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Bgnome:
--- Quote from: Tiger-Heli on August 14, 2004, 09:00:09 am ---
--- Quote from: Bgnome on August 12, 2004, 05:23:33 pm ---i would be interested in seeing an updated review.
i just got the Two-bit encoder and soldered a ps/2 splitter for it last night. i am now waiting on my joysticks/buttons so i can test it out on a temp cp..
if you need more info on it, i posted a fairly informative email about it in another thread and am willing to post whatever other info i have, (pictures, key map, etc.).
--- End quote ---
Yep, I'd like the info. Also, I was curious whether the grounds are common on it (There are two grounds on each of the eight 10-pin Molex connectors). Are the grounds on Connector 1 common with the grounds on Connector 8?
Having said the above, I would prefer to concentrate the updates more on the minipac, I-PAC VE, and KeyWiz Max 1.5, as the two-bit encoder is about 40 units, NOS from the early 80's and only available on E-bay for probably the next six months, while the others are current production models.
--- End quote ---
i posted the keymap here:
http://www.arcadecontrols.org/yabbse/index.php?board=1;action=display;threadid=22871;start=msg188768#msg188768
original email about how it works:
http://www.arcadecontrols.org/yabbse/index.php?board=1;action=display;threadid=22851;start=msg186817#msg186817
pins 1 and 10 are common ground and connected to eachother on each bank, so you really only need to hook up 1 ground wire. my best guess is that there are still over 60 left, but it is in short supply. also, judging by the keymap, A, E, F, and G are repeated so that in essence only gives you 60 independent inputs. i havent gotten my buttons in yet so i havent been able to do any thorough testing but i did manage to get at least 36 keys pressed using strips of aluminum foil and my fingers. at the moment, i am soldering wires to it and will be mounting it into a plastic vhs box from blockbuster, (barely fits), along with barrier strips.
one thing i will note, but i dont know if it is just my setup. i am using it with a laptop which has only 1 usb input and 1 ps/2 input. i soldered a ps/2 splitter together according to a schematic i found online which lets me use a mouse and kb at the same time. i have a usb kb plugged in the usb slot. my splitter works but my encoder board seems to stop working sometimes. i have been testing the board by pressing the f1 button that is directly on it. i am fairly certain the soldering job is ok. but my trackball unit does have 3 superbright red leds in it so im wondering if its just an issue of limited power supply..
patrickl:
--- Quote from: Tiger-Heli on August 14, 2004, 08:53:04 am ---
--- Quote from: patrickl on August 12, 2004, 02:56:46 pm ---Heh, I see you still believe the performance of PS/2 is better ::)
Really, someone should clock that sometime to get this out of the way. I'd put my money on USB (since the bandwith is vastly superior and a few interrrupts are not gonna kill that lead) On the other hand, who cares. With games running at 60Hz (max) the computer has ages to wait on your keypresses. Still, it would be nice to know.
Nice overview though. You sure take a lot of time to research all these things. very impressive work.
--- End quote ---
Man, oh man, I leave my computer for a day and look what happens . . . :P
Okay, this has been discussed before, and I don't want to belabor the point or fan the flame war. . .
PatrickL: I found it interesting that in the post I am replying to you said "Really, someone should clock that sometime to get this out of the way." Then when RandyT asks you to test it you post "Maybe if you tell me what would it prove I would be interested. Right now I just don't see the point. I wasted enough time on this already."
Obviously it's important to you or you wouldn't harp on it so much.
--- End quote ---
I care about the performance USB vs PS/2 (in the sense of timing). I have no idea what Randy's test would prove and he won't explain either. I don't feel like taking my CP apart just to do some useless test.
In fact I feel rather ashamed I responded to his weird posts. I can't say I saw a on-topic argument in any of them. I'll just remove my replies, do the silly test and summarize the whole thing. Sorry for cluttering up your thread. I do realy like your site, but I also think you should rethink the USB vs PS/2 issue (even if it really is a non issue).
