Re: MC Interrupts
So the SAMs z80 really is actually slowed down quite considerably, I hadn`t
realised how much :(
Thanks for the details :)
Andrew Collier <[EMAIL PROTECTED]> wrote: On 17 May 2007, at 23:24, Calvin
Allett wrote:
>> Andrew Collier wrote:
>> Because of the Sam's memory timings, using JR is usually as fast (or
>> slightly faster than) using JP. That may change with Mayhem
>> accelerator!
> Thanks :) I`ve been reading the 1995 posts to the mailing list these
> past few days, and it`s amazing how much I`m picking up from
> those old old posts, so I`ve seen it mentioned that they run at around
> the same speed on SAM, am I remembering right that it depends
> where in screen the raster is when the code is run?
Yes. The Sam's ASIC deals with memory in blocks of 4 cycles at a
time, and also "steals" four cycles out of every eight while drawing
the screen (and also in some parts of the border, in MODE 1). In
general, this means that Sam cycle timings are usually the Z80's own
timings rounded up to a multiple of four, and then doubled if the
screen is on.
But a few instructions don't obey this rule, because they don't need
to read memory at the time ASIC reads it. So when the screen is on,
they "escape" part of the time doubling. JR is one of these
instructions, but JP is not.
On a raw Z80, on in a Sam running from external memory, and probably
in the Mayhem accelerator; JP takes 10 cycles, and JR takes 12 (or 7
for a conditional jump not taken).
In a Sam during the border, or if the screen is off, JP takes 12
cycles and also JR takes 12 cycles (a conditional jump which is not
taken, only takes 8 cycles).
When the screen is on, JP takes 24 cycles, but JR only takes 16 (a
conditional JR is 16 cycles whether taken or not).
HTH,
Andrew
--
--- Andrew Collier
http://www.intensity.org.uk/ ---
--
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Re: MC Interrupts
On 17 May 2007, at 23:24, Calvin Allett wrote: Andrew Collier <[EMAIL PROTECTED]> wrote: Because of the Sam's memory timings, using JR is usually as fast (or slightly faster than) using JP. That may change with Mayhem accelerator! Thanks :) I`ve been reading the 1995 posts to the mailing list these past few days, and it`s amazing how much I`m picking up from those old old posts, so I`ve seen it mentioned that they run at around the same speed on SAM, am I remembering right that it depends where in screen the raster is when the code is run? Yes. The Sam's ASIC deals with memory in blocks of 4 cycles at a time, and also "steals" four cycles out of every eight while drawing the screen (and also in some parts of the border, in MODE 1). In general, this means that Sam cycle timings are usually the Z80's own timings rounded up to a multiple of four, and then doubled if the screen is on. But a few instructions don't obey this rule, because they don't need to read memory at the time ASIC reads it. So when the screen is on, they "escape" part of the time doubling. JR is one of these instructions, but JP is not. On a raw Z80, on in a Sam running from external memory, and probably in the Mayhem accelerator; JP takes 10 cycles, and JR takes 12 (or 7 for a conditional jump not taken). In a Sam during the border, or if the screen is off, JP takes 12 cycles and also JR takes 12 cycles (a conditional jump which is not taken, only takes 8 cycles). When the screen is on, JP takes 24 cycles, but JR only takes 16 (a conditional JR is 16 cycles whether taken or not). HTH, Andrew -- --- Andrew Collier http://www.intensity.org.uk/ --- --
Re: MC Interrupts
Thanks :) I`ve been reading the 1995 posts to the mailing list these
past few days, and it`s amazing how much I`m picking up from
those old old posts, so I`ve seen it mentioned that they run at around
the same speed on SAM, am I remembering right that it depends
where in screen the raster is when the code is run?
Andrew Collier <[EMAIL PROTECTED]> wrote:
On 17 May 2007, at 22:17, Calvin Allett wrote:
> What`s the difference between a JP and a JR, I don`t even mean
> in T-States, but what varies between the way they work. If you`s
> don`t mind me asking ?
A JR takes less space, two bytes compared to a JP instruction which
takes 3. In a JR, you take your current address and add a one-byte
offset to it, so you can only jump approximately 128 bytes in either
direction (generally, the assembler will do this calculation for
you). In a JP instruction you specify an the whole two-byte
destination address and you jump exactly there.
Because of the Sam's memory timings, using JR is usually as fast (or
slightly faster than) using JP. That may change with Mayhem accelerator!
Andrew
--
--- Andrew Collier
http://www.intensity.org.uk/ ---
--
-
Yahoo! Answers - Got a question? Someone out there knows the answer. Tryit now.
