olix

2024-04-19T19:36:27Z

Maybe Duddie can take over production, sales and shipping again?

2024-04-19T19:25:06Z

I still have an older V2 PokeyMax (no 2b). This requires 10 uF electrolytic capacitors at the audio connections. Can I use tantalum capacitors instead of the electrolytic capacitors? These would be smaller.

2024-04-19T18:33:59Z

But another big question is: Will the PokeyMax V4 be available to buy anywhere?

For most of us it will be impossible to assemble the board ourselves, even with a little SMD experience these components are far too difficult.

Monday at 09:20 AM

Nice to hear that the PokeyMax success story continues. But what is the goal to be achieved with version 4?

Cheaper than PokeyMax V3?
More and new functions than V3?
Better availability than V2 and V3?

Monday at 06:18 AM

11 hours ago, Mathy said:

... Looks like there's a lot of unused space on the underside/backside. Would it be possible to move the resistors to the underside to make the PCB even narrower?

Mathy

I think you should leave the layout as it is now. If there are components on both sides of the board, it only makes assembly unnecessarily difficult.

You can't save that much space either, because there has to be room for at least the pin header, even if all the other components are moved from the top front to the bottom.

April 13

Overange was kind enough to sell me two of his extra-small UGV boards. As these were not assembled, I first had to get the components and then embark on the SMD soldering adventure.

Assembling the board is not necessarily suitable for a soldering beginner, but with a little experience and patience you can do it quite well. The most difficult part was actually that I had to switch between three different pairs of glasses during assembly: normal glasses for distance, reading glasses for close-up and magnifying glasses for the very small things. And then a microscope for checking.

But everything worked out well and the two UGV modules worked straight away. Overange did a really good job and made the already good UGV from Mytek even better, as it now fits into the 600XL without any problems. I really love this little piece of hardware.

April 12

I am also interested in one ore two front panels for my existing mega speedy.

April 12

Ah, I see. The area around the pokey is really very densely covered with routes*. I imagined it would be easier. The idea with the additional pads is also just a "nice to have" and not a "must have". The idea of using a breadboard area for this is completely sufficient.

You shouldn't change to a 4-layer PCB just for this reason. That would only increase the costs unnecessarily.

I am happy with your board as it is.

*By the way, what is the right word in English for the routes on the pcb : conductor, conductor path or trace?

April 11

I have a small suggestion in case there is ever a new board revision:

In addition to the connections pads for the console buttons, it would be very practical if there were also connection pads for the signals required by a stereo Pokey extension (PokeyMax):

- A4
- GTIA Bell (GTIA Pin 15)

Even better:
A5, A6 and A7 (for Quad Pokey, Covox or similar)

I don't think that would be too much effort, but it would be a great help.

April 5

I have tested 5 more crystals. All purchased from Mouser:

I had the best measured frequency with the ECS-35-30-4X: 3.57934 MHz

Also good results with: LFXTAL016962Bulk and ECS-35-17-4X

Only an grey image (no colors): ECS-35-17-1X and LFXTAL000052Bulk

(All tests without additional capacitors)

LFXTAL016962Bulk
https://www.mouser.de/ProductDetail/449-LFXTAL016962BULK
HC49/4H

Frequency:   3.57945 MHz
Load Capacitance:   30 pF
ESR:   300 Ohms
Tolerance:   30 PPM

Color-Image: Yes
Measured frequency: 3.57923 MHz

---

ECS-35-17-4X
https://www.mouser.de/ProductDetail/520-HCU357-17X
HC-49/US

Frequency:   3.579545 MHz
Load Capacitance:   17 pF
ESR:   200 Ohms
Tolerance:   30 PPM

Color-Image: Yes
Measured frequency: 3.57917 MHz

---

ECS-35-17-1X
https://www.mouser.de/ProductDetail/520-HCA357-17X
HC-49

Frequency:   3.579545 MHz
Load Capacitance:   17 pF
ESR:   120 Ohms
Tolerance:   30 PPM

Color-Image: NO
Measured frequency: 3.57813 MHz

---

ECS-35-30-4X
https://www.mouser.de/ProductDetail/520-ECS-35-30-4X
HC-49/USX

Frequency:   3.579545 MHz
Load Capacitance:   30 pF
ESR:   200 Ohms
Tolerance:   30 PPM

Color-Image: Yes
Measured frequency: 3.57934 MHz

---

LFXTAL000052Bulk
https://www.mouser.de/ProductDetail/449-LFXTAL000052BULK
HC-49

Frequency:   3.579545 MHz
Load Capacitance:   20 pF
Tolerance:   10 PPM
ESR:   150 Ohms

Color-Image: NO
Measured frequency: 3.57838 MHz

April 2

This is my installation: I soldered a socket, so i could change the crystal faster without soldering.