BTW I'm not arguing compatibility issues or specific scenario's where either USB or PS/ are preferred. I'm saying USB vs PS/2 performance is either a non-issue and maybe even it has a winner for USB.
patrickl:
OK, sorry for the delay, but I just can't seem to find my USB cable. The workshop has been cleaned up by the missus and now I can't find the cable.
I'll just recap my (deleted) posts:
Comparing PS/2 vs USB; performance issues:
- USB will suffer in response time because it's lower in priority, needs more handling in BIOS and OS and it shares the bus with other devices. Only other interrupts can effect bus delays though, so USB harddisks and printers etc (if people would even have those connected to their cab) are of no influence. I'm hard pressed to see the whole extra overhead caused by these issues lasting longer than 1ms. For instance the max interrupt can be 40 bytes on a 1.5Mbps connection (i.e. something like a .3ms delay)
- According to PS/2 protocol, each key press takes 1.1ms to be transmitted and a key release takes 2.2ms (PS/2 rated by design at 10kbps and 11bit's used per byte transmitted) At a frame rate of 60Hz there are 17ms per frame. Now imagine 4 players moving sticks and pressing buttons franticly. So with PS/2 you could release at max 8 keys within a frame before you actually start suffering more than a whole frame delay due to transmission speeds. Even with fewer keys pressed (for instance during one player games) it's easy to see these delays will have a similar (if not worse) impact on response times compared to the USB delays mentioned above.
- A large number of keys pressed/released is not so much a cause for delay with a USB encoder since the transmission is so much faster.
- The fixed limitation on the maximum number of 6 keys pressed simultaneously only exists in standard keyboard encoders. An encoder like the I-PAC (in USB mode) will have a limit on something like 14 to 22 keys simultaneously.
There are a few situations where circumstances basically force you to use either PS/2 or USB:
- If you have a pre USB computer or use an OS without (mature) USB support you go for PS/2
- If for instance you use a Mac, you are building a rotating control panel (where you will need to have only one "flexible" wire coming from the CP) or you have one of the newer PC's without PS/2 ports then you go for USB
I might add some considerations:
- For 4 player fighter cabs, performance issues with PS/2 might be a consideration, USB functions better here.
- If you think you are goinf to be in situations where something like 14 to 22 keys are pressed simultaneously, an USB I-PAC will not work. Although if you are in that situation PS/2 will suffer severly from performance issues too. You would actually need to find a completely different alternative or live with of the problems in either USb or PS/2.
- Futureproofing; If you keep in mind the time frame you will be using your cab for then it's wise to consider that USB seems to be pushing out PS/2 slowly but surely. Legacy free PC's have been coming out already and so you might end up with one as a replacement in the future. Maybe not tomorrow but what about in 5 or 10 years when your current PC breaks down? Remember how quickly the old big AT keyboard connectors went out the door after the new ATX motherboards were introduced.
So basically if there is no pressing reason to force you on either PS/2 or USB, it simply doesn't matter which you choose. Both will work fine and other factors should decide which encoder to pick. In hindsight I'm very glad my controller has both PS/2 and USB.
monkeybomb:
Let me start by saying I do not understand the deep technical side of any of this. So, I don't quite get why this is so heated.
I am a keyboard encoder customer and user. I play fighting games and sometimes I press 2 directions, three buttons and a friend could be doing the same. that's 10 buttons at a time. I use a ps/2 connection (keywiz) and have NEVER had ANY issues with it. Why would I use a up a USB port that I could use for something else, only to leave a ps/2 port unused. I also see a ps/2 connection on every MOBO at Fry's. So what is all that talk about?
I do NOT want to contribute to flames, I'm just interested in why this debate exists. And does the debate move beyond the technical realm? Does it have true practical common usage value?
Thanks for reading
patrickl:
--- Quote from: monkeybomb on August 14, 2004, 04:37:02 pm ---I do NOT want to contribute to flames, I'm just interested in why this debate exists. And does the debate move beyond the technical realm? Does it have true practical common usage value?
--- End quote ---
That's just the point I'm trying to make. You normally won't even notice the difference between USB and PS/2. What I object to is claims that USB cannot be used (especially since there is no real proof to back them).
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