD-ROM emulation provided by SCSI2SD is enough to get Linux to boot, but not enough to get an HFS CD-ROM image to mount under MacOS. In the end I bought a CD-ROM drive off eBay, and added the suitable "System Enabler" to the A/UX install floppy. And it worked!



If I get an external case for this CD-ROM drive, or just buy a suitable external Apple SCSI CD-ROM drive, I could try to install A/UX on my LC III. The LC III is listed as unsupported, as A/UX needs an FPU - well, I added one to mine, so it's worth a shot. The LC 475 is supported, I'm not sure how different these are in terms of on-board devices.

2015-05-20

Things!

Things have been happening.

I finally got around to installing the Ultimate 1MB from Lotharek into my PAL Atari 65XE. It looks like this:


Yes, those broadcast antennae, one carrying the system clock, actually work. It's a neat system, which emulates multiple RAM expansion systems and multiple ROMs too. It's very easy to install, though you have to piece together the instructions yourself, as there have been multiple variants of this board. This is the latest, and is actually very easy, only requiring soldering four wires, and a couple of sockets. Most of the time was spent soldering and crimping some Dupont connectors for the headers. My board has rather obviously had some previous upgrades and repairs done to it.

I also bought two SIO2PC cables, one RS232C-based from eBay, the other USB based from Lotharek. I used these to log into a BBS using the ICET software on the Atari, logged into my ThinkPad X201 running Ubuntu MATE. The AspeQt software suite is very neat, allowing simulating Atari drives from disk images or file system folders, so you can cross-develop on a modern machine, test and debug under an emulator, but also very easily test on real hardware.


I also repaired, not one, but two Commodore Plus/4 computers! One was the only computer from my childhood to survive various purges at my Mum's house. It is the computer I used the least *as it was broken back then*. It had a faulty BASIC ROM. I had planned to put in an EEPROM, which I ordered, but decided to just get a replacement original ROM. I should replace the electrolytic caps in this. The PSU suffered damage in shipping. I re-soldered the big capacitor that had been rattling around. Luckily I checked the output voltage before plugging it into anything. It was spitting out about twice the voltage it should have been, so I cut the cord and threw the PSU out. I used the cord to make an adapter for a C64 PSU.

The other +4 was one I bought on eBay. I socketed all the chips on this, replaced all the electrolytic caps, and replaced the one faulty IC - a buffer, that I eventually tracked down.

I added some heatsinks to both +4s and they are running fine. I even loaded some games from tape, though I will mostly be using the sd2iec with these. If I can find time, I want to play the port of Magic Candle on these old machines. The video output is much, much better than my C64c (which I probably need to look at).

I also re-capped a Mac LC I, but it seems too late, as it is forlornly giving the chimes of death, indicating a RAM failure. I just picked up an LC II mainboard from eBay for 5GBP as a replacement. It will be re-capped. An LC III that was squealing with bad caps was repaired and now runs fine. I also re-capped a Quadra 610 that seemed to be running fine, but in fact had slight leakage from the caps.

I went through a couple of SCSI->SATA interfaces and didn't have any luck installing NetBSD until I tried the SCSI2SD interface. It works. If you're looking at 50 pin SCSI adapters for retro systems; look no further. The SCSI2SD interface seems to be the most compatible.

Last night I finally got around to trying out the revived m68k Debian, using the scsi2sd's abilities to emulate multiple disks, including a CDROM.

On my LC III, it booted:



Loaded the kernel:



Got the kernel running:



And then got stuck:


But at least I got to see Tux on real hardware.

This morning, whilst waiting for builds, I tried things out on my Quadra 610. After a false start due to dumb incorrect termination of my SCSI bus, things went more smoothly:



The Installer!


I don't have that many compiles to wait for, so I'll have to get back to this another time...




Other things I've been up to:
Bought two HBI-232 serial interfaces for my MSXes.
Bought 2 Z88s and bits for them. Lots of support for these cool machines now!
Bought an updated DIVIDE 2k14 for my Spectrums.
Bought a Spectrum 48+, and of course a new membrane for it.
Bought the SPECTRA interface for the Spectrums with ROM interface and ZXC4 flash ROM - excellent video quality
Bought the Interface 1bis for the Spectrums
Bought an SGI O2, and an SCA (SCSI)<->SATA adapter.
Bought an HP 380DL G5 server, upgraded the processors to X5470s, RAM to 32GB
Bought an HP Z800 workstation, upgraded the processors to X5670s, RAM to 64GB
Bought an Amstrad NC100 - will put ZPC on it
Bought a couple of Raspberry Pi B+ 2's (of course!) and some bits for them. Set up RetroPi on on SD card & USB stick combo "for my daughter" so that I don't have to keep swapping out an Atari/MSX/C64/Spectrum depending on which game she wants to play.

I'm sure there's some random hackery I've forgotten...

I've still got to add the VXBE video and stereo POKEY upgrades to my 65XE, and I'm tempted to paint the case. I'm also tempted to do a custom Spectrum case.

But, I'm done with purchases for now, and have plenty of ideas for retro projects. Well, maybe I'll buy a backup C64. Clearly I'm missing a Spectrum 128... And if anyone is selling a Sun 3/80, I'd be interested.

Edit: Oh yes, finally got around to fixing the video on my Toshiba HX-20 (MSX). It was a dodgy video RAM chip, as I suspected. I have captured some video output from the Toshiba, the Yamaha CX-11 and the Sony HB-1FXDJ to compare them. I made an RGB cable that works with both the Yamaha and the Sony, and the video quality is excellent.

I captured the "bad cap scream" from my Mac LC III. I'll upload that at some point.


2015-03-18

Sidestreets explored by looking at the "Retro" proof assistant LCF

An off-hand mention of "retro proof assistants" in a facebook comment had me look at LCF. It's been quite some time since I've read any CS theory outside of the more pragmatic side of PLT and FP, and even longer since I've read up on any logic or mathematical foundations. There's a bit on LCF in "Proof, Language, and Interaction". But now I've got some amazon orders to look forward to.

I wish I had been at this talk by Paulson:

http://events.inf.ed.ac.uk/Milner2012/slides/Paulson/LCF+-without-transitions.pdf

I remember coming across Skolem's paradox some time ago, and not really understanding it. I think I just had a quick look at the Wiki page and shrugged, getting on with something else (probably work).

Skolem's paradox:
http://en.wikipedia.org/wiki/Skolem%27s_paradox


The single slide on Skolem's "Paradox" in Paulson's talk above explains it in a nutshell. Nice.

UPDATE: The videos from the Milner Symposium are online:
http://events.inf.ed.ac.uk/Milner2012/videos.html