English Amiga Board

Go Back   English Amiga Board > Support > support.Hardware > Hardware pics

Thread Tools
Old 03 July 2009, 18:01   #1
. . Mouse . .
Charlie's Avatar
Join Date: Jun 2005
Location: Nowhere
Age: 51
Posts: 1,792
One for the Electronics Gurus... Please

D*mn, but my run of bad luck is continuing with a vengeance...
...ho, hum. Never mind.

Anyway, I'm trying to resurrect an old project. I have a fully made PCB that I'd like to 'reverse engineer'.


of the bits

From the bottom-up we have a beige two-pinned box that I believe is a metalised polythene capacitor - correct?
The only markings on it say: <inverted triangle> .1363
Not a familiar marking to me. What value does this work out as?

Next we have a 9-pinned blue 'thing' just North of the IC...
...what is it?
Markings say: CTS8522 770 91 2.7K
I assume it's a multi-legged 2.7K resistor - where to get some from?

Finally the IC, It's code says DM74LS245N. An Octal Bus Transceiver I believe...
...a real bugger to find - even DigiKey doesn't stock them. Any idea where to source these or a pin-compatible equivalent?

Many thanks.
Charlie is offline  
Old 03 July 2009, 18:47   #2
Ya' like it Retr0?
Zetr0's Avatar
Join Date: Jul 2005
Location: United Kingdom
Age: 45
Posts: 9,768
the 74ls254N is a common IC m8y.

http://www.futurlec.com/IC74LS00Series.shtml 23pence each

blue thing = 9 pin 2.7k resistor network.

http://www.futurlec.com/ResNetworks.shtml about 15pence each, closest they have is 2.2k

you can find the value of these using a multi-meter and tying off both ends

the block with "Delta.1363" looks like a high voltage polyester film capacitor, perhaps mylar?. Again you can use a multi-meter with a current to work its capacitance.


what circuit did you get this from?
Zetr0 is offline  
Old 03 July 2009, 19:42   #3
. . Mouse . .
Charlie's Avatar
Join Date: Jun 2005
Location: Nowhere
Age: 51
Posts: 1,792

Thanks Zetr0.

Doh! 74ls254N common, eh? Just goes to show how rubbish I am @ searching for IC's...

I'm 'collecting' hacks + upgrades for RiscOS computers - I've pretty well exhausted the ones for which plans exist, so now I'm going to try recreating plans for the boards I have or can get hold of.
This one is for turning the serial socket on an A3000 into a joyport.
The next will be for turning the parralel port into two joyports.
After that I'll try for a econet to SCSI card.
Maybe try one of the simpler ARM3 boards too (if I can find any ARM3's)

I've hit a bit of a speed bump with testing of hacks - I've got two A3000's: One with ARM3 & one with ARM2. I've just replaced the ARM2 in the second with a PLCC socket and bought another ARM3 board off fleaBaby to put in it. I put it in my newly ARM3-enabled A3000 for testing (fine with a socketed ARM2) - nothing...
...like a fool I tried it in place of the ARM3 in my main A3000 - nothing...
...now neither will work in their original state. I guess I now have two dead motherboards!
The new ARM3 board must have been a dud.
Charlie is offline  
Old 04 July 2009, 03:01   #4
. . Mouse . .
Charlie's Avatar
Join Date: Jun 2005
Location: Nowhere
Age: 51
Posts: 1,792
Serial Port JoyStick interface layout done in case any were wondering.

Hey! Quite neat considering it's hand drawn

I can't guarantee this will print 1:1 - Quick conversion to an allowed format could have messed things up.
Charlie is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
request old popular electronics january 1990 rampartsagain request.Other 5 03 June 2012 18:11
Os 3.9 gurus on a1200 8mb fast 030 _ThEcRoW support.Apps 14 16 March 2008 11:20
Getting a lot of gurus on A500! memothejanitor support.Apps 7 22 June 2007 21:30
My WinUAE HD GURUs at startup jjsmith22 support.WinUAE 7 09 April 2005 02:19
Scandoubler gurus needed. Desverger support.Hardware 7 05 August 2004 16:57

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT +2. The time now is 18:41.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Page generated in 0.09732 seconds with 14 queries