VT101 8085 CPU Fault

Diane Bruce db at db.net
Mon Jan 19 15:45:40 CST 2015

On Mon, Jan 19, 2015 at 04:39:30PM -0500, John Wilson wrote:
> On Mon, Jan 19, 2015 at 09:26:57PM -0000, Robert Jarratt wrote:
> >In my latest tests I found that the CPU does indeed seem to HALT,
> >according to S1 and S0 (both go low).
> What ever happened to in-circuit emulators?  I used an 8085A ICE in
> a microprocessors class at Boston U. in the 1980s and it was *magic*.
> I always wondered how they worked -- is it just an 8085A with a doctored
> clock, or some complete re-implementation of it, or what?  Physically
> it was a 40-pin DIP plug with a thick cable leading off to a mass of
> electronics.  It's just the kind of thing that would turn up on eBay,
> but only if you didn't need it.

His problem is he will have to unsolder the 8085 first. 
I'd suspect RAM since the ROM is (I assume) masked ROM.

> John Wilson
> D Bit

- db at FreeBSD.org db at db.net http://www.db.net/~db

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