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I see you have found some DIN connectors. If you run out, I may have access to some. I think I have right-angled male plugs (solder type) and straight female sockets (push fit).

I bought 7,500 for...

Assuming RDx is the RAM Data, then the logic analyser is indicating potential problems somewhere...

Unfortunately, a logic analyser is no good for looking for this type of potential fault. You...

Getting there ...

Dave

This is the best photograph of the top of the buffer board I have been able to find:

https://www.worthpoint.com/worthopedia/rockwell-aim-65-early-computer-buffer-2001589385

1 * 245 (data bus...

I suppose it is also worth pointing out that there are two (2) +5V regulators (and, therefore, two +5V rails) on the PET 2001N.

Obviously, both dc supplies need to be within tolerance for the PET...

The AIM-65 is supposed to interface to the serial world via a 20 mA current loop.

However, with the addition of an RS232 transmitter buffer, it can drive an RS232 device as per the following...

Post #28 should cover the rail voltages.

Worth double-checking them though with an oscilloscope - looking for dc level and ripple/noise.

That should put the rail voltage issue to be fairly...

Tom,

Yes, the text "write" appears to be hard-coded where the warning appears - but the previous messages correctly identify the transaction as a read.

Does this imply there is a fault...

Those traces look fine to me (on a quick check at least).

As you can see, triggers are the all important factor with both an oscilloscope and a logic analyser. If you suspect that a write is not...

>>> On my Straight 8, PAL opens the side panel and an arm with an open hand reaches out and slaps the programmer silly.

I can think of quite a few machines where this optional add-on would be very...

There is a file on the disk called CHESS.TXT. Suggest reading it... It is also here https://technikum29.de/de/lernprojekte/schach/Chekmo%20II%20%28english%2C%20original%29.pdf.

The error you are...

There might be a clue here.

https://raymii.org/s/articles/Creating_an_OS8_RK05_system_disk_from_RX01_floppies_for_the_PDP-8_with_SIMH.html#toc_2

Dave

Hi Greg,

You need to be a little bit careful with what you are looking at on a scope / logic analyser. You need to know what is happening on the CPU at the time interval you are specifically...

Forget the drive for now - and concentrate on the PET IEEE port.

As I stated back in post #3, we have already gone through a process of hand-testing a PET IEEE port using a bit of BASIC software...

There is another very recent thread on the forum where we did exactly this and tested the IEEE port in isolation from anything else.

The other thing to check is that you have the IEEE cable in the...

Set ourselves the goal of getting space invaders running!

Dave

One of the documents I read yesterday I am sure had the bit patterns for the character generator in it.

Dave

Well done that man :-)!

Have you tested all of the PET functions yet?

Do you have a cassette to load space invaders for example!!!

We have had people get this far - and then something else...

I fired up my AIM-65 emulator this afternoon and I found that it already contained the AIM 65 DOS VERSION 1.0 ROM image.

I remember now what the problem was - I couldn't make sense of the ROM...

I was merging the screen display from the other 'half' of the EPROM - but I am not making much sense of it...

Can you just confirm the wiring of the adapter board that you made up please?

There...

I am guessing (from looking at the photograph) that there are two parts to this.

1. Is an adapter from the expansion bus to a ‘commercial’ bus.
2. A video card for the ‘commercial’ bus.

I...

Nice purchase!

Dave

I can't answer that question though.

Is there a -9V generator on the board?

Presumably you can follow the -9V pin(s) from the EPROM to where it is sourced from - and see where it takes you...
...

Excellent work Tom.

Dave

This information is from soooo long ago!

Use the Windows Installation disk.

Answer the language and time questions.

Click Next.

Select Repair your Computer.