ISA Blaster: A software-defined ISA card based on a Raspberry Pi Pico (Part 1) 

I thought you chose the pico because of the PIOs, which is *the* reason I would choose it myself. You can just put the bits in the PIOs' FIFOs and shift them out as soon as they detect a read, or something like that. You can do that from Python, no need to compile anything.

Very nice project. I played with Pico Pi on my XT prototyping board a year ago, but it turned out to be too slow to use it directly to ready from the bus, I ended up with programmable logic ICs which can be setup by the Pico Pi to react on particular combinations and only send an interrupt to the Pico Pi. That works much better, but I never came over a very rough prototype though. Such project needs a lot of time, so great job!

I was hopping for a Sound Blaster Clone 2 in 1 type of ISA :)

What an interesting project. I hope you'll find other cool uses for it in the future, there's so many possibilities with interacting with an ISA bus in software.

I have been wondering about this for quite some time. I'm glad somebody took up the challenge.

Loving this so far!

Very cool, I've spent way too long browsing vogons looking for a good solution for modern mice on old hardware. Looks real promising. The possibilities are interesting, WIFI/LAN, USB, MPEG Decoder, XT-IDE boot ROM, RAM, sound. Love it!

Sir, you are an absolute wizard.

Really cool. Nice job.

I just watched a crazy person at work. Only thing that bothers me is that I understood every word. Good job!

Love your voice! Keep up the good work my dude

Awesome project!

Well done! Great little project. Unfortunately, I have no ISA bus machine any longer. However, I can see the necessity for this device to keep the old software usable.

ISA cards still exist, but (modern) motherboards with ISA slots are hard to find. A better project would have been an ISA adapter to PCI bus using Pico, emulating a soundblaster ;)

Great work!

Nice step towards making fully open sourced computers.

You made yourself a bus mouse. I remember having one of those on an old IBM PCXT compatible. It came with it's own ISA interface card which was good because the serial port was occupied by an external modem.

DirtyRat, I love it! Great work and I hope you get the LC/RC issue worked out!

Very promising, nice video clearly upcoming youtube star.. really going all in, and im loving my seat here watching ;) thanks a lot for doing these very interesting things and share with us.

You beat me to it. I was thinking of doing the samething with the pico.

This is amazing. Cant wait to see more. A couple ideas. I have no idea how feasible some of these would be. 1) emulate a boot rom that could load boot ROM images something like XTIDE. 2) anoter person already said a wifi version to provide network connectivity. 3) USB storage? 4) and of course....it would be so awesome if it could do some sort of sound emulation. This moght not be possible for thr picos cpu but i figures id throw itmout there.

thanks for the video!

Great idea, I believe that we can replace most of the ISA cards with devices like the Pi Pico

I'm also looking at using a Pi Pico to emulate devices for 8-bit micros. Using 74LVC245 chips not only takes care of level shifting, but also multiplexing, allowing you to connect both the data bus and the hi/lo parts of the address bus to the same pins on the Pico (using just one extra control line for each set of 8 lines). The Pico should be fast enough to handle back-to-back transactions if you allow for it in the software design. That is, check for the second right after handling the signals for the first (instead of treating them separately). Note that if you run out of GPIOs, there are RP2040 boards that bring out all 30 GPIOs the chip has to offer. Also, if you check out the "Hardware Design with the RP2040" document, you can see about VGA and audio output using the Pico.

Thanks for doing this .. now I can build a PicoPC with _all_ RPi Pico substitues for various parts of x86 PC (including the CPU)

Excellent!

Cool video.

Great stuff thank you .

That looks awesome! However, if you intend to move the board around a lot (for debugging etc.), I would suggest using a beveled edge and hard gold plating

Looks like you know your onions, however, I completely misinterpreted the heading and thought this was a software-defined SoundBlaster ISA card! Maybe I'm not the only one.

Hi, your ISA Blaster is one of the stories we cover on the next episode of This Week In Retro. Could we have permission to show some parts of your video please? We won't use the audio and you will of course be credited with a link.

