Socket to me

Fired up my new temperature controlled soldering iron and carefully desoldered the z80 in my 'mod' Speccy today in preparation for it to be socketed. It wasn't too traumatic but I did sweat bucketloads while I was working away, it is the first major desoldering job I've ever tackled after all.

 


The socket I've ordered should arrive any day now and hopefully I haven't ruined the original z80 although I have a replacement one to hand just in case, then I need to start thinking about replacing the ROM with an EEPROM/EPROM - once that's all working correctly then I can order my IDE interface... 

Spot of Bad Luck

The proto board I ordered from China (no-one in the UK sells them big enough for some reason) arrived snapped in two - it's the first time I've ever had a problem with anything from the far east.

I'm f**ked off but what can you do, I think I might give in and get a new keyboard membrane after all...

EDIT: The seller concerned not only responded to my email (to my complete astonishment) but after asking for a photo of the broken board is sending a replacement :). 

Regulation Issue

Got round to replacing the regulator in my project Speccy today with a RECOM R-785.0 DC-DC Converter. I couldn't get any pics of the actual replacement in progress owing to me not having 3rd or 4th arms, but it was straightforward and mercifully free from problems.

New DC-DC Converter in place.

If anything was going to go wrong then I have a few 7805's in my spares collection, so I took a pair of snips and cropped the leads of the old regulator, having first unbolted the heatsink from the mainboard. After binning the legless 7805, I warmed the joints holding it's remains one by one with my soldering iron and pulled the legs out with a pair of pliers, then cleared the holes with the solder sucker ready for the new component. 3 solder joints later the deed was done and I wiped the sweat from my brow, grabbed my PSU and gritted my teeth - Success!

Still no keyboard though... :)

I also performed this mod that I found on Sami Vehmaa's old site, it's meant to improve video quality by fixing some ghosting issues - on my (4A) Speccy it did nothing discernable. Perhaps I might perform the other video fix on his site at a later date and see if there are any notable gains from that.

Up to speed

I'm just really rehashing/transferring the Speccy stuff on my electronics blog for something for people to read until I get up to speed and have the chance to post something interesting, in the meantime here's a picture of a Speccy.

Keyboard Kapers

I want to keep one of my Speccys boxed and as original as possible, the other one however has no PSU, box etc. and was bought without any guarantee of working, so it's fair game for a project :). I have already ordered a large piece of proto board  after being inspired by seeing a rubber keyboard Speccy with it's keyboard membrane replaced with tactile key switches, so I think it's worth a go for the £10 it 'should' cost me.

Protoboard - £3.10:

And a 100 pack of these is about £5:

I want to preserve any original parts, so we will have to see how it goes so far as the overall 'feel' of the keyboard when typing. I'd like to be able to return it original condition if needs-be, so carving up the case lid or any of the key caps/plungers is not an option.

One idea I had was to add return springs (if I can source some) to the underside of the plungers to give the keyboard a bit more tactile feedback than just the bare switches but I need to measure the distances involved more carefully first, although the biggest headache I face is placing the switches in correct alignment with each individual key's plunger.

Spec, Tech, Pain in the Neck

After many Spectrum-less years I've just found myself to be the proud owner of 2x Speccys, both 48k Plus models (no rubber keys for me) one boxed and apparently in good working order apart from the keyboard and the other untested.

When they arrived, I quickly realised that I had 2x half working Spectrums, one with a working keyboard and a horrendous video fault, and one with a dodgy keyboard that seemed to work ok. That is, until the one with the dodgy keyboard got warm after a while of being switched on - then I had 2x Spectrums with horrendous video faults...