SainT Posted July 8, 2014 Author Share Posted July 8, 2014 I'll give some thought to that, it may be possible to have two modes of operation. This will only cause problems with 1MB homebrew however, not all. The majority of homebrew demos and games will work, it's only the 1MB carts or carts with backup that will be an issue... Quote Link to comment Share on other sites More sharing options...
SainT Posted July 8, 2014 Author Share Posted July 8, 2014 What 1MB Lynx carts even exist? Quote Link to comment Share on other sites More sharing options...
+karri Posted July 8, 2014 Share Posted July 8, 2014 none Quote Link to comment Share on other sites More sharing options...
SainT Posted July 8, 2014 Author Share Posted July 8, 2014 Really? I must admit I haven't been able to find any, but I find it surprising there aren't any. I wonder why carts like Alpine games use 2x 256K banks with bank switching using AUDIN rather than just 512K straight. The only difference would be they use 2K blocks rather than 4K blocks. I'm not sure the advantage of this, mind you, as you could happily start reading data half way through a block with just the penalty of additional reads... Quote Link to comment Share on other sites More sharing options...
+karri Posted July 8, 2014 Share Posted July 8, 2014 Alpine Games was written using BLL and the guys behind it are the same as behing the Drive School stuff. I believe that two 256k chips were also cheaper than a 512k unit at the time. There was also problems in this approach as the chip select was different in Lynx I and Lynx II. Because of this the boot record and the directory had to be on both ROM's as you had no idea of the polarity of AUDIN at startup. Another reason why 1M carts do not exist is that 256k is very much memory. You need lots of graphics and sounds to fill it up. None of my entries could even fill 128k. The only reason why Solitaire was 256k is the semi-naked ladies dancing in the credits I believe they ate up half of the cart as the graphics was full screen animations. Quote Link to comment Share on other sites More sharing options...
TailChao Posted July 8, 2014 Share Posted July 8, 2014 As far as I know the only things above 512KB on the Lynx are Sage's slideshow tool and the current game I'm working on (both 2MB). There's some more reading on the subject here, but again the usage is a slideshow creator and a not-yet-finished game. So I don't think it matters for your cart. You can get away with 100% commercial library compatibility with 512KB SRAM, a little flash for bootup, and some magic ports attached to the /CART1, AUDIN, and DATA pins to interface with your microcontroller. Quote Link to comment Share on other sites More sharing options...
108 Stars Posted July 8, 2014 Share Posted July 8, 2014 I see it different than Karri. The low memory of Lynx games so far is a major issue imo, 256 kb is just tiny. It just puts in major constraints in the graphics and sound department. If homebrews aim to match the best of the GB an GG in variety and detail, there is no way around having 1 Megabyte/8 Megabit/1024 Kilobyte. I know the fun is first and foremost, but as a pixel artist I want to do visuals that really do the hardware justice. Fun games with limited visuals don't need the Lynx... the thing about th Lynx is that it can outperform its competitors from back in the day. To fully utilize its capabilities, we must not handicap ourselves by limiting memory below what GB and GG offered. Sticking with 512 kb is like tying up one hand behind our back. 2 Quote Link to comment Share on other sites More sharing options...
GadgetUK Posted July 9, 2014 Share Posted July 9, 2014 I think it doesn't really matter, but what would be nice is a method to page between 512Kb blocks (or 256Kb blocks) in someway - therefore allowing absolutely massive games. Almost a psuedo mapper to be used in new homebrew etc. Quote Link to comment Share on other sites More sharing options...
Gregory DG Posted July 9, 2014 Share Posted July 9, 2014 Finally! The Lynx is an awesome system, it's about time it had a flash-cart! BTW, my entire collection of Lynx ROMS is under 30 meg... Would have to fill a modern SD card with something else! (BTW, I didn't read the entire thread, but what physical style are you planning to use? Micro or the standard size?) Quote Link to comment Share on other sites More sharing options...
SainT Posted July 9, 2014 Author Share Posted July 9, 2014 (edited) On 7/9/2014 at 7:28 PM, GadgetUK said: I think it doesn't really matter, but what would be nice is a method to page between 512Kb blocks (or 256Kb blocks) in someway - therefore allowing absolutely massive games. Almost a psuedo mapper to be used in new homebrew etc. Yeah, I've already said the plan is to have the Lynx communicate with the microcontroller on the cart allowing you to load files from the memory card anywhere in the Lynx rom space whenever you like. So you could have 4gb (or more) Lynx games if you really wanted. Sampled audio tracks are the obvious use to me. Edited October 25, 2019 by SainT Quote Link to comment Share on other sites More sharing options...
SainT Posted July 9, 2014 Author Share Posted July 9, 2014 I've got it all straight in my head now, I've got a PIC chip selected, and I'm starting on the PCB layout for a prototype. I was going to do a bread boarded prototype initially, but whenever I've tried things like that in the past I've run into trouble, so I've decided to just get a PCB made and make my life easier. I've not done a massive amount of surface mount work before, so assembly should be interesting... some 0.65mm pitch soic's needed. Quote Link to comment Share on other sites More sharing options...
