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Member Since 29 Sep 2005
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#3089779 CartDump (Jindrich)?

Posted by Rybags on Sat Oct 11, 2014 5:40 AM

The other issue I should mention.  Cart copy programs that require hotswap and were written for 400/800 might fail on XL.  The OS keeps a constant watch on if the cart status has changed and will lockup or coldstart if it does.  Disabling Stage 2 VBlank will stop it doing so.

#3088716 Wanted: Assembler Editor Examples

Posted by Rybags on Thu Oct 9, 2014 3:47 PM

You're all wrong!


It's the construction worker from Village People, working hard on the lyrics for YMCA.





#3084802 Beach Head: C64 vs. Atari

Posted by Rybags on Fri Oct 3, 2014 8:15 AM

The speech could be added with a bit of work.  Would probably turn both into 64K games at the least but do the system justice by making the game as it should have been.

#3084500 VBXE -- what do you use it for?

Posted by Rybags on Thu Oct 2, 2014 7:04 PM

VGA Core requires modification of VBXE and you lose capabilities, from memory:


- 14 MHz crystal, VGA can be done but graphics are legacy only.

- 28 MHz crystal, VGA mode with reduced VBXE capability, only first 2 palettes of 4 available.


Scart RGB is pretty rare on TVs outside Europe and even dwindling there since Component is virtually as good but incompatible.

I have VGA input for my LCD TV like many but no idea if it would work with a 15 Khz composite sync signal.

#3082499 Good 16bit computer to start out with?

Posted by Rybags on Mon Sep 29, 2014 11:53 PM

First up, get the definition right.  TI isn't any more 16-bit than Jaguar was 64-bit.  Using the bus width of one subsystem to put a plaform among company it doesn't rightly belong with is all that is doing.


At the low end for gaming and the like, you can't go past Amiga 500 or 600.  600 has the advantage that you can more easily interface CF and HDDs to it internally or at minimal expense.

If you shop around, under $50 is achievable but don't expect too many extras with it.


I've got both Amiga and ST.  If you don't mind spending more money then a Falcon would be great but good luck finding anything much under $300 - when you consider what the machine can actually do you are paying much more for rarity and collector value than material/capability value.

#3079924 VBXE -- what do you use it for?

Posted by Rybags on Fri Sep 26, 2014 3:46 AM

But RGB video quality vs stock makes for much more readable and tolerable 4-pix wide characters in that mode.


One thing not mentioned and probably not utilized a great deal to date - you can in effect run dual displays with legacy video on one monitor, VBXE video on the other.  This could make for a great debugging setup or possibly a multitasking environment with VBXE showing tasks/status.


Note of course these things mentioned don't actually exist but the possibilities are there.

#3079757 16-bit divide by 8

Posted by Rybags on Thu Sep 25, 2014 7:16 PM

Dealing with graphics, probably the only improvement you'd get is if it's a repeating process - only do lookup on the first go, then bump the pointers, masks etc. around for subsequent iterations.


I thought of using a similar process to improve the line-draw algorithm.  It seems weird that so much effort has been put into optimising the calculation phase and improving by doing the start at the ends, meet in the middle method but the thing missing is improve the actual plot point by just shuffling the address/mask/data around rather than recalculating it every time.

#3078651 Atari DOS Directory BASIC One-Liner

Posted by Rybags on Tue Sep 23, 2014 10:11 PM

Directory can be had various one-line ways, I used to just go:

O. #1,6,0,"D:*.*":F.A=1TO9999:GET#1,D:PUT#16,D:N.A

You get a listing then Error 136 at the end.  If necessary, enter CL. #1 to close off the file (doing END or RUN will accomplish the same).


Much of what's otherwise in DOS command line or menu is just CIO special commands which Basic can do with XIO - so yes, stuff like Lock/Unlock file, Delete file can be done as one-liner as well.


In theory you could even create batch type files that work with Dos 2.x


The ENTER <filespec> command normally processes a Listed program file but you could create immediate mode commands as well.


So, e.g. you could ENTER "D:LOCK" - then have a one-liner in the file "LOCK" that DIMs a string then asks for the filespec to do the Lock command on, then execute it.

#3078639 Disassemble video of a 1200xl

Posted by Rybags on Tue Sep 23, 2014 9:26 PM

There's no video in that post I can see.


I DL'd the episode when someone mentioned it a few years back and put that segment on YT - gave my view count a nice boost it did:



#3077346 Flappy bird

Posted by Rybags on Mon Sep 22, 2014 3:56 AM

TBH, it's a shit game.  It's like a case of "mee-too-ism" that retro computers and consoles have people doing versions for them.

For actual good playable games like Line Runner, Cannanbalt and the like, it's a positive thing.

For junk like this - really, the time/effort would be way better expended on reproducing a game that's actually worth having in the first place.

#3076107 Repulse ;) Hmm RPC Games,...

Posted by Rybags on Sat Sep 20, 2014 5:43 AM

Lesson - don't come here acting with such contempt as to think you're the only person in the world actively developing software.

#3076067 Improve disk reading speed by sector order

Posted by Rybags on Sat Sep 20, 2014 3:54 AM

Normal format is close to optimum - but on a 1050 at least I found reading the sectors in reverse order each track is slightly faster.


Your problem is likely too many CIO calls per given amount of data and/or subsequent processing of the data is taking too long.

You'd probably be better off having a bigger buffer - load chunks of 1K or so then do the processing.  A pause every 8 sectors or so is more tolerable than every sector.


In any case, since your using CIO anyway, you're at the mercy of where whatever Dos wrote the files put them.  In theory you could change the layout so a file is spread among sectors differently but lots of work and no guarantee of benefit.

#3075897 Why didn't they make real arcade hardware for the home?

Posted by Rybags on Fri Sep 19, 2014 7:57 PM

A lot of arcade hw was specialized early on.  I've recently been looking at Missile Command - it uses a fixed bitmapping system where the last 32 lines is 3 bpp and the remainder only 2 bpp.  Also it has an addressing scheme such that most of the machine is only 15-bit addressing but the graphics can either be accessed by direct addressing or by (ind,X) which the board detects and alters the addressing such that the VRam is accessed such that a single pixel appears as the high 2 bits of data.


Some of the early Japanese games like Galaxian, Moon Cresta etc, Frogger used very similar hardware, some were interchangable.

Atari Lunar Lander, many machines were converted to Asteroids.


By the mid 80s, the likes of Atari System 1, 2 emerged, Sega and others had similar standards.


Overall though, arcade systems were usually much bulkier and specialised than an equivalent computer would have been.  And the interfacing was usually only to the point of recognising some DIP switches, the joysticks/buttons and coin registers.

Additionally the monitors were usually RGB which at the time was a somewhat expensive option for the home.  Doing video for RGB though is somewhat simpler than Chroma/Luma like most home systems did.


Why are todays consoles more advanced?  Probably because everyone who likes games either has a console and/or computer.  Arcade games are very much a niche market, often running the equivalent of an older PC hardware.


On that note though, it is good to see that a few pinballs are still being produced.  Arcade video games are simply a different physical presence where pinball is an entire sensation in itself which probably never will be faithfully reproduced on a computer monitor.

#3074856 Repulse ;) Hmm RPC Games,...

Posted by Rybags on Thu Sep 18, 2014 8:42 AM

Careful, Jose... you might end up in the class action deformation suite and on the Atariage Loser's page


:-o :grin:

#3073399 Is this available for jxd s7800?

Posted by Rybags on Tue Sep 16, 2014 3:05 AM

All you can do is try.  CPU speed for games is usually a recommendation.  The S7800 is Quad Core so that might help too.