RE: MC Interrupts
ly what you do is more like: Clear the grab buffers Loop: Set the display to page 1 Update your game logic, move the cars etc Put the contents of grab buffer 2 back in the old position for each sprite Grab the area under each sprite into their grab buffer 2, remember the position for redrawing Use the MC sprite routine to draw the sprites on page 2 in the positions Set the display to page 2, showing the sprites in the new position Update your game logic, move cars etc Put the contents of grab buffer 1 back in the old position for each sprite Grab the area under each sprite into their grab buffer 1, remember the position for redrawing Use the MC sprite routine to draw the sprites on page 1 in the positions Repeat This is a little more tricky as you have to keep 2 copies of the grab buffer (one for each screen, apparently some people say you can do it with one buffer but ive not had much luck with that). It depends on the MC routine, some do know about the Screen/display commands, some dont, its not always that hard to alter. The grabbing is a similar MC routine. Adrian From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Calvin Allett Sent: 16 May 2007 02:46 To: Adrian Subject: RE: MC Interrupts `Did someone call? ;) Yes it was the early issues, it was issues 1-5 i think, ` i was only talking to colin this evening about that, now ive moved i ` really need to get on with finishing it, although i lost all my code ` when i lost the sam harddrive. Ive now got a sam in a can and have ` some new flash cards on order so ill get back to it and finish the ` little game, maybe some articles on learning mc can be arranged. A S-I-A-Can Lucky Bas... erm... I mean sweet :D I haven`t got the articles in question, but meaning to get those issue`s, so if you`ll be hopefully doing more then that`s brilliant. `To use something like that from basic, you could just do the following ` (this is off the top of my head after a bottle of wine, so it maybe ` wrong ;) ) But each frame you could do the following (its basically ` a double buffer system but from basic). When i say page 1, page 2 ` i dont mean physical memory pages, but any particular page, again ` from memory it might have been the screen command that allowed you ` to open up and use different screens. If you dont know then ill ` try and dig up the info tomorrow. Yeah, your right, it`s the Screen command, with also the Display command for the flipping.. :) Would a MC routine, know which area in RAM to draw too, if Basic was flipping screens though, just thought. OR could a copy of a routine be used to either draw to screen 1 or 2, so from Basic call the correct one? I`m never sure if you can have a small MC routine, and a copy, because if they both need to be paged in or whatever... `IN BASIC: ` `Set the display to page 1` ` `Update your game logic, move the cars etc` ` `Use the MC sprite routine to draw the sprites on page 2 in the positions` ` `Set the display to page 2, showing the sprites in the new position` ` ` Update your game logic, move cars etc ` `Use the MC sprite routine to draw the sprites on page 1 in the positions ` ` ` ` Repeat ;) ` ` ` `You still need to either A) handle storing what was under the sprites ` and putting it back, or B) just redraw the entire screen before you ` draw the sprites. B) is the easiest to start with but can be slow, ` but the key is to get things working then speed them up. Doing this ` you are only actually updating when you want to, you dont need interrupts, ` you dont need anything clever in MC to do checking etc. I`ve tried drawing the complete (well 2/3rd`s of the screen) using double buffering in `Jimf `n Oobs` and it knocks it to about 4 fps, so been thinking of for a car game, defining area`s where cars may be, since the tracks will only be about 24 pixels high or wide and drawing that if a car/s is in that region, this shouldn`t be much of a problem... I`ll try and knock up a demo of what I have in mind over the next few days, and you can hopefully see whether or not you think a MC routine would be possible/beneficial :) `I might be completely off track here, so let me know J `Adrian. Your not ;) Oh, and `off track` very good, is that a pun :) Cal... - The all-new Yahoo! Mail goes wherever you go - free your email address from your Internet provider. - APB Computer Services Ltd. Registered Address: 3 Springfield, Trevadlock, Congdons
Re: MC Interrupts
Ah sweet :) soz for delay, just spent 45 mins typing another reply ! Handy command then JR Colin Piggot <[EMAIL PROTECTED]> wrote: > What`s the difference between a JP and a JR, I don`t even mean > in T-States, but what varies between the way they work. If you`s > don`t mind me asking ? JP reads in two bytes more to use as an address to jump to. JR reads in only one more byte, to use as an offset from the current address to jump to. Colin = Quazar : Hardware, Software, Spares and Repairs for the Sam Coupe 1995-2007 - Celebrating 12 Years of developing for the Sam Coupe Website: http://www.samcoupe.com/ - Yahoo! Answers - Got a question? Someone out there knows the answer. Tryit now.
