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Everything posted by JohnnyRockets
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Transfer directly to Stack?
JohnnyRockets replied to JohnnyRockets's topic in 2600 Programming For Newbies
Thank you Andrew, I will study this macro! JR -
Transfer directly to Stack?
JohnnyRockets replied to JohnnyRockets's topic in 2600 Programming For Newbies
Thanks Stephen! Now looking at this snippet: --------------------------- processor 6502 seg code org $F000 ; defines the code origin at $F000 Start: sei ; disables the interrupts cld ; disable the BCD decimal map mode ldx #$FF ; loads the X register with #$FF txs ; transfers X register to S(tack) register ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Clear the Zero Page region ($00 to $FF) ; Meaning the entire TIA register space and also RAM ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; lda #0 ; A = 0 ldx #$FF ; X = #$FF sta $FF ; make sure $FF is zeroed before the loop starts MemLoop: dex ; x-- sta $0,X ; store zero in A, at address $0 + X bne MemLoop ; loop until X==0 (z-flag set) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;Fill ROM size to exactly 4KB ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; org $FFFC .word Start ; reset vector at $FFFC (where program starts) .word Start ; interrupt vector at $FFFE (unused in VCS) --------------------------- Question: What values are now stored in $FFFC and $FFFE? And why? My guess is Zeros? Thanks! JR -
Hi all, In the following "newbie" code snippet: -------------- processor 6502 seg code org $F000 ; defines the code origin at $F000 Start: sei ; disables the interrupts cld ; disable the BCD decimal map mode ldx #$FF ; loads the X register with #$FF txs ; transfers X register to S(tack) register -------------------- Could we have just loaded #$FF directly into the Stack register, thus saving a step/instruction? Thank you, JR
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TheC64 Full Size - Pre-orders Open for USA
JohnnyRockets replied to StephenJ's topic in Commodore 8-bit Computers
$132.48 delivered Not even sure what retail even was... I just went with it cause I wanted one. Just curious, what is retail? JR -
TheC64 Full Size - Pre-orders Open for USA
JohnnyRockets replied to StephenJ's topic in Commodore 8-bit Computers
Hi all, I kind of did a "spur of the moment thing" last Sunday night... I wanted to see if any "64 Maxis" were available anywhere in the US. I found one on the "iWoot.us" website, a website that sells a bunch of crazy stuff that appears to be all over the map as far as topics go. They had only one 64 available, so I bought it thinking they'd cancel the order once they realized that they didn't really have any in stock. But lo and behold, it shipped and arrived today, only 3 days later (from the UK - it is the UK version)! Honestly, it blew my mind! It still kind of does! LOL! JR -
TheC64 Full Size - Pre-orders Open for USA
JohnnyRockets replied to StephenJ's topic in Commodore 8-bit Computers
Perfect, thank you for clarifying! JR -
TheC64 Full Size - Pre-orders Open for USA
JohnnyRockets replied to StephenJ's topic in Commodore 8-bit Computers
Hi all, Can you all tell me what the main differences are between the UK version and the US version? Thank you! JR -
Very interesting, I did not know that! AZERTY (makes sense!) Thanks, I'll check them out for sure. JR
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100% agree! We sound about the same age, and those were awesome times to play with computers and now there are SO many great emulators out there you get to "try before you buy" so many of them! On that note I shot you a PM with a specific Coco2 question. Thx! JR
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Hi Michael, I had the PC-1 growing up and thought it was pretty cool! Never did too much with it, but it still has a special place in my "retro" heart. Does this site provide any insight? https://www.floodgap.com/retrobits/tpm/138.html JR
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Hi Michael, I appreciate your thoughts greatly! The Coco 2 is very nice as well. I'm trying to grab a childhood "wished I had it" moment here and I specifically remember going to my local Radio Shack and "ooohing" and "ahhhing" over the Tandy Color Computers. I ended up with the VIC-20, cause that was what I could afford with my Christmas money when I was 13 years old. Now I can afford it ALL! But I want to limit the technology, so the Coco 2 I will definitely look very close at, and I am intrigued with Assembly Language and do enjoy playing with that as well. So we'll see how it all pans out.... 100% agree with the SDC controller idea, that is key if I make the jump from emulator to physical... And, oh man yes, the color computer archive is a GREAT site! Thanks again Michael, and just curious if you had the Coco growing up or are just getting into it now? JR
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Hi tsteege, That Alice seems kind of cool, but is it only French or English too?
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Atari researchers, $8 or $20 plan at newspapers.com?
JohnnyRockets replied to Random Terrain's topic in Atari General
Hi all, Just curious what you "find" in those newspapers? Atari ads and articles? Cool! JR -
Which 8bit micro you wish you tried bitd?
JohnnyRockets replied to phoenixdownita's topic in Classic Computing Discussion
Hi all, I have one other addition. The Tandy MC-10 or the Alice computer (RED is cool!). I've been playing with the MC-10 a bit lately and it's pretty fun (Emulation). I have owned one in the past, but it went "away" when we moved houses. I'm thinking about buying another one. JR -
Hi all, Just starting playing around with the MC-10 Color Computer. This is the one that I think I would have bought in addition to my VIC-20 way back in the day. I could have afforded it. Anyone play with one of these? I might try to buy one. Thanks! JR
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Which 8bit micro you wish you tried bitd?
JohnnyRockets replied to phoenixdownita's topic in Classic Computing Discussion
All I could think of was the Commodore PET. Man, if I could just have owned that one! Whew! $3000 was the price tag at that time and my Dad said, "I don't think so!". Settled for the VIC-20 later on with my allowance, but I still dream of learning more about how to program the "PET". I still may, but I just need to find a group or a forum or something that is really PET-centric, maybe on FB? JR -
Another resource for beginner Atari 2600 programmers.
JohnnyRockets replied to jas_new's topic in Atari 2600 Programming
I'm taking that course right now! LOVE IT! JR -
Hi all, I'd like to jump into programming for the Commodore PET. This is such an awesome forum for the Atari, can anyone recommend a good programming forum for the PET? Thank you! JR
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Looks VERY cool!
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Is a 6502 processor always a 6502 processor?
JohnnyRockets replied to JohnnyRockets's topic in Atari 2600 Programming
Wow, thanks guys, that REALLY helps me and gives real clarity for the future. I appreciate it! JR -
Hi all, I have a question regarding the "general" learning/programming of the 6502 processor. I am currently learning ASM programming for the Atari 2600 and as I am studying, I am learning the specifics of the 6502 processor registers, etc. (nothing new here) Once I have a general understanding of the 6502 ASM "in's and out's", will it then be "somewhat" (certainly different in many ways) manageable to then move to programming other 6502 based machines? I would like to branch out to some of my childhood favorites (Commodore PET and VIC-20) as well in the future. What are your thoughts please? (apologies if this is an improper place for this post) JR
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Now you got me interested in the Teensy board! JR
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From game creation to cartridge/box rollout - Steps?
JohnnyRockets replied to JohnnyRockets's topic in Atari 2600 Programming
Hi! Thanks! I did not know that AA would/could do it. That'd be my preference. Really appreciate it! JR