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Could you post some screenshot samples of the GSP GUI main screen, arcade screen and game details screen? Might be able to use them.

Just follow all the traces in the wiring for the 156. It goes to the 138 and the 259. The 156 is important it what gives you the rambo option and allows the ram to appear at the 6000 space in 8k chunks instead of the 5800 space in 2k pages. Also maybe the reason that led lights up right away when you turn on power if that circuit is messed up. As for the little circle it just means the line is active low, enabled, don't worry about that just map out the lines see my screenshot best to view it via a large screen not the mobile or print it out the schematic.

Do you think you also might be able to, while you are at it, open the GSP firmware in MiniGUI and edit it a small amount to change the buttons and add some libretro cores to its database for us GSP gamers? I could mock up some visual ideas for modifying the GUI.

Oh, this is fantastic, and at such a low price. Thanks for the link! -Ben

Like the others, I also thought that Atari800 used to emulate this but couldn't find any older builds that did so. I took a look at the Atari800 SIO and sound code and it looks like the existing SIO sound approach would need to be reworked. Fundamentally, the characteristic Atari SIO sound comes from the way that POKEY's serial port interacts with timer 3 and 4, particularly in asynchronous receive mode. This is a scope of when the Atari is transmitting a command frame over the SIO bus, specifically a type-3 poll. This is the farting you hear after DOS 2 boots or when no bootable devices are connected. CH1 (yellow/TX) is SIO DATA OUT, CH2 (cyan/RX) is SIO DATA IN, CH3 (purple) is audio out. During a send -- SKCTL=$23 -- timers 3+4 are continuously counting to provide the transmit clock for any bytes that are queued to send. It runs continuously regardless of whether a byte is actually being sent or not. Timers 3+4 are configured for a period of 1/38400th of a sec for 19200 baud and the OS configures channel 4 for square wave output ($A8), so the output tone is 19200Hz. This is inaudible, so the primary component heard is the change when timer 4 starts and stops, and not the tone output itself. This is also why the tone starts a little bit before and some time after the actual command frame bytes, since it depends not on the end of the last byte but when the SIO routine in the OS gets around to reconfiguring the serial port. Each command sent produces a single "putt" of sound. The farting noise comes from the OS SIO routine retrying the type 3 polling commands 27 times, with a timeout driven by OS timer 1. This is VBI-based with a timeout of 2 vblanks, so the puttering occurs at 30Hz for NTSC and 25Hz for PAL. During a receive, SKCTL is changed to $13 to enable asynchronous receive mode: This mode sounds a lot different than transmit because of the way asynchronous receive mode affects timers 3+4. In this mode, POKEY has to synchronize to the device's transmit clock, which is out of phase with POKEY's serial clock. Therefore, in this mode, POKEY holds timers 3+4 in reset while waiting for a start bit, and those timers don't run. At the leading edge of the start bit, timers 3+4 are started, and then count off half-bits in phase with the transmit clock so POKEY can sample in the middle of each bit. Upon sampling the stop bit, timers 3+4 are stopped again to wait for the leading edge of the next start bit. This process causes timers 3+4 to underflow and fire a pulse to the audio circuit 19 times -- which crucially is odd. This means that the output bit is toggled at the end of each byte, which you can see above in the gaps before and after the ACK byte ($41). The result is that the audio output has a fundamental square wave at half the byte rate of the transmission, with bursts of inaudible 19200Hz on top of it. The fundamental frequency varies based on the device, a bit higher or lower than the nominal 960Hz depending on the device. 810s, for instance, produce a slightly higher pitch than a 1050. Note that the byte rate is not the same as 10 times the bit rate, as devices often have a bit of a gap between the stop and start bits. It also means that the tone doesn't depend on the computer's clocks, which means that it is invariant to NTSC/PAL. What Atari800's SERIO_SOUND appears to be doing is rendering the 10 bits for each byte at channel 4 volume -- 1 start bit + 8 data bits + 1 stop bit. There is often a component of this in the audio output due to the SIO data leaking into the audio output, but it's faint and not subject to POKEY volumes. It's what you sometimes hear when a loader shuts off the main SIO sound and you hear still hear tinny buzzing during the sector loads that varies a bit in timbre depending on the data bytes being received. That's not the same as the stronger transmit/receive effects above, which are independent of the data bytes being sent and received. As far as I can tell, the sio.c/pokey.c/[mz]pokeysnd.c don't implement timers 3+4 being held for asynchronous receive mode, which is a main requirement for emulating this effect. Probably the simplest starting point would be to override the connection from timer 4 to audio channel 4 and drive audio channel 4 at 0Hz/960Hz when asynchronous receive mode is enabled, running it only when bytes are being received. It's an approximation but would go pretty far towards something representative. More importantly, it's compatible with cheaper asynchronous audio, so it's easier than the next steps of either properly starting and stopping timers 3+4 during async receive mode or driving audio channel 4 with machine synchronized timing. AFAICT Atari800 isn't set up for the latter anyway because it doesn't actually emulate device transmit timing -- it instead sends bytes at the rate that POKEY is set up to receive them, which is not accurate but works most of the time (though it allows some bogus configurations like receiving at the wrong baud rate). The majority of SIO devices send bytes back-to-back at a consistent pitch, though, so it's not necessary to emulate at that level to attain representative pitch. The nominal pitches for receiving from the 810 and 1050, based on the controller clocks and firmware loops, are 943.4Hz and 910.75Hz.

