Powertran Cortex

[PokePeek]

Hello everyone,

Cortex Mk1 owner here, I built the machine when it first appeared. After many years in storage in the attic I tried it this week but unfortunately it no longer fires up.
My machine is very basic due to lack of funds at the time, it has the cassette interface only.
Are there any resources that might assist me with fault finding ? I looked through a lot of this thread but it takes a while
What I've tested so far;

1. The power supply is all okay
2. 12MHz clock pulse is okay
3. continuity of chip pins to PCB are okay

Currently the BASIC LED is constanlty ON
The MEM LED flashes once after power is switched on
IDLE LED is OFF and does nothing
RUN LED goes OFF when REST button is pressed then comes back on very dim.

Any help would be very much appreciated.

Doug.

[Stuart]

Hello everyone,

Cortex Mk1 owner here, I built the machine when it first appeared. After many years in storage in the attic I tried it this week but unfortunately it no longer fires up.
My machine is very basic due to lack of funds at the time, it has the cassette interface only.
Are there any resources that might assist me with fault finding ? I looked through a lot of this thread but it takes a while
What I've tested so far;

1. The power supply is all okay
2. 12MHz clock pulse is okay
3. continuity of chip pins to PCB are okay

Currently the BASIC LED is constanlty ON
The MEM LED flashes once after power is switched on
IDLE LED is OFF and does nothing
RUN LED goes OFF when REST button is pressed then comes back on very dim.

Any help would be very much appreciated.

Doug.

Hi Doug,

Do you also go by the name of Thomas, who sent me an e-mail on exactly the same subject? Or has the unseasonably warm weather got two old Cortex owners to drag their machines out of their attics?

I'd suggest the first step is to test the DRAMs, as they seem to go bad fairly frequently. If you want to send me a PM, I'm happy if you want to post your DRAMs and EPROMs to me for testing in my Cortex, to help isolate the fault.

Stuart (in the UK)

[PokePeek]

Stuart,

Many thanks for your message, yes it's the same person, what's the chances of two ?
I sent you an email because I thought my first post here had failed to pass the "Moderator Test" having taken several days to show up.

That is a very generous offer to test my chips and I will send you a PM now.

Many thanks
Doug.

[JGardner]

I was wondering what happened to the Cortex crowd... "

Jack