RE: MC Interrupts
the display to page 2, showing the sprites in the new position Update your game logic, move cars etc Put the contents of grab buffer 1 back in the old position for each sprite Grab the area under each sprite into their grab buffer 1, remember the position for redrawing Use the MC sprite routine to draw the sprites on page 1 in the positions Repeat This is a little more tricky as you have to keep 2 copies of the grab buffer (one for each screen, apparently some people say you can do it with one buffer but ive not had much luck with that). It depends on the MC routine, some do know about the Screen/display commands, some dont, its not always that hard to alter. The grabbing is a similar MC routine. Adrian From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Calvin Allett Sent: 16 May 2007 02:46 To: Adrian Subject: RE: MC Interrupts `Did someone call? ;) Yes it was the early issues, it was issues 1-5 i think, ` i was only talking to colin this evening about that, now ive moved i ` really need to get on with finishing it, although i lost all my code ` when i lost the sam harddrive. Ive now got a sam in a can and have ` some new flash cards on order so ill get back to it and finish the ` little game, maybe some articles on learning mc can be arranged. A S-I-A-Can Lucky Bas... erm... I mean sweet :D I haven`t got the articles in question, but meaning to get those issue`s, so if you`ll be hopefully doing more then that`s brilliant. `To use something like that from basic, you could just do the following ` (this is off the top of my head after a bottle of wine, so it maybe ` wrong ;) ) But each frame you could do the following (its basically ` a double buffer system but from basic). When i say page 1, page 2 ` i dont mean physical memory pages, but any particular page, again ` from memory it might have been the screen command that allowed you ` to open up and use different screens. If you dont know then ill ` try and dig up the info tomorrow. Yeah, your right, it`s the Screen command, with also the Display command for the flipping.. :) Would a MC routine, know which area in RAM to draw too, if Basic was flipping screens though, just thought. OR could a copy of a routine be used to either draw to screen 1 or 2, so from Basic call the correct one? I`m never sure if you can have a small MC routine, and a copy, because if they both need to be paged in or whatever... `IN BASIC: ` `Set the display to page 1` ` `Update your game logic, move the cars etc` ` `Use the MC sprite routine to draw the sprites on page 2 in the positions` ` `Set the display to page 2, showing the sprites in the new position` ` ` Update your game logic, move cars etc ` `Use the MC sprite routine to draw the sprites on page 1 in the positions ` ` ` ` Repeat ;) ` ` ` `You still need to either A) handle storing what was under the sprites ` and putting it back, or B) just redraw the entire screen before you ` draw the sprites. B) is the easiest to start with but can be slow, ` but the key is to get things working then speed them up. Doing this ` you are only actually updating when you want to, you dont need interrupts, ` you dont need anything clever in MC to do checking etc. I`ve tried drawing the complete (well 2/3rd`s of the screen) using double buffering in `Jimf `n Oobs` and it knocks it to about 4 fps, so been thinking of for a car game, defining area`s where cars may be, since the tracks will only be about 24 pixels high or wide and drawing that if a car/s is in that region, this shouldn`t be much of a problem... I`ll try and knock up a demo of what I have in mind over the next few days, and you can hopefully see whether or not you think a MC routine would be possible/beneficial :) `I might be completely off track here, so let me know J `Adrian. Your not ;) Oh, and `off track` very good, is that a pun :) Cal... - The all-new Yahoo! Mail goes wherever you go - free your email address from your Internet provider. - APB Computer Services Ltd. Registered Address: 3 Springfield, Trevadlock, Congdons Shop, Launceston, Cornwall, PL15 7PW. Registration Number: 4942193. V.A.T. No: 826 0005 70 - This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you s
Re: MC Interrupts
On 17 May 2007, at 22:17, Calvin Allett wrote: What`s the difference between a JP and a JR, I don`t even mean in T-States, but what varies between the way they work. If you`s don`t mind me asking ? A JR takes less space, two bytes compared to a JP instruction which takes 3. In a JR, you take your current address and add a one-byte offset to it, so you can only jump approximately 128 bytes in either direction (generally, the assembler will do this calculation for you). In a JP instruction you specify an the whole two-byte destination address and you jump exactly there. Because of the Sam's memory timings, using JR is usually as fast (or slightly faster than) using JP. That may change with Mayhem accelerator! Andrew -- --- Andrew Collier http://www.intensity.org.uk/ --- --
Re: MC Interrupts
> What`s the difference between a JP and a JR, I don`t even mean > in T-States, but what varies between the way they work. If you`s > don`t mind me asking ? JP reads in two bytes more to use as an address to jump to. JR reads in only one more byte, to use as an offset from the current address to jump to. Colin = Quazar : Hardware, Software, Spares and Repairs for the Sam Coupe 1995-2007 - Celebrating 12 Years of developing for the Sam Coupe Website: http://www.samcoupe.com/
RE: MC Interrupts
What`s the difference between a JP and a JR, I don`t even mean in T-States, but what varies between the way they work. If you`s don`t mind me asking ? Cal... `Geoff Winkless <[EMAIL PROTECTED]> wrote:`Geoff Winkless wrote: > Anyway, something like: [snip] Sorry, it's been a while and I was tired (!!), those local JP's should all (of course) be JR's! Geoff __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - New Yahoo! Mail is the ultimate force in competitive emailing. Find out more at the Yahoo! Mail Championships. Plus: play games and win prizes.
