Vintage Computer Festival GB, Snibston July 2013


I travelled up to the VCF-GB today at the Silicon Dreams event at Snibston Discovery Museum and took the opportunity to capture a few pictures.  It was pretty quiet being a weekday but I suspect it will be somewhat busier over the weekend.

I arrived pretty early and a number of exhibitors were still setting up.  AmigaKit, Amiga North Thames and A-EON were not present when I was there although I did get to see Morph OS running on a Mac Mini G4, demonstrated by a very helpful and enthusiastic Ravi Abbott.  I happen to have a Mac Mini G4 and will have a play with Morph OS later.

The BBC classroom was all set up and running, a most peculiar experience to see such a set up again.  Had my previous Retrochallenge not revolved around programming the BBC I probably would have taken the opportunity to have a play.

In various rooms around the museum there were rows and rows of computers and consoles set up ready to be played with and I took full advantage.  I felt my age when I witnessed a young lad trying to insert a 3.5″ floppy disk the wrong way round, seemingly completely unfamiliar with the technology.

I spoke at length to Dylan Smith of Spectranet fame who has developed the ZX Spectrum ethernet adapter utilising the WIZnet 5100 chip.  I not only admired the finished product but Dylan’s extraordinary soldering skills on the prototypes.  I also saw a working Harlequin board which was very cool.

I missed the IBM SYSTEM/360 Recreation which was pretty disappointing, not sure if they simply hadn’t set it up but I was really looking forward to that.  I would also liked to have seen more equipment from the 60’s and 70’s.

Here are some pictures and video, as you can see it was very quiet on Friday morning so little opportunity to capture visitors interacting with the exhibits.  If possible I may travel back up on Sunday to see if some of the missing exhibits have appeared.

PX8’s, Batteries & Retrochallenge 2011

Lately I’ve been experimenting with new batteries for my Epson PX-8’s (I have three PX-8’s now, it’s a worry I know.)  Of the three’s original batteries, one still holds a reasonable charge, the other two however require the AC adapters to be permanently connected.  This is not a huge issue but with high capacity NiMh batteries pretty cheap these days I decided to look into replacing the original NiCad’s.

The original NiCad’s are 4.8 V 1100 mAh packs, ideally I wanted replacements that were of equal or greater capacity.  Having hunted around and looked at a myriad of options it became clear the most limiting factor was the size of the battery compartment on the PX-8.  Initially I was tempted by a 4 pack of 1.2 V AA cells at 2700 mAh, however there was no way of squeezing these into the compartment even with a homemade pack.  I also looked at new NiCad’s but really wanted to go with NiMh.

In the end I tried two options, a ready made four pack of Sanyo Eneloop AAA cells at 800 mAh and some loose Duracell AAA’s at 1200 mAh secured in a simple 4 cell battery holder.  Both options are working well and lasting for what seems like forever.

I’m no expert on battery charging so don’t fully understand what the consequences will be of using the supplied Epson adapter and the PX-8’s charging circuit on the modern NiMh’s.  From what I do understand the PX-8 will charge for 8 hours and then drop into trickle charge with its standard NiCad.  If you disconnect the AC adapter and plug it in again the charge cycle will start again possibly leading to overcharging.  The AC adapter is an unregulated 6 V 600 mAh model. (Epson HOOAAU-A)

As far as I can tell, the NiMh’s are taking somewhere in the region of 2 hours to fully charge which seems to me to be what’s considered fast charging.

With July rapidly approaching my thoughts are turning this year’s Retrochallenge.  I have a number of possible avenues to explore.  Continuing with the battery theme I really would like to try and revive my PF-10’s.  I’m pretty sure the problem lies with dead sub batteries inside the units.  The main batteries are easy to swap out, however the sub batteries are soldered to the logic boards and it’s been a long time since I’ve been near a soldering iron.

I also have a Commodore 128D which I’d like to get fully acquainted with including using it with CP/M, in fact it would be nice to try and get it talking to a PX-8.  On that theme I’ve been experimenting with the PX-8 RS232 ports and quite fancy writing some sort of two player game with communication via this route.  Decisions to be made.

More Amiga Adventures

I’ve been spending a fair amount of time messing around with the Amiga 1200 that I recovered from the loft a few weeks ago.  It has been a little frustrating, I’d forgotten a lot about the Amiga and its idiosyncrasies and progress has been slow for several reasons that I’ll get in to below.

One of the main challenges I’ve found with retrocomputing is transferring files to and from your retro systems.  With the Amiga 1200 this isn’t really an issue due to its PCMCIA slot which will happily read and write to standard compact flash cards with the appropriate adapter.  A PCMCIA to CF adapter was therefore my first purchase (I later discovered I already had one grrrr.)

My next purchases were an IDE to CF adapter and some Kickstart 3.1 roms.  Installing the latter was pretty easy although it’s important to note the manner in which the original chips are installed as there are more sockets than there are pins on the chips.

I then pulled out the original Seagate IDE hard disk, plugged in the IDE to CF adapter and added a SanDisk Extreme III 4GB CF card.  I booted the system with my Workbench 3.1 floppy and set up the newly installed CF card.

I divided the card into a 200MB partition for Workbench and the rest as one large partition for games and data.  After formatting the partitions (some considerable time) I made a fresh install of Workbench 3.1 and booted the system from the new CF drive. This whole process was a little tortuous as the Amiga kept crashing at various stages.  At first I assumed the CF card was incompatible but I soon realised the 128MB SIM I’d installed was causing the problems.  I swapped it out for a 4MB stick and the machine become much more stable.

The next challenge was installing AmigaOS 3.9 which is supplied on CD and at the time I didn’t have a compatible drive for the Amiga.  Using a Mac I copied the contents of the CD onto a compact flash card in a drawer name AmigaOS3.9 and inserted it into the Amiga.  I then fired up shell and entered the following command – ASSIGN AmigaOS3.9: cf0:AmigaOS3.9 and was then able to run the installer with the CF card mimicking the CD.  However I ran into a number of problems with the installation and have since learnt that using a non-Amiga system to copy files or open archives destined for the Amiga can mess up the file permissions when you then try to use those files.  After much fiddling I finally got a semi working installation of Amiga OS3.9.

I seem to have stopped using my Amiga just at the point that CD rom drives became quite widely used with the system, I personally never had one but wanted to add one now so I could install the OS properly.  I ordered a buffered IDE interface and dug out an old Plextor external USB drive.

I opened up the back of the drive and disconnected the USB interface from the IDE connector on the drive and ran an IDE cable out of the box and into the Amiga.  I had to make some changes to the Tooltypes of the CD driver that had been installed by OS3.9 to get it working:-



I now had a working CD ROM drive and was able to successfully install OS3.9 without problems and also install the Boing Bag 2 update.  My next ambitions are to replace the external drive with an internal one, I already have a slim drive from an old Cubit box, whether I have the courage to cut a slot out of my 1200’s case is another matter, and Internet access.  For now some Frontier Elite II.