+karri Posted February 19 Author Share Posted February 19 I also tried to load the games with SC RAM and they all fail. It appears that 16k games end up as 8k binaries by the dumper. Currently I use mainly my real Atari 7800 for all my tests. Quote Link to comment Share on other sites More sharing options...
+karri Posted February 19 Author Share Posted February 19 There is some good news and some bad news about the Pico when running modern homebrews. Here is the good news Complex games like 1942 works on the 2600+. If they are up to 128k. VID_20240219_085834.mp4 1942 (Concerto - Small ROM Build) (Single Background) (No Music) (20221011).uf2 So these were the Good News. ------------- Then the bad news... On a real Atari 7800 the situation is worse. The game boots but the screen has glitches. The sound works. But after a while... the game crashes. My gut feeling is that the Pico just gets too hot and the CPU throttles or something. So I would need a heat sink on the chip and a fan. That pretty much makes Pico unusable on the real consoles for complex games... ------------------------ So what next... As the Pico works nicely with the 2600+ I tried to use the flash for getting larger games to work. But the dumper really needs high speed RAM for reliable downloads. So the next step is probably to use all the RAM available for the dumping process and place a PIO/DMA process in the background to manage traffic between the flash and the RAM. This sounds very silly as I will break the compatibility with the real consoles. But the big games do not have enough RAM for the real consoles anyway so dedicated 2600+ images are the way to go for the games that are too big for Pico. 4 2 Quote Link to comment Share on other sites More sharing options...
Ben from Plaion Posted February 19 Share Posted February 19 15 hours ago, karri said: VID_20240219_085834.mp4 73.68 MB · 0 downloads This looks so good in motion. Brought some memories back as a kid playing on arcades. Real nice to see. 1 Quote Link to comment Share on other sites More sharing options...
MarcinJ Posted February 20 Share Posted February 20 10 hours ago, Ben from Plaion said: This looks so good in motion. Brought some memories back as a kid playing on arcades. Real nice to see. @Ben from Plaion it would be fantastic to be able to get it as a cartridge for 2600+ 5 Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted February 28 Share Posted February 28 For the 7800 rom files, can .A78 format be used or does it have to be bin? Quote Link to comment Share on other sites More sharing options...
+karri Posted February 28 Author Share Posted February 28 You can convert a78 or bin files to uf2. For a78 files the script gets the information from the header how to emulate the cart. For bin you need to find out the details by yourself Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted February 28 Share Posted February 28 27 minutes ago, karri said: You can convert a78 or bin files to uf2. For a78 files the script gets the information from the header how to emulate the cart. For bin you need to find out the details by yourself Thanks, a78 works best for me. Quote Link to comment Share on other sites More sharing options...
Spanner Posted March 12 Share Posted March 12 (edited) Just found this on Facebook, its very similar... but its for the A800, its in the Atari 8-bit Computers Group. You could call this A2600PicoCart.. https://www.facebook.com/groups/181644898539691/?hoisted_section_header_type=recently_seen&multi_permalinks=7214389891931788 Edited March 12 by Spanner 1 Quote Link to comment Share on other sites More sharing options...
+karri Posted March 12 Author Share Posted March 12 Pico is a nice tool for emulating carts. Unfortunately it cannot compete with a real fpga implementation. Quote Link to comment Share on other sites More sharing options...
Spanner Posted March 12 Share Posted March 12 (edited) 1 hour ago, karri said: Pico is a nice tool for emulating carts. Unfortunately it cannot compete with a real fpga implementation. Couldn't you use the Raspberry PI3 A for this, its used on PiStorm because its thinner so would maybe fit nicely inside a A2600 cartridge case, its as big as the RPI3 so as big as a credit card but thinner then the RPI3 B+. It a little bit shorter then the RPI3 B+ too because it has no RJ45 connector for a network connection. Edited March 12 by Spanner Quote Link to comment Share on other sites More sharing options...
astroguy Posted March 12 Share Posted March 12 Development for the Pico is relatively easy, very cheap ($5) and light on power. It's a microcontroller, so bit-banging on GPIO is straight forward. Development for the Raspberry-Pi is more complicated, more expensive and more power-hungry. You have to worry about system interrupts for your timing. I'm not saying it can't be done, it's just more difficult and not the best use of a Raspberry Pi. We are implementing a ROM so the board needs to respond to the CPU when the CPU expects to see a signal on the data-lines. If system resources go towards responding to disk I/O, network, etc., then you could easily miss a data-transfer. FPGA and microcontrollers work well for the ROM task, with FPGA being the superior choice but more expensive and harder to develop for. With a Pico you can develop in C/C++ and easily debug problems with a serial interface. FPGA's use hardware design languages and the development process requires a lot of simulation and testing to get the hardware implemented. Good news is that the price of FPGA's is slowly coming down and the performance of microcontrollers (number of GPIO and clock) is going up. Quote Link to comment Share on other sites More sharing options...
