Why is the 40/80 col. display manager slowing the VIC?

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groepaz
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by groepaz »

I guess you never have tried a basic game.
enough to consider basic not suitable for games and avoid them at any cost =)
If you think it's a bad test, then just go and make your own.
i did one that measures instruction timing :) as for basic... oh well. its slow and slower. no need to test that for me =P
find it a bit strange that the C128 manages to slow down even the text output that much.
it does bank switching for each and every character (each call of CHROUT)

edit: here ... its for c64 though and probably doesnt make a lot of sense to port it to other cbm machines unless you want to compare against some accelerator (other than that it will not really give you useful numbers, assuming you know the CPU speed already :=))
Last edited by groepaz on Mon Dec 02, 2013 12:02 pm, edited 2 times in total.
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Kweepa
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by Kweepa »

groepaz wrote:
I guess you never have tried a basic game.
enough to consider basic not suitable for games and avoid them at any cost =)
HERETIC!
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Jeff-20
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by Jeff-20 »

groepaz wrote:
I guess you never have tried a basic game.
enough to consider basic not suitable for games and avoid them at any cost =)
Ouch.
High Scores, Links, and Jeff's Basic Games page.
Boray
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by Boray »

groepaz wrote: enough to consider basic not suitable for games and avoid them at any cost =)
I suspect you came to this conclusion on something other than the Vic-20 (a C64 for example) and certainly not from trying out any of the games made by Denial members haha
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eslapion
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by eslapion »

groepaz wrote:
I guess you never have tried a basic game.
enough to consider basic not suitable for games and avoid them at any cost =)
If you think it's a bad test, then just go and make your own.
i did one that measures instruction timing :) as for basic... oh well. its slow and slower. no need to test that for me =P
:lol: ROFL :lol:

You're so better than everyone else!
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groepaz
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by groepaz »

You're so better than everyone else!
and you are a canadian with a stigma? deal with it.
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pallas
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by pallas »

groepaz wrote:
You're so better than everyone else!
and you are a canadian with a stigma? deal with it.
Let's not turn denial into (a) lemon.

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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by Boray »

Pallas in absolutely right. Keep it cool.
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eslapion
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by eslapion »

pallas wrote:Let's not turn denial into (a) lemon.
Well said. The subject of this thread was the difference in performance of the VIC with or without a hardware display adapter, not about bitching against basic or against canadians.

I feel Groepaz's posts were simply off topic and demeaning.
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by groepaz »

eslapion wrote:I feel Groepaz's posts were simply off topic and demeaning.
the one who apparently felt the need to post offtopic babble and a personal attack was you, not me. i just expressed my opinion regarding the possible useful application of a certain programming language - no more no less. note that this opinion my be different to yours - and thats fine.
i have absolutely no idea how you come to the conclusion that my intend was to express that i am "better than everyone else" (although that is true of course - but it has no relevance here :o))

Boray: to come back to the topic - i came to that conclusion after many years of programming on different commodore computers (from PET to VIC20, admittedly C64 is my main box). i have written my share of basic programs on all of these, mostly little tools but also some simple games (the breakout and tetris kind of things everyone does at some point) - and i always found it *way* too limiting whenever something that required a bit of speed comes into play. i am not saying basic is completely unuseable for games (games like PIRATES! are good counterexamples for that) - just that its strength isnt speed or fast i/o. the one strength of basic is that it produces very compact code, and it trades speed for that.
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by Boray »

I started programming on a Vic-20. I made a bunch of games in basic. Then I bought a C64 and continued programming there and my games all the sudden became much worse, almost not playable. There are a number of reasons why the Vic-20 is more suited for this (which I've posted about a couple of times before). But to be fair, my very best games includes some ML as well.
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eslapion
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by eslapion »

groepaz wrote:the one who apparently felt the need to post offtopic babble and a personal attack was you, not me. i just expressed my opinion regarding the possible useful application of a certain programming language - no more no less.
I started this thread by asking a very specific question about the performance of a specific piece of hardware that provides 40 or 80 columns display to a VIC-20.

You answered by assuming that this piece of equipment did its job in software and/or did not have its memory mapped, both of which are false and would have made the original question quite pointless.

Then you more or less turned the thread into a discussion on the relevance of using basic as a language to program games. That has nothing to do with the original question.
note that this opinion my be different to yours - and thats fine.
I never stated my opinion on this subject as this has nothing to do with the original post.
i have absolutely no idea how you come to the conclusion that my intend was to express that i am "better than everyone else" (although that is true of course - but it has no relevance here :o))
Thank you for belittleing everyone...
Boray: to come back to the topic - i came to that conclusion after many years of programming on different commodore computers (from PET to VIC20, admittedly C64 is my main box). i have written my share of basic programs on all of these, mostly little tools but also some simple games (the breakout and tetris kind of things everyone does at some point) - and i always found it *way* too limiting whenever something that required a bit of speed comes into play. i am not saying basic is completely unuseable for games (games like PIRATES! are good counterexamples for that) - just that its strength isnt speed or fast i/o. the one strength of basic is that it produces very compact code, and it trades speed for that.
What exactly do this "coming back to the topic" have to do with the Protecto 80 / Data 20 80 columns display adapter?

That was the real topic to begin with, may I remind you.
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groepaz
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by groepaz »

eslapion wrote:Thank you for belittleing everyone...
so far i have no reason to belittle anyone except those who are unable to get obvious jokes.
eslapion wrote:What exactly do this "coming back to the topic" have to do with the Protecto 80 / Data 20 80 columns display adapter? That was the real topic to begin with, may I remind you.
every time the topic shifts unexpectedly, make sure to call the topic police.
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6502dude
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by 6502dude »

I believe the slowness is being caused by extra CPU cycles being needed to write to 6545 display memory
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eslapion
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Re: Why is the 40/80 col. display manager slowing the VIC?

Post by eslapion »

groepaz wrote:so far i have no reason to belittle anyone except those who are unable to get obvious jokes.
One of the characteristics of high functioning autism is to be unable to understand many obvious jokes or expressions which were not previously explained so I take it you feel it is ok for you or anyone else to belittle autistic people...

At least you're consistent with your past communication habits.
6502dude wrote:I believe the slowness is being caused by extra CPU cycles being needed to write to 6545 display memory
I have a difficult time with that. The 6845 memory (yes, the Data20 display manager uses a 6845, not a 6545) is mapped somewhere in the BLK5 area and has exactly the same access speed as any other RAM in the VIC-20.

As stated before, in 40 col. mode, the display manager actually has less data to shuffle around than a C64 since it has no color memory and the CPU doesn't get any cycles taken from a video chip. Also, the VIC-20's 6502 doesn't support wait states that could come from some slower ram. It cannot be placed on hold by an external device, something the C64 does support through DMA.

The only possible answer so far: the firmware

The ROM for the ML code on the display manager is only 2k x 8 and, I'm sure our friend Groepaz will confirm this, very often, small ML code can be slower than larger one to perform the same job.
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