5 Jun
2005
5 Jun
'05
1:36 p.m.
From: "Randy McLaughlin" <cctalk at randy482.com>
Sent: Sunday, June 05, 2005 3:06 PM
From: "Richard A. Cini" <rcini at
optonline.net>
Sent: Sunday, June 05, 2005 2:46 PM
I just checked and mine are TB-2's with no transistors (four IC's instead).
I just use them as straight extenders with easy to access bus pins & power
separation. I have an HP logic probe that I like.
You might post on comp.os.cpm to see if anyone else has any TB-1's.
Randy
www.s100-manuals.com
All:
Part of the goodies that came with my IMSAI was a buss extender
board which has a logic probe on it, which I definitely use for
troubleshooting this stuck bit problem. One of the transistors on the
board
has a lead that's broken at the case.
The designation on the transistor is "F444". There's a second
transistor marked "F137" which also seems to have shakey leads. The
board
is manufactured by Mullen Computer Boards, model TB-1.
Can anyone cross these numbers to a current replacement? Googling
has come up with a possibility for the F444 but nothing for the F137.
Thanks.
Rich
Rich Cini
Collector of classic computers
Build Master for the Altair32 Emulation Project
Web site: http://highgate.comm.sfu.ca/~rcini/classiccmp/
/************************************************************/
I have a couple, I'll see if they use different transistors. It's a
simple probe and just saturates the transistors. I would guess that they
can be replaced with any general purpose switching transistors as long as
you match up PNP or NPN (2n2222 & 2n2907 ar my favorites).
If either of mine use different transistors I'll follow up.
I like the fact that the power lines can be isolated so it's easy to test
for voltage/amperage etc.
Randy
www.s100-manuals.com