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The console detection is cool - I never expected it to work I'm not keen on the chunky PF text at the bottom - it is probably possible to do better using RESPx tricks. What are the constraints, i.e. how many digits do you need for the score & lives, and what is the width of the scanner? Chris

There are 2 versions of Star Castle on the 2600. Do you mean "Starcastle Arcade" in the Atariage store, or the earlier Kickstarter "Starcastle" by D. Scott Williamson? Chris

This suggests an issue with your joysticks - what kind are you using?

Does it keep scrolling if you unplug the joysticks?

Thanks Nathan - it doesn't need to be the worst case. I'd like to buy it from you though, as I'd need to do nasty things to the insides of the console! Chris

I would really like to get one of the Jrs that doesn't work with bus stuffing to do my own testing. I've bought 4 PAL Jrs now and they all work fine! If anyone would like to sell their non-working NTSC Jr (and doesn't mind shipping to the UK) - please let me know! Chris

They tried it before with the "apple bandai pippin" console - it didn't work out well ...

A beautiful pair of 3D printed cases from c0d3m4st4: Chris

I should add my consoles: PAL Jr - ok PAL Light4 - ok Chris

When writing 6502 code, you can often optimize out the CLC instructions as you can infer that the carry will not be set at that point in the code, e.g. you have already performed an addition that cannot overflow. Chris

If you want to add numbers that are longer than 8-bits it is very useful. A number larger than 8-bits is represented using multiple 8-bit values. To add them together, you clear the carry and start adding them together from the lowest pair. If the addition overflows, the carry-out becomes the carry-in for the next addition. The code below shows how to add two 16-bit numbers. Notice that there is no CLC after the first addition as the carry flag needs to be preserved: add16: clc ; clear carry lda num1lo adc num2lo ; add low numbers sta reslo ; store low sum lda num1hi adc num2hi ; add high numbers with carry sta reshi ; store high sum

Although the PF and MASK have 256 possible values each, it seems unlikely that you will need all possible combinations. If you could reduce the number of "building blocks" for your levels to 16 (e.g. by halving the horizontal resolution) then you could do the AND operation before the kernel (i.e precompute it) and pack 2 results into a byte as shown above. However, given that you are only performing this operation every 4 lines it does seem that you will not save all that many cycles. An extra 128bytes is still a long way from 64KB Chris

The mask operation during the kernel looks quite expensive - it appears you are doing something like this: lda (LEFTPTR),Y ; 5 and LEFTMASK,X ; 4 sta PF2 ; 3 = 12 I wonder if you could precompute the mask operations and store them in RAM. With a vertical resolution of 40, you would need 160 bytes, i.e. too much. But if you could find 16 patterns that covered all the needed PF values you could encode two positons in 1 byte, which would only need 80 bytes, i.e: ldx LEFT,Y ; 4 lda Left0,X ; 4 sta PF2 ; 3 lda Left1,X ; 4 sta PF1 ; 3 = 18 LEFT would contain the PF2 pattern in bits 0-3 and the PF1 pattern in bits 4-7. It would waste a bit of ROM as you would need to fill two pages of possible values for Left0 and Left1 but it would save a lot of cycles. What are your constraints? With an extra 128-bytes of Superchip (SARA) memory, the RAM wouldn't be an issue. And with DPC+ you could simply read the data out of a fast fetcher? Chris

Try the Atari 2600 joystick in the 7800 to see if it an issue with the controller or the console. Chris

There are two Star Castle homebrews. It is "Star Castle Arcade" by me and Thomas Jentzsch that doesn't work. The earlier "Star Castle" homebrew by D. Scott Williamson is the one that is working. Chris

Order a homebrew game and Al will send you one for free!

No problem - don't forget to check out my game on the portable too: http://atariage.com/forums/topic/125269-juno-first-final-version-atari-2600/page-17?do=findComment&comment=3659554

Here: http://atariage.com/forums/topic/259166-flashback-portable-needed-controller-hacks/page-5?do=findComment&comment=3667814

I'm looking forward to your review comparing the two versions of Starcastle!

Juno first doesn't use extra RAM - the chacksum may just be for games that need SARA ram? Chris

The no content thing happened to me once and it turned out I had accidentally clicked on the wrong settings in the pane on the left. Chris

I rechecked my modifications and it should still give you an extra ship at 10,000 - let me know if you encounter the problem again and I'll dig deeper. Chris

Try renaming it ALL CAPS, i.e: JUNO1.BIN Chris

Thanks - no donation necessary! Homebrew games tend to push the limits of the original hardware, so many will not work on the flashback as the emulator is quite basic. There is a very long thread discussing game compatibility here: https://atariage.com/forums/topic/258970-atari-flashback-portable-compatibility-list/?hl=%20flashback%20%20compatibility Chris

Thge folder should be named "Game" (with a capital G), not Games as previously indicated above. Are you able to see other .bin files on the SD card? Chris