MichelS

From the software side you're not bothered with this too much. Suzy provides two registers for reading (and writing) data from cart. Reading from one of the registers will make Suzy strobe CE0, reading from other one strobes CE1. This way only one of both lines can go low at a time, and Suzy takes care of timing. After reading the data, the cart address is automatically incremented due to this diode circuitry going into the clk-input of the counter. This way you read data sequentially for (up to) a complete "page" i.e. until the counter wraps around (depends on the cartridge internal wiring, if it uses 9, 10 or 11 bits of the counter). The page is the upper 8 bits of the cartridge address and it's set with the shifter. Mikey provides another set of registers (or register bits) to set the databit and the clock-input of the shifter. Clocking data into the shift register has to be done in software, so this is a bit of work to be done by the coder. But each time a bit is shiftet in, the counter is reset automatically. You can see this in the schematics as the clk-input of the shift register is wired to the rst-input of the counter. Edit: the programmer doesn't even have to care for the shifting - there's a function in rom for that which you can call if you're lazy.

As i understand it, the diodes basically form a wired "AND". The inverter input is pulled high by the resistor. Any of the two CE/-lines going low will pull the inverter's input low via the corresponding diode. I'm not an expert in electronics though...

I'd say no - or at least very hard to tell. The IPS seems to operate at ~60Hz. Would make some sense since it can have VGA-output, and VGA is usually ~60Hz, right?

Cannot edit my post anymore, but just realized there can't be tearing on original screen. Data rate and display rate always match. For replacement screens, it's a different story: The tearing cannot be avoided unless the panel was driven at the same refresh rate as the original screen. But then you'd get terrible flickering with the new displays since they are much faster than the old screen. The new displays are usually operated well above 50Hz for this flickering reason. If pixel data are coming at a slower rate from the lynx, you get a tearing effect since one "lynx frame" is displayed over several "display frames" (not necessarily a whole number). On the other hand, if pixel data are coming at a faster rate, you essentially have to throw away data. This must give artifacts if the images are moving...

Hi, i just tested this on an original screen Lynx I and a BV IPS equipped Lynx II: On original screen, scrolling is smooth for all refresh rates. There are artifacts for the two highest refresh rates though. @78.06Hz there's color artifacts - some colored pixels arranged vertically along some of the stripes. @78.70Hz there are some flickering columns, even when not scrolling. These columns are evenly spaced - it's clearly an artifact from the video DMA. Something seems to go wrong with video timing here. On BV-IPS these artifacts at the two highest rates are also present. Additionally there's visible screen tearing when scrolling, especially at low refresh rates below 50Hz. It's not too bad though. I'm sure the tearing is present on the original screen as well. It just goes unnoticed due to the slow screen, which visually mixes (i.e washes out) several frames even at low refresh rates.

Mine was delivered yesterday - virtually. According to DHL online tracking, the parcel was sucessfully delivered. When i came home from work, i only found a note in my postbox saying my parcel was deposited "at the usual place". I searched everywhere but it's just not there. At my postoffice they say they can't do much - but they tell the postman who's doing this tour...

Is it this? Handy Specification, page 34, last paragraph: Timer 7 ("clocked" by timer 5) reaches zero and triggers interrupt on next borrow. Since it's not reloaded, it stays at zero. Now, everytime counter 5 reaches zero and clocks timers 7, the interrupt is triggered again. Or did i misinterpret your find?

Karri changed the rom directory structure of his CC65 in May - see: https://forums.atariage.com/topic/336279-my-cc65-version-of-the-compiler-directory-structure-has-changed/

256kb ROM... why not 512? Looking forward to this!

Yeah right - actually, i was just curious since there are all those download links for old firmware versions on the page. Well, they're all academic links then... Thanks again for the new firmware and your time!

Hm... That means - if say, now i have v1.06. I downgrade firmware for some reason (if that works) and later i want to upgrade again. I cannot use a firmware i saved now (while on 1.06) for upgrading again. I'll have to use the QR code while on downgraded firmware to obtain a new firmware file for upgrade? My head is spinning. Guess i'll take the advice and just enjoy playing old games...

Yes - used the QR code that is shown on my Lynx. I updated to v1.06 yesterday. The page that is shown now says: Updating Your Cartridge You currently have the latest version of the firmware available for the Lynx Game Drive installed! There is nothing for you to do except enjoy playing old games. ... Below are the download links for 1.06, 1.04, ... down to 0.92. When downloading e.g. 1.06 now, i get a file that isn't the same as the .upd from yesterday (which i downloaded through the large button on the top of the page) - but the same as the .ovr from yesterday i.e. different content. Also - i saved the firmware.upd for 1.04 when i did the update from 1.03 to 1.04. Downloaded 1.04 now is different from the old one as well...

Just came home from work and had to try this... So i downloaded the 1.04 firmware again. Indeed, it saves as "firmware.upd"... ...But the file content is identical to the 1.04 "firmware.ovr" i downloaded yesterday (byte-compared in hexeditor) and the LynxGD doesn't accept it, i.e. it does nothing except displaying the QR code.

I see... so the .ovr files are not usable unless this upgrade/downgrade feature is activated or added to the LynxGD firmware.

Thanks for the update! I wonder: how are the .ovr files supposed to be used? Since old versions of the firmware are offered as .ovr for download, i guess they can also be used for downgrading/upgrading firmware? But how to install an .ovr file on a gamedrive?