Could you use a wifi version to emulate an ISA network card?

this is cool! ^O^

Amazing! I wish I had that understanding! I just drool over projects like this waiting them to be available!

cool project man! I like it! What aboute buld an ardiono on an isa card? For cpu fan controlling for ex?

Are you using PIO features? Use those. Others have been able to emulate video cards on an Apple II bus with use of PIO.

Be cool to use this concept for a ISA parasitic processor "ISA CPU BLASTER" to accelerate renders like the old commodore 64 accelerators.

This is fantastic! I wonder if it could be adapter to provide EMS memory - that would be incredibly useful!

Nice work, as always! However, won't it be limiting to have access to only the lowest 4kB or RAM (12 address bits)? If you are already putting the level shifters on the board, how much could it hurt to add an extra latch/shift register and bang it with one of the PIO state machines to get access to the full address space?

Do you need something similar to a debounce for the multiple clicks?

I have been looking to do something similar but with PCI and a regular Raspberry Pi. I figured I could have the Pi pretend to be a 3dfx Voodoo, and have the Pi's GPU do the rendering. But it turns out I'm nowhere near smart enough for something like that 😅

Can it be used as VGA ISA video card?

I read that RP Pico can be overclocked up to 400 MHz. Main problem is that onboard QSPI flash memory is specified to work with 133 MHz (but it often work with 300 MHz), but that bus can be divided accordingly to work stable witch 400 Mhz cpu core. There are some videos about it on Robin Grosset YT channel.

Your connection between the USB mini and the larger USB A could be the problem. The signal is a differential one and ideally the wires should be impedance matched. Try making the wires as small as possible. Perhaps twisted pair wrapped with a ground.

This would be a good FPGA project.

Wow, really cool project! I've thought about trying to use an FPGA for something like this. Would certainly eliminate any performance bottlenecks but maybe a steeper learning curve.

What are the identification codes on the integrated circuits he used?

Could it be that the multiple clicks are happening because Dirty Rat may not have anti-bounce correction?

why emulate a UART to get a serial mouse working? Why not set it up as a bus mouse?

Curiously, why did you opt for through hole resistors when all the other passives were SMD?

Hi I loved the concept of this and it has given me an idea, I have an issue with using Diag ROMs on a 5170, they only work with a CGA or MGA 8bit card, the CGA card I have is not working and finding an easy way to view output from CGA would be amazing... My thought was not even initially providing output to display but pushing the raw text output from the CGA card emulation to the serial connection! This may be a nice initial step to get some output? and add DVI out later... Do you think this is possible, or am I mad? would really value your thoughts :) Keep on Blasting :)

Did you try to utilize the PIO-cores of the Pi Pico improve the timing?

Hmm, I wonder how it would cope running at higher baud rates. I am curious as to whats causing the issues with the left and right click. TinyUSB is strange with some mice but that doesnt sound like the case here, probably some lag on the picos side with pumping in the signal if thats the case id imagine you'd get further with a shift register or do what I did and give the second core of the pico the job of sending the mouse data with core 0 getting the mouse data from tinyusb. It helped my project a lot with pumping out data consistently.

can this be used to emulate MT32 using Pico? or perhaps using Pi Zero W?

Interesting. I especially liked that you adapted CuteMouse so you can leave out the UART emulation. Do you know at what rate (hz) your pointer updates at max? I believe for serial it was around 40 hz under DOS. Some bus mice could update faster.

are there no ISA USB cards for sale then? where a USB mouse can simply be plugged in

did you look into supporting ps2 at all?

Are there similarities between PicoGUS and ISA Blaster?

is it your natural voice or prepared for this video?

It would be nice if we could get VGA out from it. Also, could ESP32 work for this purpose or it is all on RP PIO to make it work?

kermit what happens if you aint got an isa slot lol we need pci converter that makes it dos think its an isa slot work that out.

Now, make an ISA host using Pico as a CPU with a 386 emulator :)

Would be nice to have asynchronous access, having a dual port SRAM chip, one side on the ISA bus and one side on the Pi. This would solve your timing issues.

hmm i wonder if this could be expanded to make a VGA card for HDMI use on retro computers

Kermit the Frog does electronics.

