emulatorII-list

Here is the one I have installed. It's a Zenith ZPS 150a. Not quite as
compact as that Meanwell but it does the trick.

http://www.dblondin.com/Images/emulator_ps.jpg

Darren

> An update, rather later than planned.
>
> Over the last month or so I have been trying (and failing) to get the EII
> to boot. After connecting it to my HxC I was able to run the RAM
> diagnostic disk image and found a couple of supposedly dead RAM chips.
> Swapping these solved that problem, but it still wouldn't boot. A couple
> of days ago, my rebuilt PSU decided to start making a very loud wine,
> which I suspect is caused by the feedback circuit oscillating, so despite
> the fact that I have replaced all of the caps, power resistors and
> transistors, there is still a fault somewhere.
>
> All PSU rails check OK with a multimeter, but I don't have a scope (one of
> those things that I keep meaning to buy) to check for ripple. If the
> feedback circuit is indeed oscillating, I imagine it would cause a fair
> bit of this!
>
> I think it is time to give up on the PSU and look for a modern
> replacement. There has been a discussion on the EIII forum about this,
> including a link to this page: http://www.synther.org/emulator2.html. The
> PSU looks like a Meanwell T-60C, providing 5, 15 and -15 volts at 5, 2 and
> 0.5 amps respectively. Has anyone used one of these?
>
> In the mean time, I decided to have a play with an ATX PSU – and it boots!
> I haven't done any further testing with this as the keyboard is currently
> dismantled, but it seems to prove my bad PSU theory.
>
> Kevin
>
>
> --- In emulatorII-list@yahoogroups.com, "kgslug2"  wrote:
>>
>> Thanks Nigel,
>>
>> I'll have another play with the memory chips tomorrow. I have an HXC in
>> my EPS16, so I'll borrow that and make up a cable to use it with the EII
>> and give the memory test disk a try.
>>
>> Kevin
>>
>> --- In emulatorII-list@yahoogroups.com, Nigel Cruickshank  wrote:
>> >
>> > Kevin,
>> >
>> > The first row of 8 memory chips on the main board (at the right side
>> closest to the keyboard) are the ones that load the boot sequence.
>> Swap these 8 out for another row – the third or forth row – and see if
>> this makes a difference.
>> >
>> > My EII was hanging on boot and after swapping a row out I had a fully
>> operational EII.  After that I ran the memory test disk (from my HXC)
>> and located the faulty chips and replaced them.  It was a slow process
>> but eventually I got them all and now the memory test passes without
>> fault.
>> >
>> > Let me know if this helps,
>> > Nigel
>> >
>> >
>> > On 12/12/2012, at 9:44 AM, kgslug2 wrote:
>> >
>> > > Having fixed the PSU and the short on the output board, I was rather
>> hoping to have a working EII. Unfortunately this was a somewhat
>> optimistic assumption!
>> > >
>> > > On power up, the LCD reads "**Emulator 2** Boot in progress",
>> followed a few second later by "Insert Diskette". Inserting a disk
>> gives "Software Rev 3.1", followed by "This will take a while". The
>> disk drive clicks for about 30 seconds, but booting never finishes.
>> It either freezes at "This will take a while" or seemingly reboots
>> and reverts to "**Emulator 2** Boot in progress", repeating the
>> whole process until I switch it off.
>> > >
>> > > I have about 50 disks and have tried maybe 20. I have also tried
>> both drives, with the same results. Suspecting it could be a RAM
>> problem, I swapped the ICs from the memory upgrade board to the
>> digital board, again with no change in the outcome. Any ideas?
>> > >
>> > > Kevin
>> > >
>> > >
>> >
>>
>
>
>
. The