TRS80 mod 4 ver1 video/memory problems

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Sat May 31 13:11:00 2003

> > When you reseated socketed chips, did you also do the ones on the FDC
> > board? Have you checked -- carefully -- the ribbon cable between the CPU
> > and FDC boards? I've had a lot of problems with those cables in M3s and
> > M4s.
>
> Speaking of which, whats best to replace these with? Both my model 3 and
> model 4 suffer from bad cables.

I believe I've seen that tapewire in at least one catalogue. It was an
almost-standard part at one time.

However, what I did on my M3 (my M4's cables were OK) was totally
non-original. I desoldered the connectors from the CPU and FDC PCBs and
replaced them with SIL 20 pin headers. I then used a 40 way IDC cable
(like a PC IDE cable) to link them, just using one row of holes in each
connector (and making sure I picked the right row to have connections
:-)). Seems to work fine.

-tony
Received on Sat May 31 2003 - 13:11:00 BST