108 Stars Posted July 9, 2014 Share Posted July 9, 2014 Yeah, I've already said the plan is to have the Lynx communicate with the microcontroller on the cart allowing you to load files from the sd card anywhere in the Lynx rom space whenever you like. So you could have 4gb (or more) Lynx games if you really wanted. Sampled audio tracks are the obvious use to me. I don't mean to say that 1 MB in a single chip is necessary. My comment was just to say that 512 kb is quite limiting. If we can get moeit doesn't matter to me if would do it via bank sitching, multiple smaller ROM chips or cheap modern flash memory. I take it that however we will eventually get big games, the coders csn design them with the flashcard in mind and make them compatible. Quote Link to comment Share on other sites More sharing options...
Uzumaki Posted July 14, 2014 Share Posted July 14, 2014 Can Lynx support more RAM? Directly ot indirectly like other game carts (SARA for 2600 for example)?? How about an Aladdin Deck Enhancer-esque add on cart that can be used with future homebrews? Or add that into the multi-cart and have future homebrewn games use it? Quote Link to comment Share on other sites More sharing options...
SainT Posted July 14, 2014 Author Share Posted July 14, 2014 Nope, cant do anything interesting like that on the Lynx. The cartridge is purely a compact flash like device, it's not a direct bus interface, sadly. Quote Link to comment Share on other sites More sharing options...
108 Stars Posted July 14, 2014 Share Posted July 14, 2014 I prefer it that way. I think the Lynx has plenty of potential as it is, and with extra RAM it just wouldn't be the Lynx anymore imo. Quote Link to comment Share on other sites More sharing options...
SainT Posted July 15, 2014 Author Share Posted July 15, 2014 I guess I'm about 50% the way through the PCB layout for the prototype... 6 Quote Link to comment Share on other sites More sharing options...
walter_J64bit Posted July 16, 2014 Share Posted July 16, 2014 I guess I'm about 50% the way through the PCB layout for the prototype... Now that's a thing of beauty! Quote Link to comment Share on other sites More sharing options...
Greg2600 Posted July 16, 2014 Share Posted July 16, 2014 Aesthetic question, but will/can the PCB be printed in black/dark grey? Quote Link to comment Share on other sites More sharing options...
SainT Posted July 16, 2014 Author Share Posted July 16, 2014 I was planning on black PCB for production versions, yes. 1 Quote Link to comment Share on other sites More sharing options...
LX.NET Posted July 16, 2014 Share Posted July 16, 2014 I am impressed with the progress you are making. Keep up the pace. 1 Quote Link to comment Share on other sites More sharing options...
+karri Posted July 18, 2014 Share Posted July 18, 2014 I guess I'm about 50% the way through the PCB layout for the prototype... Are you creating the schematics while doing the routing? Quote Link to comment Share on other sites More sharing options...
SainT Posted July 20, 2014 Author Share Posted July 20, 2014 In this case the routing is leading the schematic as with SRAM you can connect the address and data lines as you like as long as you are consistent about how it's read and written on both sides. Because of this flexibility I've done the majority of the routing on just one side of the PCB, which is nice, as I find SMT stuff a bit of a pain to layout as you can't run traces between chip legs as you can with through hole. Will be interesting to see how long these take to put together. Might get myself a small reflow oven... Quote Link to comment Share on other sites More sharing options...
SainT Posted July 20, 2014 Author Share Posted July 20, 2014 I've been thinking more about the idea of also using this cart for development. I've come to the conclusion I can very simply (and at no extra cost!) add a TTL uart connector to the cart. You can connect this to the PC via a simple USB to TTL RS232 converter available on ebay for a couple of quid (search for 2303hx). 1 Quote Link to comment Share on other sites More sharing options...
Uzumaki Posted July 21, 2014 Share Posted July 21, 2014 Will be interesting to see how long these take to put together. Might get myself a small reflow oven... Check Goodwill for a cheap working toaster oven. People often use it as reflow oven. Just don't plan on using it for food afterward or your pizza might taste funny Quote Link to comment Share on other sites More sharing options...
Songbird Posted July 25, 2014 Share Posted July 25, 2014 Very cool project! Glad to see people still have an interest in designing cool hardware to work with this awesome handheld. I would agree with several others in this thread that compatibility with EEPROM saves on a handful of known cartridges (SIMIS, MegaPak, etc.) would be ideal. This would also cultivate a standard for future homebrewers to use, and would allow them to create a physical cart with a 93c86 on it, or use the multi-cart, and not have to make two versions of their game. Next project for you: a ComLynx to WiFi or Bluetooth adapter, so we can get rid of all those pesky cables... 1 Quote Link to comment Share on other sites More sharing options...
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