Awesome idea - I love the project!👍 Also I like the background soundtrack that is fully audible from 2:30 until ~4:10. Can you tell me the title of the track and name of the artist ? Thanks - and keep up the great work!

You need some simple hardware between ISA bus and PICO I/O.

Wow..

Switch bounce I bet. I suspect it could be debounced in software, eh? Cool project.

are there no ISA USB cards for sale then? where a USB mouse can simply be plugged in. Just google it and you'll find it.

Regarding that multiple-clicks issue: Is your mouse in good enough condition? The actual button's switch in the mouse might be bouncing slower than the ISA Interrupts are handled (some milliseconds maybe?). But you can examine that with a simple MCU script that just counts all Mouse Status transfer instances and Serial.print() them out - sorry, coming from ArduinoLand here... 😁; plus I don't know what platform you program your Pico in... Maybe rinse the button switch with some Isopropyl Alcohol, Contact Cleaner or WD40 to clean the contact points.

you may have already done this (if so ignore me) but you could've probably solved the speed issue by using the pico's programmable I/O to handle the UART emulation and have the CPU just feed the mouse data to the programmable I/O

Can we emulate a sound card in such project? That would be very nice. It might require a better Pi hardware, but imagine being able to emulate those hard to find and now expensive cards

Почему не на ардуино, она же медленней, что она с мышкой не справится?

i wonder if some day the bigger ISA cards can be simulated in this way (probably with an SoC with more pins, or an FPGA). Pair this with the dISApointment project (ISA over TPM), and this could potentially open up more general compatibility with legacy computing on modern devices.

always wondered what happened to ernie from sesame street

is this your natural voice sir? i mean nothing negative but you sound a bit like kermit the frog. guess it ain't easy bein green.

Just one point regarding soldering, it's better to use a vise-like pcb holder with two sides fixation or just a heatproof flat surface to solder smds. Third hand, in this case, less helpful, especially when liquid flux is used

Loved the video, but why not a Patreon channel? I would love to contribute monthly few dollars, and I'm sure I'm not the only one

I love the minimalism, but the cost of that approach is the PIOs have to lose much of their potential. They're fast enough to drive multiplexing and demultiplexing, and still not need individual registers implementing the interface of the card on the bus, as long as they're free to switch between functionalities. With that in mind, I think it's appropriate to add some logic to the design while keeping with the software-driven approach. - Output registers e.g. 74*273 avoid stalling PIO or CPU on ISA timing, the data can be clocked in while the register is already enabled, and each flip-flop only ever needs to drive one output. - The data output enable can be triggered by ISA read signals, and CPU code writing out data can drive the dedicated pins ASAP (be it early, or up to the moment data is sampled). A chip or two of NANDs should be plenty for this purpose. - You can side-set an output from PIO for "selected" in your address decoder, primarily for the output enable, but also use this to set CHRDY automatically with one or two flip-flops. Wait states are not ideal, but better than a miss on the bus. - 8x 74*251 digital multiplexer chips effectively integrate address decoding for 64 lines. This gives access to data and address lines with 12 GPIOs, 8 of which can still drive multiplexed output registers. - A 1:n analog mux can pull down the IRQ of your choice, with the pico enabling the mux to trigger an interrupt, and an output register holding the selected IRQ. This is the same function as an open-collector decoder, but a 1:16 mux is more common than a 4:16 open-collector decoder. All that should free up pins, even if the card was expanded to 16-bit, leaving 8-9 to throw at fun features: - An SD card slot for storage would be sublime. - After that, you have an SPI, two UARTs and two I2Cs, set them free! Breaking out headers for each lets you do whatever: I2C RTC, Temp sensor, Bluetooth module, Second SD card, GPIO expander, etc.

Next: Implement a custom 8 bit CGA/EGA/VGA card with the Pico ;-)

Oh btw, if I'm able to help just get in contact, id be happy to pass on whatever i know..

Emulate a multicore 386

why do you sound like kermit the frog

Sounds like Junior Addleburg from home movies

Why does he sound like that??😅