Jeff_Birt

I found some from an Atari KB which have a different shape to the top of the key stem than the Epson HX-20. The HX-20 uses the standard + shape. It works out as I need to adapt some keycaps from the 'non-repairable' HX-20 keyboard anyhow. It is interesting that these switches were made by Cherry until the early 2000s but there seems to be no surplus of them.

I'm looking for some Cherry M8 (not MX) key switches, the open top SPST variety in particular. These were used on some Atari keyboards as well as the early Epson HX-20. Found a place in Canada that had some but the shipping was outrageous to the USA.

Bleaching does not 'shred its essence away', it changes double atomic bonds into single bonds, altering the 'shape' of the chromophore altering the wavelengths of light if reflects therefor changing its color. Again, gone into in great detail in the video. Please don't create more myths. The effect on human hair by bleaching is a different subject.

Well, here is the rub; if you actually watch the video or read the paper you know why that conclusion was reached. There is nothing magical about bleaching it is a well understood chemical process that alters the atomic bonds in the molecules. Again, watch the video and you would have learned that too...

Some folks have tried this and had no luck. I think the number of ions generated by an ozone making apparatus is orders of magnatude less than that which occurs from H2O2 decomposing.

Yes, I made the point in the video that the choice of the bleaching agent depends on the job at hand. Bleaching your socks is a different job than bleaching paper pulp. And yes, carbon electrodes would have been a big benefit. The electrolysis rig ran long enough to show that the exposure to the hydrogen or oxygen gas alone had no discernible effect.

The truth about Retr0brite – busting myths with science… One of the situations we are often faced with when restoring an old computer is a yellowed plastic case. You have probably heard of Retr0Brite, few things in the retro community have caused as much controversy, rampant speculation and unfounded opinions as this subject. While there has been a lot of speculation and theories passionately bandied about on this subject there has not been an effort to understand the process. A combination of research and practical experimentation was done to try and answer the questions: What it is Retr0Brite doing and what is it doing, or not doing, to the plastic. We will discover where color comes from, what plastic is, what makes plastic yellow, and what Retr0Brite is actually doing. This video is the result of an effort to get to the bottom of the matter using a scientific approach. I ask that you please keep an open mind and watch through to the end of the video before banging out a comment on your keyboard. https://youtu.be/YPl356YKcVs

This video started out with a simple mission. To investigate the Suncom 4-button controllers used for ‘The Party Quiz Game’. These odd controllers use the paddle inputs, so this set off a quest to learn how the paddle input worked and how to read them. Along the way we wind up characterizing the response curve of the SID’s POT inputs, comparing those to the Armsid, discovering a problem with the Armsid POT inputs on a few of the very first PCBs, fixing that with an experimental firmware update. It was a lot of work, and a lot of time spent collecting data, but it was also a lot of fun. Top finish things off we look at the surprising number of input devices that made use of the POT inputs. Who knew there were so many? Thanks to some folks on this forum for pointing out some of these devices. Join us…

Here is the new list: Input devices that use POT input: · Paddles · The Party Quiz Game 4-button controllers · Atari CX85 keypad (POT Y used as digital input) . Cardco Cardkey Numeric Keypad clone of above · Atari CX80 track ball can use analog (mouse) or joystick (digital) modes · Atari driving controller · Atari Video Touchpad (Atari 2600 for Star Raiders), can use on C64, etc. · Atari Touch Tablet CX77 · C64GS joystick (Cheetah Annihilator) uses POTX as digital input. · Commodore 1351 Mouse · Koala Pad · Mssiah (uses external pots for controls) · Vaisala HAWS weather station · Security dongles · Muppet learning keys, Kids Computer Keyboard · RCFS 64 Commodore 64 Dave Brown R/C Flight Simulator Dual Joystick · Suncom Animation Station

Since the C64, Atari and Apple were made to accept very different paddle resistance ranges (470K, 1meg, 150K respectively) I suspect Koala Pad was configured to work with each device to get the maximum resolution.

I just learned from someone on Facebook that the Atari CX80 track ball can use analog (mouse) or joystick (digital) modes. The Muppet keyboard in a new one though. I wonder if it was released for other systems as well?

Quiz - What input devices used the paddle, i.e. POT inputs on the Atari or C64? Below is a list I have compiled with help from folks on Twitter. This question came to mind after I spent a lot of time to characterize the input_resistance/byte_value curve of the A2D converter on the C64 SID (which is nonlinear, spoiler alert, and I suspect the POKEY POT inputs are equally nonlinear). The exact response curve does not matter for paddles or mice as you are moving them in proportion to what you see on the screen. For a security dongle or the 'The Party Quiz Game' controllers it might make more a difference as they expect a certain resistance to result in a narrow range of readings from the SID. Input devices that use POT input: • Paddles • The Party Quiz Game 4-button controllers • Atari CX85 keypad (POT Y used as digital input) o Cardco Cardkey Numeric Keypad clone of above • Atari Video Touchpad (Atari 2600 for Star Raiders), can use on C64, etc. • Commodore 1351 Mouse • Koala Pad • Mssiah (uses external pots for controls) • Vaisala HAWS weather station • Security dongles

Thank you! Somehow I completely missed the ICD clearly written on the chip. If it had been a snake, I would be a gonner

Thanks, but is 'this' Rockwell chip actually 'the' US Doubler ROM? (I know the top chip in the first picture is an 'A' version Atari ROM.)

I bought a bunch of Atari goodies recently and in one box there was an old pill bottle labeled 'ROM B'. Inside were three ICs, one of which was actually a 'ROM A' not a B rev. The other two puzzled me for a bit until a friend on Twitter mentioned SpartaDOS. After finding the post below I was sure that the encapsulated module was the SRAM and guessed that the Rockwell chip was a ROM but I am unsure of if this is the original Atari 1050 ROM or the 'US Doubler' ROM. Searching based on the part number turned up nothing other than one other post wondering what the chip was too (although he did read it out so it is a ROM). I will try to read the ROM but as hoping someone might be able to identify it by the part number so I know what to try and compare the ROM dump to. Thanks!