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Messages - Witchy

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Hardware / Re: 12V coil (L1 on schematic)
« on: 2017.August.25. 19:58:09 »
I thought it was dead because it wasn't buzzing :)

There's a specialist wire company not far from me that will gauge the thickness of the existing wire and sell me a spool of new stuff, rewinding them is fairly straightforward so I'll do that next week.


Hardware / 12V coil (L1 on schematic)
« on: 2017.August.23. 01:00:59 »
Hi folks,

One of my EPs has a dead coil so I've done what I normally do with ZX Spectrum coils and unwound it to remake it with new magnet wire, only to discover these coils use a thinner wire than 0.3mm. Since I don't have any calipers to measure this wire I have to send it off to a wire company so before I do...Questions:

: has anyone successfully remade one and if so what size wire did you use?
: is there a modern equivalent
: can I rewire this one in the same way I do Spectrum ones with the same turn ratio and 0.3mm wire? I'm ashamedly crap at maths to work this out for myself :)

There's one post here from 2014 where Zozo suggests replacing the entire 12V circuit which is easily done I guess but I'd like to rewind this coil if I can.


Hardware / Re: EPNET 1.2
« on: 2017.July.24. 22:25:27 »
Fantastic effort there!

I have several EPs near Cambridge if you need beta testers :ds_icon_cheesygrin:

Maintenance / Re: 64K RAM board troubleshooting
« on: 2017.July.13. 22:05:14 »


Maintenance / Re: 64K RAM board troubleshooting
« on: 2017.July.11. 23:51:14 »
Sweet, another one fixed. 2 broken wires that didn't become obvious until I took the board out to buzz it with a DMM :ds_icon_cheesygrin:


Maintenance / Re: 64K RAM board troubleshooting
« on: 2017.July.07. 20:33:17 »
You can use the keyboard membrane without the top of case.

Hah! Why didn't I think of that :mrgreen:

Maintenance / Re: 64K RAM board troubleshooting
« on: 2017.July.06. 23:43:26 »
Evening all,

I've remade the joint from the LS244 to the 5V line on the 4164s but getting the RAM test to hold without a keyboard connected is difficult. What's the preferred method of supporting the keyboard while still being able to get a DMM in to test voltages?


Maintenance / Re: 64K RAM board troubleshooting
« on: 2017.June.26. 19:34:42 »
Hi Zozo,

Yes, I think the 5V wire for the 4164s is suspect since I resoldered it after removing/reseating the board and now there's various bits of RAM marked bad on power up so I'll reflow it again at some point :)


Maintenance / 64K RAM board troubleshooting
« on: 2017.June.24. 15:30:23 »
Hi folks,

After embarrassingly fixing my failing EXDOS problem earlier I now seem to have a dead 64K card in my hand-upgraded EP128. Zozo's RAM test in EXOS 2.3 detects 128K but fails it instantly which makes me think it's a 5V problem so I'll look at that later, but in the meanwhile is there a known fault with these boards? I've already reseated it.



Interface / Re: bridgeboard to EP contact
« on: 2017.June.24. 15:11:25 »
I remember doing that a lot last year, as well as cleaning the contacts with an eraser.


Zozo's RAM test at power up showed 64K bad so I started looking at the add-on 64K board and noticed the screws were missing from the motherboard. :oops:

EXDOS is fine now but I'm still 64K down.

That's a job for tomorrow...

Interface / bridgeboard to EP contact
« on: 2017.June.23. 23:51:55 »
Hi folks,

I can't believe it's a year since I was last here, pretty much. I've been dipping in and out every so often to check up on the progress of the SDcard adapter, it's looking pretty sweet now!

Anyway, it's exhibition time again so I've dug out my fixed-and-upgraded-last-year EP128 only to remember that its connection to the bridgeboard and therefore EXDOS just doesn't work despite cleaning and trying 3 different bridgeboards.

Has anyone come up with a 'oh wow THIS works!' moment in the last few months? :)



Hardware / Re: Your Enterprise configuration?
« on: 2016.September.01. 01:26:22 »
Hi Sinclair200, that's an excellent collection of machines and bits, I've never seen another Miracle Systems QL floppy or 512K Expandaram so it's nice to know others are out there.

A DiSCIPLE too, nice....

Hardware / Re: Your Enterprise configuration?
« on: 2016.August.06. 23:16:15 »
OK, RAM pullups added and I found a set of floppy drives ostensibly for the QL (since they have MEDIC written on the plug after the QL disk interface of the same name) but they work nicely for the EP and look the part!


Hardware / Re: Your Enterprise configuration?
« on: 2016.July.28. 23:07:50 »
Nice configuration!

Did you checked the ROM version before the upgrade?

Yep, it's 2.1 and now in my spares box. I'll see if I can chase down someone who's willing to sell me only a few of those resistor networks, most e*ay sellers want to sell 40 at a time!

Nice to have a steady working setup too, pity my floppy drive flaked out at the Recursion exhibition a few weeks ago but it didn't seem to matter, people were just interested in the machine itself. What utility can I use to put DTF images back onto real floppies?

Hardware / Re: Your Enterprise configuration?
« on: 2016.July.28. 21:50:17 »
Yay, my replacement keyboard membrane arrived from RWAP yesterday so I fitted it tonight. While the top was off I also burnt a 27C512 EPROM with Zozo's EXOS 2.3 and added the extra wire for A15. Tempted to get my dual Cumana floppy drive set sprayed black so it all matches :ds_icon_cheesygrin:



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