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Hmm... Clever use of +5v card edge to power a "Default closed" transistor bridge maybe? (When power is on, +5v is hot, which drives the transistor to open the connection, and prevent direct short to ground (of address and data pins). When power off, the transistor stops working, and discharge to ground happens instantly. It takes time for a human to power off the unit, then reach for the switch. Unless you put a load limiting resistor on too, the caps should discharge before you can turn the knob? Add diodes to prevent voltage bounce on +5v, and to prevent bounce from saturated ground back into connected devices?) There will need to be a custom cable end put on anyway. Such a thing could be integrated there.

hmmm.. True enough. A transistor based switching array might work better, but getting full bidirectionality might be a trick. Is there a sensible way to properly conduct a ground for the discharge path? There would be extra conductors in the DB50 cable. Redundant grounds for such protection should be doable?

As long as he makes sure that he only toggles the switch with the power OFF, it should be OK. (Flipping the switch with it on is equal to yanking things out of a card slot, and shoving new things in, on a modern PC. Bad Juju.) The idea is to take wear and tear off devices by removing constant insertions/removals. Instead you can turn a knob and have the same effect. JUST DO IT WITH THE POWER OFF.

From what I was reading, the IO timing with the Pi is pretty tight. It might have been the GPIOs being in a "not-sane" state.

Here we are! DB50 rotary switch. https://ppeci.com/index.php/products/detail/d-sub-switch-box That should handle every line from the sidecar port, and then some. You would need special DB50 to sidecar card-edge cables, but afte that, it should be cake?

I remember there being some "IO Switch boxes" in the 90s that could do a DB25, a VGA signal, and 2 PS2 interface connectors between 2 positions. (In comparison to the simple DB25 boxes you can still find) One of those, with some jiggery pokery, could do the trick maybe?

It could be a useful area to store volatile data; Say for instance, you have a program that sends some kind of datagram to a TIPI regularly, that is generated by some small bit of program code, but you dont want to always be executing the code that generates it, because of the limited stack space available. Instead, you generate out the whole stream, then reduce your sending code to "read X byte sequence from volatile file X, send to tipi TCP Raw handler" etc. It would be useful for midi music scores (which could be packed with a compression algo pretty nicely, but you dont want to lug that in your main process) and the like.

Quick and easy Just use the hostname command. http://man7.org/linux/man-pages/man1/hostname.1.html

now if the actual minimem's DSR was updated to support the banking, that would be a real treat. (256kb ramdisk, without touching the 32k area!)

As HomeAutomation points out, you need a way to switch banks. The whole cartridge width is 8k. To bank on a hybrid cart (ROM + RAM) you do a latch on write to the ROM area. This tells your latch what part of your SRAM to expose on the window. This is the banking scheme used by the FG.

Some items only exist for the PEB. Things like SAMS cards, or the Geneve (and most likely, ultimately the Geneve clone i hear FarmerPotato is working on).

This is very useful! If possible, i would take your images and highlight areas i would like measurements on. I can actually reverse engineer a flat pattern for the sheet metal components if i get some key measurements. Since this is sheet metal, I need some small bits of detail not provided-- I need nominal thickness of the material, and the outside corner radius of the bends.

Soooo.... For DC-DC converter based PSUs, like PicoATX, is this rating applicable at the PSU board itself, or does it include the wall wart?

The supercarts are an E/A cart, with an 8k ram bank tacked on. It might be possible to manually doctor an E/A cart image so that it makes the FG99 act like a supercart when loaded. See this quoted section So, if I am reading this correctly, if you took the E/A cart rom set, doctored the magic byte so that it contains "R", and then tacked on a second filename ending in D.bin of the size of RAM you wanted, it theoretically would function as the supercart... I think.

Nevermind, I am a tool. The minimemory only does 4k, and does not bank switch. The page I quoted from has some caveats that says that the RAM that gets emulated needs to be preloaded to be available, meaning it has to be in the image file. The minimem does not have this second requirement, so wont work. I am not finding a suitable dump for the supercarts. Does anyone have one?

From the FinalGrom99 website: So, since there isn't an option to specify the RAM size (always fixed at 512kb!), just load mini memory cart image.

Sadly no. I am landlocked in the most inconvenient place in the contiguous US states-- Central Kansas. Where there is neither culture, nor appreciation for old things.

Hey folks, I have decided to embark down a path of projects to benefit this community by making complete fully dimensional drawings for (and CAD models of) all the enclosures used by this system. However, I do not own a PEB, therefor I cannot make such for that item. Can somebody whip out some calipers and give me some dimensions? What brought this on: I have seen some suggested projects that would require this information (Laptop convert of 99/4A, new shell for 99/4A, cartridge replacement shell, etc..), and I have noted a lack of good dimensional drawings for these components. I happen to be a trained industrial draftsman, and can produce these for most of these items myself without help, but I do not own a PEB. I also own a (cheap, Chinese knockoff) 3D printer, and I did some CAD experiments on making easily printed, "Interlocking" parts, that could be used to create printed versions of these items, with some effort. This last bit is a moonshot, but the former I can totally do, no trouble. If somebody has a PEB that is already taken apart, and has a pair of calipers-- Take some photos and scribble your measurements on the pictures and post them. I will make CAD drawings.

Currently: Commodore 1702 Reason: Free acquisition, decent picture

Given the number of things that need a PEB, I am toying with the idea of building my own. (Seriously, with how much those things cost to buy + ship, it would probably be cheaper for me to just design and build one myself.) I just havent reached the critical threshold to get over my natural indolence.

You know, I am kinda surprised nobody has attempted to make a new generation geneve. There are at least 3 projects I know of that attempt to recreate a TI 99/4A, either with discrete parts or with an FPGA.. Yet no Geneve clones? I find that odd.

Well, I mean, I TRIED calling their contact number, but they told me they had no idea who TRONICS was! 2563 East Loop 820 North, Fort Worth TX 76118, 817-595-1202 Surely they would have been happy to take my money and send me my own copy, but noooooooooo

Well, if the copyright scares you, you could always try to look up Mike Wilcox and Dave Guardanapo The people behind TRONICS, who would be able to give you permission... OR, you could just rest easy knowing that TRONICS sales and distribution went out of business a long time ago, and just send me those wav files.

🤣 Sorry, but I cannot make a review by pulling a Johnny Carson with a printed image of your cassette.

Such procrastination! Much inaction! WOW!