Date   : Thu, 26 Feb 2004 12:11:52 +0100
From   : "Eelco Huininga" <e.huininga@...>
Subject: Re: ID Acorn board

This is an Progessive Establishment Tester.

Excerpt from the Acorn BBC Service Manual:

---[ snip ]---
6.2 Test Equipment
The very minimum test equipment required in order to trace even the simpl
est fault is a digital multi-meter and an oscilloscope (or possibly a log
ic probe). It is difficult in a book such as this to do more than give a
few general guide-lines as to the sort of problems to look for, and a few
 techniques which might be used.
Acorn Computers Ltd supply two pieces of test equipment which are specifi
cally designed for the BBC Microcomputer which are known as the PET (Prog
essive Establishment Tester) and the FIT (Final Inspection Tester). Whils
t the service agent or dealer might be expected to have these pieces of e
quipment, the average user is unlikely to feel that it is worth purchasin
g them for the limited amount of fault-finding he or she would be likely
to do. The purpose of the PET, which is the more expensive of the two ite
ms, is to take an apparently lifeless computer and attempt to find out wh
ere the fault lies. The FIT on the other hand is somewhat simpler and its
 aim is not to isolate a known fault but to check whether an apparently w
orking computer is in fact working in  all respects. Both the PET and the
FIT are the subject of entirely separ
ate documents produced by Acorn Computers PLC.
Two other very useful pieces of "test equipment" are a can of freezer spr
ay and a hair-dryer! It is fairly common for faults in some of the ICs to
 be associated with temperature conditions. Therefore if you have reason
to suspect a particular component, it is sometimes helpful to "exercise"
the device by the use of these two items. This can sometimes show up a fa
ult quite clearly. However, this can be slightly misleading in cases wher
e the fault is caused by a timing problem on some device. This is because
 changing the temperature conditions of one device which may not itself b
e at fault, may, by changing the relative timing, bring the timing back i
nto a working condition. Therefore having discovered a device which appar
ently has a temperature fault, before  de-soldering it, it is well worth
temperature cycling the associated com
ponents.
---[ snip ]---

You can find the full Acorn BBC Service Manual at http://bbc.nvg.org/doc/
BBCBServiceManual.zip

Hope this helps


Cheers,
Eelco



>>> Savvidis Ioannis <I.Savvidis@...> 02/26 11:03  >>>
Hello everyone. 

 

Going through a couple of boxes that I collected from the local Acorn
dealership of yesteryear I noticed an Acorn P.E.T board. One red and one
black lead supply 5V to the board, which has 7 or 8 IDC connectors of
different sizes. Another smaller board attaches to one of the connectors
and
has at the other end, a 40-pin spring clip, apparently to attach to an IC.
The board has four (4!!!!!) 6522s. Does anyone know what exactly this boa
rd
is? I couldn't get any photos last night, but I'll try to do it tomorrow.
=2E.

 

Thanks.

 

 

Yannis