[Windows App Supplemental : Folder-based file triggers] If you want to optionally use folder-based file triggers to run alternative libretro core libraries, without needing to create database trigger records, or in addition to using database triggers, see the documentation include with this zip file. runme-056b.zip

A highlight of visiting a new city is when the wrong way turns into an unexpected treat. I still fondly remember wandering around a deserted part of Naples only to end up at the best dinner and service I had the entire trip through.

I need help determining a graphic on the schematic. I’m using the schematic diagram here and I found a lifted pcb feed to one of the 74LS156 pins tied all together so I’m checking other pins but can’t determine what the open circle is at pins 1, 14 & 15. Thanks for the help, that pin 14 of U7 goes off and should trace to pin 12 of U12 but I’m uncertain about the open circle and my boards don’t seem to trace to that pin.

The mystery deepens with the companion Space Raider.

Alright, but what if I want to use this in a live performance improv setting? Can I at least mute drum and synth sections and whatnot? Another thing I should note is that I'm probably gonna test this on a RetroN 77. The BW/COL button is in the back in that design and I might need an alt button to play sequences, like the RESET button for instance.

Did you get it to work? The bluescsi V2 is it internal? 50pin or external DB25. I am trying to get my external Bluescsi V2 working on my TT and no luck so far.. Term out or in. James

Nice work. Thanks for the update. The keycap adapters are always going to be the trickiest part to get right - the tolerances are very small. Mine worked well in PLA. I've since tried PETG and have found the retaining bumps on the adapter stem do seem to wear down. Is the main issue the connection of the adapter to the switches? or the keycaps? It sounds like the switches, but if it is the keycaps, the spacebar-specific adapter might work better. The only difference is the retaining bumps on the stems are 0.1mm larger. I might try and pick up a few different brands of switches to try as I've only tested the Akko switches linked in the repo.

I thought I would show these from Rockman: Deus Ex Machina:

I'm having an issue where now sometimes the power led flashes when power is plugged in.I can unplug it with batteries and it stops. Then it will be fine for a while if I plug it back in. Think I need to get in there and reinforce it.

Agreed. I should probably clarify that my intention in referring to the mod as 'prehistoric' wasn't a dig at Best (or Brad), but rather a description of the mod itself. It could have come from anywhere and would have still received the same description. Nothing wrong with the mod itself (though I do still believe it to be more involved than necessary compared to newer offerings); if it's what someone wants to use, that's their prerogrative.

Who What Why Which When...These are all just W Words.... Speaking of Which, When...We always seem to forget poor When, and When We forget When We might ask Why? Who (do) We ask Why about When you Wonder? Well, While We...Wait! What? Why ask Why When you can ask What Who Which When or just Wonder Why not I Wonder then Which Wanderings do cause you to Wonder Which and When but not Who of course because Well it's a miracule Who sounds less like a W Word and more like an H Word Whereas Whereas is a W Word Where the W is followed by an H...Hot Damnit!

Got these today...

I would classify the 1200XL keyboard tactile feedback as excellent.

I don't have any strong leads, but anytime I hear about a reproducible "after several minutes" kind of problem it makes me think of heat. If you reset the console immediately does the problem happen sooner next time (vs. turning it off for a while before trying again)? Does the VDP still have its heatsink?

I have the Unijoysticle too. I use it with my PS4 controllers. Really fun with Robotron and Space Dungeon!

Excellent, i'll keep this in mind.

I connected pin 5 and pin 7, and it has been working perfectly for years. It actually works for games that support two buttons.

Episode 73 – Not Just A Knockoff! Greetings and welcome to Episode 73! In this one, Brian recalls a nice little haul he got one Christmas, and gives an Atari 2600 classic the full treatment. If you would like to contact the show, you can send an email at arcadeaddictbrian@gmail.com or you can leave a voicemail for the show at 734-623-0832. The show also has a Facebook page, and is also on Instagram, Twitter, Threads, Bluesky, TikTok (when I have videos) and Tumblr. All of these links can be found at https://linktr.ee/arcadeaddictbrian. I am also putting the back catalog on Youtube as well, a little bit at a time. Just search for arcadeaddictbrian or the podcast, and you will find them! You can help the show by leaving a five-star review wherever you listen to it, which helps other people find it. If you want to help the show directly, go to https://podcasters.spotify.com/pod/show/coaa and click on the Donate button. For as little as a dollar a month, you can help the show develop further as a podcast, as I use those funds for things directly related to the show (buying podcasting and streaming equipment, and funding arcade runs to new locations to review). My deepest thanks to Kevin Hoffman and Benjamin Broedel for their continuing support! Without your help, I would not be in the position I’m in! And now, I’m streaming live on Twitch! Twitch.tv/arcadeaddictbrian. If you’re a listener to the show, please do me a solid and drop me a follow over there. That helps grow the stream, and who knows, maybe I might become a big-time streamer! A guy can hope, right?? Discord server coming soon! Hope to hear from you soon, and good gaming out there! Story Time – Christmas 1987: My own Commodore, a Color TV AND a VCR?!?! Are You Experienced? – Megamania (Atari 2600) Time For Some Stragedy – Megamania (Atari 2600) https://podcasters.spotify.com/pod/show/coaa/episodes/Episode-73---Not-Just-A-Knockoff-e2irlrt

Another bluetooth dongle that works is the Unijoysticle. I've been using it with an xbox one controller and even with the Atari VCS controllers. Neat thing is you can use one xbox controller as 2 joysticks.. so that playing Robotron is easy. There's a list of what wireless controllers will work with it. https://github.com/ricardoquesada/unijoysticle2/blob/main/docs/user_guide.md

Thanks for posting this. I just downloaded it and spent some time playing it with Javatari. Great fun!