I bought this A310 (base unit only) from ebay in late May 2015. I knew little about the state of this particular machine and the ebay listing stated "Once plugged in and powered on the green light shows at the front - no further testing done - please bear this in mind when purchasing.".
photo wakeuk2015 (ebay seller)
From the ebay listing photo's I could at least discern that the machine had a backplane due to the presence of the AKA16 MIDI card but beyond that, there were no indications of what condition the machine was in.
photo wakeuk2015 (ebay seller)
When the machine arrived, I was pleased to discover that it was in what appeared to be its original factory condition although it was in need of a clean and had some minor hardware issues that had to be addressed. The machine was in such an original state, it still contained the original MEMC chip (named Anna) and the accompanying PAL chip.
The MEMC chip was revised and most Archimedes owners replaced it with the MEMC1a chip which, along with the PAL delivered an approximate 10% performance increase in memory access. The MEMC1a chip provided fixes to the MEMC chip which allowed ARM3 upgrades, support for Acorn SCSI cards and FPU podules (only in A400 series machines) to name just a few of the benefits of the upgrade.
I've documented the repairs in the Repair and Change history below.
This particular A310 has just a few expansions installed which are:
Although the motherboard was getting power when the machine arrived, it was not booting correctly as I suspected may be the case from the original ebay listing. The cooling fan was also not spinning which was indicative of a power issue with the machine.
Using a multimeter, I determined that the 12V line was only delivering 1.4V. This is indicative of a component shorting to ground which is a common fault. In the Archimedes A310, Acorn specified three 100uF Tantalum capacitors rated at 16V as decoupling capacitors for the power supply on the motherboard which can be seen in the photo below.
Arguably, the voltage rating for these capacitors is under specified and, as a general rule of thumb the voltage rating should be 2 or 3 times higher than the working voltage in use. Whilst the 16V rated caps are fine on the 5V lines, it's is not quite enough for the 12V line so a 25V or higher rated tantalum capacitor would be a better option.
The capacitor that de-couples the 12V line is designated as C37 on the PCB. Regardless of the rating, a quick way of working out whether the C37 is at fault or not is to simply disconnect one leg of the capacitor from the motherboard. If the machine begins to respond correctly then the capacitor is at fault and needs replacing. Doing so on this Archimedes caused the machine to boot into life.
The JASSP project run by Jon Abbott is an attempt to acquire the rights to all of the Acorn Archimedes games back catalogue and archive them for the future.
Archiving the games is just half of the battle. Jon has written ADFFS which allows those archived images to be loaded and played on any ARM based machine running RISC OS which involves patching these games to run on later hardware using a JIT/VM style environment within ADFFS to allow the games to be patched to run safely on the latest hardware.