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Messages - ralphdspam
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46
« on: February 08, 2012, 01:17:34 am »
Was I not updating the topic weekly? Whoops. 
Anyways, there is a very nice use of SCF in Axe's sound routine. Instead of using it for math, it is used for conditional branching. xor a
__FreqOutLoop1:
push bc
ld e,a
__FreqOutLoop2:
ld a,h
or l
jr z,__FreqOutDone
dec hl
dec bc
ld a,b
or c
jr nz,__FreqOutLoop2
ld a,e
xor %00000011
scf
__FreqOutDone:
pop bc
out ($00),a
ret nc
jr __FreqOutLoop1
47
« on: February 02, 2012, 10:32:35 pm »
Plus, Super Mario World is not a NES game. (Unless you're using some sort of rom hack of a NES game, but in that case it probably sucks anyway)
Unless he meant Super Mario Bros.
There is a Mario World clone for the NES. It's not great, but it does exist.
48
« on: February 02, 2012, 07:54:29 pm »
Yay! More Prizm games! 
49
« on: January 31, 2012, 10:06:17 pm »
I think the "Done" covering the text is the normal behavior and that the emulator you are using is incorrect. Regardless, I would add a res 5,(iy+0) to the beginning of the program which tells the OS to not display "Done" at the end. Also, I recommend WabbitEmu instead as it has more features and emulates more accurately.
Also on the topic of text display, some BCALLs, like DispHL, do not work in mathprint mode.
50
« on: January 29, 2012, 08:25:27 pm »
I should also point out that if you ever intend to consult others or ask questions, brandonW destroyed OS 2.41 and my workhorse is 2.53. Talking about different OS's can be a little challenging sometimes.
I'm going to disassemble OS 2.55. I want to take a look at the USB routines and the BASIC parser. Maybe I can fix that annoying mathprint screen glitch. EDIT: Hey, look at that! His site is back up.  EDIT2: It asks for the end of BCALL jump table. What should I put down for 2.55? I don't know because I haven't disassembled the OS yet. EDIT3: I entered the example numbers, hopefully that's right.
EDIT4: Ok, I somewhat figured out the paging. Edit > Segments > Create SegmentSegment Name = (Just note that if your name starts with a number, an underscore will be automatically added.) Start Address = IDA linear address End Address = IDA linear address + 1 (If you want your page to end at 0x4FFFF, use 0x50000) Base = (StartAddress - VirtualAddress) / 0x10 Example: Segment Name: Page02 Start Address: 8000 End Address: C000 Base: 400
51
« on: January 29, 2012, 06:19:09 pm »
Thanks. I saw something about using paging on 8086 code, but it seems that the method depends on the Segment Register. (AAAHH! ) (If you happen to be disassembling 2.53 or 2.55 and you are on a x64 machine, I can give you my current progress (I'm pretty sure this is actually legal too ))
Thanks for the offer, but I think I'll learn the most if I disassemble it myself. Unfortunately, brandonw.net seems to be down right now. I'll download that tool as soon as it goes back online.
52
« on: January 29, 2012, 05:11:00 pm »
So far, I have been able to produce tones over the IO port by toggling bit 4/5 of port B (7720 specs). Does anyone know how the Prizm's OS does it? I have tried the DAC hardware, but it isn't present, as well as the SIOF hardware, but wasn't responding. I can replicate what the prizm OS puts out from using Send(, but it doesn't seem right. I have been analyzing the output waves, but again, it looks like the OS has a tad more control. For example, writing to that port only outputs adds/subtracts voltage from the port. I don't know how best to explain, other than:H - reset, add
L - set, subtract
... - wait, equal time
() - level from -1.0 ... 1.0
(0) ... (0) ... H ... (1.0) ... (0.9) ... (0.75) ... L ... (-.25) ... (-.22) ... (-.20) ... H ... (.8) ... (.65) ... (.55) ... L ... (.45)
I could get in an image of my recording of it, but the above shows that it discharges inversely to 0 and writing to the ports doesn't set it, it just offsets it. When looking at the OS's IO output, it seems like it has analog control over it. It can keep the signal low or at an exact position, for ex.. If I am not making sense, :-S Fill me in on terminology :-)
Analog control? That would be awesome for sound projects! Which of the pins does this control? Can we control other pins in the same manner?
53
« on: January 29, 2012, 05:03:12 pm »
Is there an easy way to emulate ROM paging in IDA, or do I have to disassemble each page separately?
54
« on: January 22, 2012, 05:37:14 pm »
56
« on: January 21, 2012, 05:02:01 pm »
Cool!
I wonder if you can plug it into USB and draw the 5V from that...
Do you mean like from the USB port on your calc?
Yeah, if you plug it into the computer and draw the five volts from the calc's USB port.
57
« on: January 21, 2012, 02:54:04 pm »
Cool!
I wonder if you can plug it into USB and draw the 5V from that...
58
« on: January 16, 2012, 03:21:52 pm »
Yes! More games on the Prizm!
59
« on: January 14, 2012, 07:19:46 pm »
Wow... That's insane!
60
« on: January 13, 2012, 07:55:38 pm »
Nice code, but I can't think of any other uses of the command. Can you think of any hacky type usage?
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