Page 3 of 44

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Mon Apr 09, 2018 11:24 pm
by rubber_jonnie
Ouch, that CPU looks like a bit of an arse to solder. I guess since the pin dimensions fall inside a PLCC socket, that means a socket for the CPU is a no go?

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Mon Apr 09, 2018 11:26 pm
by exxos
rubber_jonnie wrote:
Mon Apr 09, 2018 11:24 pm
Ouch, that CPU looks like a bit of an arse to solder. I guess since the pin dimensions fall inside a PLCC socket, that means a socket for the CPU is a no go?
Not sure I follow... Whole idea of this booster is to avoid the PLCC socket for the CPU..

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Mon Apr 09, 2018 11:29 pm
by rubber_jonnie
exxos wrote:
Mon Apr 09, 2018 11:26 pm

Not sure I follow... Whole idea of this booster is to avoid the PLCC socket for the CPU..
Sorry, I'm being a bit dumb, we've probably talked about this, I'm just a bit tired and confused at the minute....

:dizzy:

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Mon Apr 09, 2018 11:33 pm
by exxos
rubber_jonnie wrote:
Mon Apr 09, 2018 11:29 pm
Sorry, I'm being a bit dumb, we've probably talked about this, I'm just a bit tired and confused at the minute....
Welcome to my world ;)

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Mon Apr 09, 2018 11:38 pm
by exxos
How it looks so far...

IMG_2404.JPG
IMG_2404.JPG (133.19 KiB) Viewed 1346 times

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Tue Apr 10, 2018 12:05 pm
by IngoQ
rubber_jonnie wrote:
Mon Apr 09, 2018 11:24 pm
Ouch, that CPU looks like a bit of an arse to solder. I guess since the pin dimensions fall inside a PLCC socket, that means a socket for the CPU is a no go?
I take it, you are talking about a socket on the booster board, not on the mainboard... IMHO the pads for soldering a PLCC SMT socket are identical to those for direct soldering, so putting a socket on it should be no problem. A socket is actually much easier to solder, since you can pop out the lower pane of the socket for easier access to the pads. Then you simply do drag soldering and everything is fine. I did so a couple of times with my STE that had a SMT CPU and no socket.

See my adventure here: viewtopic.php?f=18&t=358

Direct soldering is probably easiest when using an oven, I had mediocre results with a hot air station. But as long there is room around the the chip, you can reach the solder points with a fine tip and resolder, if necessary.

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Tue Apr 10, 2018 12:25 pm
by rubber_jonnie
Yes, I was talking about the booster board, and not the mainboard.

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Tue Apr 10, 2018 1:33 pm
by exxos
The booster has been on for a few hours now about to tick over to loop 60. So I think it is safe to say this is all stable. I seem to be mostly having socket problems the dual tos board :roll:

Will have a look and see if I can find some slightly higher speed oscillators to try next...

UPDATE:
some reason this booster really does not like a oscillator :( I cannot even get it stable with a 25MHz one. The original V design did obviously work with a separate oscillator as I had it working easily. As to why this board misbehaving I really do not know. Maybe it is down to the revision of motherboard or something.

The clock switching on the CPU looks perfectly fine. Some of the oscillators do seem to have a 1 V DC offset made things a little bit more complicated. Do a few more tests but as is misbehaving right from the start I think using a external oscillator is probably a bad idea :(.

UPDATE 2:
I removed the capacitors from the 8 MHz line and then machine booted up the 25 MHz oscillator. So then I tried a 35 MHz oscillator, but it mostly crashes just after the logo appears. It could be CPU simply maxed out, looking at the clock line, there seems to be a 1V offset when it switches to 35 MHz. I have removed the series resistors try and gain a little more voltage but seems to buffer simply cannot work at this speed :roll:

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Tue Apr 10, 2018 4:42 pm
by exxos
So I was just about to basically give up with a external oscillator, but I tried some other ideas and now I am running at 32.768MHz.

IMG_2407.JPG
IMG_2407.JPG (139.4 KiB) Viewed 1631 times
32768.jpg
32768.jpg (107.52 KiB) Viewed 1631 times

And this is the normal 32 MHz.. Please ignore the statistics for comparison as this image below is the previous version of GB6..

Though the only real interesting one I suppose is integer division..

Image


UPDATE:

Now 35MHz :)

35000.jpg
35000.jpg (102.14 KiB) Viewed 1629 times


UPDATE - 40MHz :twisted: :twisted:

40000.jpg
40000.jpg (106.95 KiB) Viewed 1625 times

Now I need a 42MHz osc :roll:

Re: STE V1.5 32MHz BOOSTER - STATUS

Posted: Tue Apr 10, 2018 5:55 pm
by tuxie
Did you use different Reference values ?
Never found an 42Mhz OSC :( my TT is working with 40Mhz but not with 48Mhz so when i can get something between 40 and 48 so i think i can archive this..