April 1

I have made today some crystal tests. Short story:

My crystal from the german shop "reichelt.de" - only a grey picture on tube tv.

Scope shows 3.57840 Mhz (to low)

same crystal with 22pico on each side: COLOR.

Scope shows 3.57989 (little bit to high)

I had also tested a very cheap crystal from China (AliExpress): COLOR (without 22 pico)

Scope: 3.57915 (little bit to low)

I have ordered some more crystals for testing.

March 31

4 hours ago, Jfcatari said:

@olix

..

What crystal did you use on your build?

I used one from a shop in Germany: 3,5795-HC18: Standardquarz, Grundton, 3,579545 MHz bei reichelt elektronik

With S-VIDEO on an LCD screen, I have a color picture. But I have not yet tested a composite signal or a CRT TV. I will test that in the next few days.

March 31

I also fitted the first board and everything worked straight away. At least almost straight away, because at first everything remained dark - but the error was quickly found: I had mixed up Pokey and PIA. So it was my mistake. Fortunately, the two ICs were not damaged. So I installed the two components correctly: And everything worked.

By the way, this is my first NTSC Atari, since I live in Germany I usually only have PAL devices. I will build the next 800XL Adcanced board in PAL.

@reifsnyderb : Many thanks for your great work and especially for the support with shipping to Germany

March 30

Oh, that sounds exciting. Is there more information about this OS version 6.2 here in the forum?

March 30

On 3/5/2024 at 1:24 PM, reifsnyderb said:

Here's what I have on mine. OS R3 (with self-test banking fixed) and Atari BASIC C on bank 1. Bank 2 should have a pre-release of OS R 6.2 and Altirra BASIC 1.58.

ROM.BIN 128 kB · 18 downloads

What means "self-test banking fixed" and what is OS R6.2 ?

March 28

OK, I understand. Best-Electronics has been an important source for Atari stuff you can't find anywhere else for many years, but its website and listings are not necessarily a trustworthy source of information.

I even wrote to Bradley Koda at Best Electronics years ago about this fault with the frequency of C061090, but unfortunately he never replied or corrected the list.

March 28

I think that the component has exactly the right frequency: 3.579545 MHz

I don't know where you looked, but in the original Atari Service Manual and in many other sources the crystal Y1 is described with exactly this frequency and not with 3.57945 MHz

March 27

I think I have found a switch for the Rom bank (RF switch) SW1 that will fit. Not perfect, but I think it will work:

Apem 25536NA6

Mouser No: 642-25536NA6

The switch has the correct pin spacing and fits into the motherboard but it is a little smaller. However, the switch length should be long enough.

Unfortunately I can't test this as I only have PAL Ataris and they don't have a cut-out in the case for this switch.

March 19

Today I received my package with the 5 circuit boards. It was a collective order for some ABBUC club members in Germany. I would like to say a big thank you to Brian.

Not only did he do a great job with the development of this board, but he was also very helpful in arranging a cheap shipping to Germany.

@reifsnyderb: Thank you very much!

March 19

Does anyone have a part number from Mouser or Digi-Key for a compatible SW1 switch:
ROM Bank (was RF Switch)

I live in Germany and this switch was not installed on the PAL machines. So I don't have a sample to look for a replacement.

March 17

Can I use a 74HCT14 instead of a 74AHCT with IC U19?

What is the difference?

March 15

Did I understand correctly that the number of reresh cycles (128 or 256) only plays a role with DRAMs?

So if I use a 64K extension with SRAM, like the one from Lotharek, it shouldn't matter whether I use the older ANTIC with 7-bit refresh counter or the newer one with 8-bit refresh counter? Is that right?

March 13

How do i know, if the ram is a 128 or a 265 cycle refresh type?

March 5

Is this project still alive? If so, will it be possible to purchase a PCB or are the Gerber files available to make the PCB yourself?

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