Falcon clock patch V4 series

[exxos]

I've been asked about this patch a few times over the past few weeks. I did write a roundup in my blog but I think it is probably got missed.

I think it is important to realise is what the differences are between the V2, V3, V4 designs.

Firstly the V4 series looks like this.

v4.PNG

This part replaces the V2/V3 style boards.

However, it is important to realise that in terms of bus speeders and overclocking, a otherwise nonstock Falcon ,this board alone does not replace the V2/V3 series.

The reason for this is that the V4 does not have a built-in delay like the V2/V3 board does. The delays are actually offloaded onto a separate board which I call the "part 2" board. Which looks like this..

2.JPG

Where this "part 2" board has steps of 10ns delays for people to experiment with bus speeders. However this board may or may not be on sale depending on how my beta testers report on it. If it has no advances over the previous V2/V3 delays, then it is somewhat pointless putting this board into production. However I may ultimately put the prototype boards in the store to recoup the money spent on the project. Tours may ultimately still be useful for people who want to experiment. At this point I have no idea.

So to round up:

V2 = Stock Falcon or bus speeders with 2 SDMA delay settings.
V3 = Stock Falcon or bus speeders with 3 SDMA delay settings.
V4 Part 1 = Stock falcon With improved clock drive and immunity capabilities.
V4 Part 2 = 4 10ns buffered SDMA clock delay.

So if the V4 part 2 board has no advantages then the latest board will fall back to the V2/V3 series of board and I will just simply discontinue the "part 2" V4 board.

If anyone is confused then if you have a stock Falcon, then the V4 will be the latest board you can use. The problems only arise with combinations with people with otherwise nonstock Falcons. IE using bus speeders.

I will however continue to produce the V4 as it is a much improved design over the previous series. I am currently unsure if I will discontinue the V2/V3 series currently. Not sure it's really worth continuing them as they only have the delay options built on, which are only useful for bus speeder experimenters, which I doubt are that many these days and probably already have a V2/V3 by now anyway.

I am hoping the V4 part 1 will be in store over the next couple of weeks. I had to revise the board a couple of times because wrong parts ended up being fitted :( So the whole thing got delayed somewhat.I do need to try the final board in my own Falcon before they hit the store. I am somewhat limited on time which work currently.

[Rustynutt]

Been cleaning out the computer room while waiting for the postman :)

[exxos]

Been cleaning out the computer room while waiting for the postman :)

Surprised it hasn't got there by now :(

[Rustynutt]

Been cleaning out the computer room while waiting for the postman :)

Surprised it hasn't got there by now :(

The room was really really bad :)

[Rustynutt]

A bit late to the game, with the V4 now in hand will start testing soon.

First data results will document variables using a standard Falcon before moving to a CPU on the expansion bus.

The base really only has 2 options, with/without FPU, and variable main oscillator selection.

Maybe give me input if it's worth while testing with and without the FPU.
When the Afterburner 040 is installed, the setup isn't easily changed to run like the CT in "Falcon 030" mode. That setup I usually don't have the 882 installed as it's not really even redundant and just uses power. Then not everyone is using a CT, much less an AB040 :)

Only deviation I'll have to make is at what point the V4 DMA boards clock output ties into the DMA clock input.
This is the Falcon I'd broken the CLKEN pin and had to trench down to metal to tie in a connection. That lead is about 2cm. I jumped it around the dog leg of the DMA clock trace, and tied back onto the trace just right of the floppy header.

Have to keep solder points at that distance, else risk the solder point on the DMA to melt.
It might be a good time to try skills at replacing the IC, I'm "fairly" sure I can, at least and not damage anything. But as it works fine, I've not be keen doing so :)

In the past, usually do a lot of big file transfers over the SCSI bus using Kobold and rely on its companion apps to test data integrity. Exercise floppy test, and run the green bar DMA test app.
Don't have a musicians ear, other than severe Tinnitus, may not be as sensitive as others listening for "crackle", from what I recall, audio output is good on this machine.

Criticism is much appreciated :)

[exxos]

I think the crackling is pretty apparent in ace tracker.

Indeed don't change the DMA unless there's no choice. Damaged pads will turn into a nightmare.

[Rustynutt]

I think the crackling is pretty apparent in ace tracker.

Indeed don't change the DMA unless there's no choice. Damaged pads will turn into a nightmare.

I can surely at ace tracker to one of the test.

Opinion on leaving an 882 installed in the socket or not?

One favor, can I easy mod my CT variable clock to output a lower frequency, like 40-50MHz?
I may of damaged the trim adjuster by running it too far out and in. Think there are some left yet in your store.

[exxos]

Opinion on leaving an 882 installed in the socket or not?

Probably won't make any difference.

One favor, can I easy mod my CT variable clock to output a lower frequency, like 40-50MHz?

I don't think it would be simple, I never really intended people to use a slower than default clock, I'm not even sure if that would even work.

I may of damaged the trim adjuster by running it too far out and in. Think there are some left yet in your store.

Those modules sold out a while ago. I may be able to find the part number of the pot but probably be easier just to measure the end-to-end resistance and just look for a 20(ish) turn pot which looks the same.

[matt.lacey]

Appreciate this post, I was reading up on the clock patches recently and got a little confused. Will wait til this one hits the store since I'm running stock!

[exxos]

Appreciate this post, I was reading up on the clock patches recently and got a little confused. Will wait til this one hits the store since I'm running stock!

You may be better with a V2/V3 as I am not sure when/if V4 will go on sale yet.

https://www.exxosforum.co.uk/atari/store2/#0073