Spectrum Computing

replaced d13 with a new one - no change tested the d13 when i took it out and it appears to be ok loaded up hyper active for the music and its playing ok but volume is very low I dont know folks but im real happy with the little machine and i rekon its good enough i remember from back then that the ...

Thanks for that lads - Ill swap out the other diode so Whats the story with these new membranes - I take it they are OK to open the machine and put it back together a few times and the membranes wont start cracking As I was fixing the machine a few weeks ago the original membrane kept cracking with ...

Hello again folks. Fixed my 48K , issue 4a bout 2 weeks ago and really having a blast going through the database of software. now im messing with sound demos But i still have 1 nagging problem - i can barely hear the speaker / sound its so quite I have to put my ear to the machine to hear the key cl...

Just to report back on the outcome - Got the little machine running 100% - IC 19 replaced ( thanks Mark ) , new switching 5 volt regulator , caps , membrane , feet retrolium does a mighty fine job - hats off to that man Really having fun loading up the memories from 40 years ago - amazed at how addi...

Hello again Mark, and again thank you for sharing your knowledge. thats was the kind of answer I was hoping NOT to get !!!! - cause it makes sense and seem right - The monitor looks like it does not take a composite signal. Especially with the other 5 pin din connection saying RGB input. Just flippe...

strangely , if i leave the ground in 17 and take the comp signal from pin 20 and put it in either the red , green or blue i see the spectrum screen , in red , green or blue ........ so there is a signal there but no composite display from pin 20 the composite mod i did on the spectrum was using the ...

Hello again good people. Trying to hook my 48k issue 4 to my color monitor Color monitor has a scart input , some kind of 5 pin din input for r,g,b, and a single phono input for audio. I have read that pin 20 and pin 17 on the scart connector are the composite input and composite in ground. So as a ...

Just want to say a big thank you for all the help I got from you all with this 48k Spectrum. Thanks to Mark I have the full 48K of ram. I have fully recapped the board. Replaced the 7805 with a switching regulator New membrane for the keyboard Found the fault with the sound - Replaced TR7 but that d...

Got it sorted people.

The smallest flake of solder I have ever seen from one of the holes to a trace

New cap is in place and machine working again

4 or 5 more to go

Hi Folks. Got my box of goddies from retolium and recapping my 48K issue 4a My first spectrum recap. All going good until I got to this cap ( yellow box in picture , just under the 2 new caps up by the power jack ) The cap i removed was a 1uf 50 volt - When I removed it , on the board it says d18 ( ...

I think I know what your saying - if a chip that is responsible for 1 bit alone , in an 8 bit sequence / bus , is stuck at 1 / high all the time , due to some failure , then it can be pinpointed because of its bit location within the 8 bit bus , tested on the actual board itself with a write / read ...

I got sorted Mark - As the lads told me above , you dont need a paypal a/c , just put in an email address and you can pay with credit card - Lots of goddies on the way , caps , diodes , transistors , switching volt regulator , 4164's , even rubber feet ....... spectrum gonna get a new lease of life ...

old age is getting to me !!!

yep - just put in an email and sure enough you can pay with a card , no paypal account needed

order in

good to know

Thanks again people.

Ok Dfzx -

Ill try that - I was looking for a button "pay as guest" to click on

would be so much easier than buying everything seperately

Thanks folks

Thanks for that edtoo

Had a look but they only have some of the stuff - its only UK companies fit the bill , UK is where the home computer revolution began and thats where the support is

ill keep looking - must be a company in UK that have all the parts that take credit card

Hi Folks. Just got my first spectrum working here in Ireland thanks to the great help from great people on this forum. My 48k needs a complete overhaul - caps , power , membrane etc etc , even the screws are missing. Just spent 20 min on Retroleum.co.uk , 16 items in my basket , went to pay and they...

Mark - you sir are a steely eye spectrum man SUCCESS https://i.postimg.cc/2VBfB5yV/IMG-5317.jpg Had to try it https://i.postimg.cc/ftg6V4hc/IMG-5318.jpg https://i.postimg.cc/Q9VzG6WH/IMG-5319.jpg Well done man - 2 little basic programs and you could tell me what ram chip was not happy - I would neve...

Again , Thank you Mark - you are a wealth of knowledge i got the 4164 out of the commodore no problem - ill fix it up with a socket so i can drop one in there when i get some strangely the speaker makes no sound when i connect the meter - still reads 39 ohm , the diaphram looks good , moves nicely -...

all good to know Mark. I will be replacing every cap in the machine took the speaker out , getting 39 ohms across the terminals , from reading , thats good quick test on D9 seems good leaving TR7 guy i got it from said a mod was carried out to to kill the sound from speaker - I cant see it - C61 is ...

Ill have to order them up was just hoping id have one here Mark cant buy anything in ebay anymore - im in south east ireland - you buy 1 chip on ebay and you have 20 euro shipping - what a joke - the joke that is known as the EU have made a mockery of so much - 20 quid to ship 1 x 16 pin chip , i ki...

looking at ram in old atari st 1040 - tms 4256 - 15nl

nope its not looking good so far - looking at macintosh ram simms - i read that some apple ii e's had that chip - going through what i have

will have to take a trip into the attic

just counted the pins - god im stupid !!

its a 128K +2 B Mark

Opened it up and had a look - what I think are 4 ram chips , socketed

one of these work ?

well i went ahead and removed IC19 was allot more difficult that expected - couldnt get all solder out from both sides so had to use air gun for final removal dont think i damaged any pads or traces - will have to clean it up for a better look. Now I have to hunt down a suitable replacement chip I h...

I took readings those readings from ic19 and z80 , at 2kΩ and 200Ω - got zero in both reads had a look with magni glass at ic19 , pins , traces - could not see anything obvious = all looks good powered on machine for 10 min , took temp readings of chips - ic19 was 2 degrees warmer than surrounding c...