Hi Tony,
On 05/10/2015 16:55, "tony duell" wrote:
> And I would be surprised if you got nothing on the screen either. Odd bit
> rot would mean the wrong patterns for some characters. But still something.
The heater is working in the tube and now that I've got a proper DMM I'm
getting the correc
One chip getting hot does bother me.
Have you measured the voltage rails.
If the voltage is gone, it may be shorted.
Just swapping it out may not be a good idea unless
you know that it wasn't a failed regulator that
caused it to short out.
Some of the TO-3 type regulators depend on the
screws con
On Mon, Oct 5, 2015 at 2:52 PM, william degnan wrote:
> Look for inconsistencies in voltages and pulses to and from RAM.
Yep.
> You may need RAM at the lowest memory locations to boot.
Absolutely. The startup routines will be unhappy if zeropage is not there.
You can check for -5V as well, si
On 05/10/2015 19:52, "william degnan" wrote:
> Look for inconsistencies in voltages and pulses to and from RAM. You may
> need RAM at the lowest memory locations to boot. Hooking up the keyboard
> at least to eliminate a missing keyboard as a reason the system does not
> boot, and you can issue
> Is UD11 the only empty socket? If there's a chip
> in UD12 I'd remove it in case it's defective or
> has bent pins etc.; it'll be an option ROM of some
> sort.
Done, I'll see if my programmer can read it once my only working windows box
stops updating itself, sheesh.
> Vcc. I would connect the
> Look for inconsistencies in voltages and pulses to and from RAM. You may
> need RAM at the lowest memory locations to boot. Hooking up the keyboard
> at least to eliminate a missing keyboard as a reason the system does not
The PET keyboard is just a matrix of switches, if nothing it pressed i
dinosa...@gmail.com>
> To: "General Discussion: On-Topic and Off-Topic Posts" <
> cctalk@classiccmp.org>
> Sent: Monday, October 05, 2015 12:27 PM
> Subject: Re: Dead PET4032
>
>
> Hi Tony,
>>
>> The screen's not connected, nor keyboard. I fig
- Original Message -
From: "Adrian Graham"
To: "General Discussion: On-Topic and Off-Topic
Posts"
Sent: Monday, October 05, 2015 12:27 PM
Subject: Re: Dead PET4032
Hi Tony,
The screen's not connected, nor keyboard. I
figured there was no point
until I
>
> The screen's not connected, nor keyboard. I figured there was no point
> until I got a chirrup.
Well, if the piezo buzzer has failed But I guess that's not very likely.
-tony
Hi Tony,
The screen's not connected, nor keyboard. I figured there was no point
until I got a chirrup.
My logic tester is a cheapo Micronta, yes. There's an unpopulated ROM
socket at UD11 so I can easily get +5 and GND from there for probing, I'll
do that tonight.
A
On 5 October 2015 at 16:55,
>
> One chip that does get hot is the Character Generator at UA3 which I was
> going to swap with the one in my other 4032, but that doesn't power up
> either. Presumably I can borrow one from a 3032 or 8096?
A machine with a dead character generator ROM (unless it is so dead as to
pull a power
Hi folks,
Some storage reorganisation last week uncovered a PET4032 I'd forgotten I
had. Spotless internally (I remembered why later) and glass fuse intact so
I attempted powerup. Nothing. No screen and no chirrup.
Google + schematics time. I've checked AC voltage at the iron lump and all
major c
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