+karri Posted March 13 Author Share Posted March 13 The Pico overclocked to 400MHz can still not react fast enough to some bankswitch modes. The chip is already too hot and would require active cooling. A better alternative is to use a real memory chip for simulating a rom. Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted March 13 Share Posted March 13 How important is the spec of the PICO board in that tthe fimware works with it? (Ram, memory etc). The board below (from Alliexpress) is used on the A8PICO cart and i haven't had an issue in quality. Would the one below also work with the 2600+ card project build? Quote Link to comment Share on other sites More sharing options...
+karri Posted March 13 Author Share Posted March 13 5 minutes ago, Magic Knight said: How important is the spec of the PICO board in that tthe fimware works with it? (Ram, memory etc). The board below (from Alliexpress) is used on the A8PICO cart and i haven't had an issue in quality. Would the one below also work with the 2600+ card project build? The critical part is the amount of RAM. The flash is too slow for being run at 400MHz. Many homebrews won't fit in the 256k of RAM available. Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted March 13 Share Posted March 13 1 hour ago, karri said: The critical part is the amount of RAM. The flash is too slow for being run at 400MHz. Many homebrews won't fit in the 256k of RAM available. Thanks, Ill heed advice and stick to the SC0915 type as recommended earlier in the posts, https://www.mouser.co.uk/ProductDetail/358-SC0915 Quote Link to comment Share on other sites More sharing options...
+karri Posted March 13 Author Share Posted March 13 33 minutes ago, Magic Knight said: Thanks, Ill heed advice and stick to the SC0915 type as recommended earlier in the posts, https://www.mouser.co.uk/ProductDetail/358-SC0915 The cart is great for running some homebrews and most 2600 titles. For many titles you need an external powerbank. Some high speed titles makes the pico run very hot. The games may crash... Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted March 13 Share Posted March 13 33 minutes ago, karri said: The cart is great for running some homebrews and most 2600 titles. For many titles you need an external powerbank. Some high speed titles makes the pico run very hot. The games may crash... Thanks, i mainly game with 7800 stock titles, but good info to know for the higher end titles done more recently with the extra weight, Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted March 13 Share Posted March 13 Im currently building this up and have noticed there is a difference on pcb revision from the pictures on the github and previous posts. Could someone kindly let me know what resistor value R3 is on this build? (Its from the VBUS leg to the capacitor) Quote Link to comment Share on other sites More sharing options...
+karri Posted March 13 Author Share Posted March 13 57 minutes ago, Magic Knight said: Im currently building this up and have noticed there is a difference on pcb revision from the pictures on the github and previous posts. Could someone kindly let me know what resistor value R3 is on this build? (Its from the VBUS leg to the capacitor) You will not be able to run any 7800 games on that cart. It lacks the 7800 signals. The resistor is likely 10k pullup for the switch. Quote Link to comment Share on other sites More sharing options...
astroguy Posted March 13 Share Posted March 13 58 minutes ago, Magic Knight said: Im currently building this up and have noticed there is a difference on pcb revision from the pictures on the github and previous posts. Could someone kindly let me know what resistor value R3 is on this build? (Its from the VBUS leg to the capacitor) It's a current limiter for a led (above S1). You don't need to populate it or the led at the moment. It's there for when I have a case to show that the Pico has power. Quote Link to comment Share on other sites More sharing options...
astroguy Posted March 13 Share Posted March 13 I've attached the PCB design to help. Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted March 13 Share Posted March 13 Thanks for the info guys, I'll focus on 2600 titles for this PCB and look at the other for 7800. I was thinking of a DC delay circuit for the over-quick startup inside a real 7800 to let the Pico catch up, if i implement this, ill share when tested. Great support here and I thank you all for this! Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted March 13 Share Posted March 13 1 hour ago, karri said: You will not be able to run any 7800 games on that cart. It lacks the 7800 signals. The resistor is likely 10k pullup for the switch. Are there gerber folder/files availalble for this?, I didnt spot them on Github Quote Link to comment Share on other sites More sharing options...
+karri Posted March 13 Author Share Posted March 13 8 minutes ago, Magic Knight said: Are there gerber folder/files availalble for this?, I didnt spot them on Github The whole pcb in KiCad format is there. You can plot the gerbers if you want. Or get pcb's from me. Quote Link to comment Share on other sites More sharing options...
Magic Knight Posted March 13 Share Posted March 13 1 hour ago, karri said: The whole pcb in KiCad format is there. You can plot the gerbers if you want. Or get pcb's from me. Thanks 😃 Quote Link to comment Share on other sites More sharing options...
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