RE: MC Interrupts
Geoff Winkless wrote: > Anyway, something like: [snip] Sorry, it's been a while and I was tired (!!), those local JP's should all (of course) be JR's! Geoff __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
RE: MC Interrupts
Dont worry about the speed, just order a mayhem accelerator ;) But yes, redrawing the entire screen can be very slow. Ideally what you do is more like: Clear the grab buffers Loop: Set the display to page 1 Update your game logic, move the cars etc Put the contents of grab buffer 2 back in the old position for each sprite Grab the area under each sprite into their grab buffer 2, remember the position for redrawing Use the MC sprite routine to draw the sprites on page 2 in the positions Set the display to page 2, showing the sprites in the new position Update your game logic, move cars etc Put the contents of grab buffer 1 back in the old position for each sprite Grab the area under each sprite into their grab buffer 1, remember the position for redrawing Use the MC sprite routine to draw the sprites on page 1 in the positions Repeat This is a little more tricky as you have to keep 2 copies of the grab buffer (one for each screen, apparently some people say you can do it with one buffer but ive not had much luck with that). It depends on the MC routine, some do know about the Screen/display commands, some don't, its not always that hard to alter. The grabbing is a similar MC routine. Adrian From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Calvin Allett Sent: 16 May 2007 02:46 To: Adrian Subject: RE: MC Interrupts `Did someone call? ;) Yes it was the early issues, it was issues 1-5 i think, ` i was only talking to colin this evening about that, now ive moved i ` really need to get on with finishing it, although i lost all my code ` when i lost the sam harddrive. Ive now got a sam in a can and have ` some new flash cards on order so ill get back to it and finish the ` little game, maybe some articles on learning mc can be arranged. A S-I-A-Can Lucky Bas... erm... I mean sweet :D I haven`t got the articles in question, but meaning to get those issue`s, so if you`ll be hopefully doing more then that`s brilliant. `To use something like that from basic, you could just do the following ` (this is off the top of my head after a bottle of wine, so it maybe ` wrong ;) ) But each frame you could do the following (its basically ` a double buffer system but from basic). When i say page 1, page 2 - ` i don't mean physical memory pages, but any particular page, again ` from memory it might have been the screen command that allowed you ` to open up and use different screens. If you don't know then ill ` try and dig up the info tomorrow. Yeah, your right, it`s the Screen command, with also the Display command for the flipping.. :) Would a MC routine, know which area in RAM to draw too, if Basic was flipping screens though, just thought. OR could a copy of a routine be used to either draw to screen 1 or 2, so from Basic call the correct one? I`m never sure if you can have a small MC routine, and a copy, because if they both need to be paged in or whatever... `IN BASIC: ` `Set the display to page 1` ` `Update your game logic, move the cars etc` ` `Use the MC sprite routine to draw the sprites on page 2 in the positions` ` `Set the display to page 2, showing the sprites in the new position` ` ` Update your game logic, move cars etc ` `Use the MC sprite routine to draw the sprites on page 1 in the positions ` ` ` ` Repeat ;) ` ` ` `You still need to either A) handle storing what was under the sprites ` and putting it back, or B) just redraw the entire screen before you ` draw the sprites. B) is the easiest to start with but can be slow, ` but the key is to get things working then speed them up. Doing this ` you are only actually updating when you want to, you don't need interrupts, ` you don't need anything clever in MC to do checking etc. I`ve tried drawing the complete (well 2/3rd`s of the screen) using double buffering in `Jimf `n Oobs` and it knocks it to about 4 fps, so been thinking of for a car game, defining area`s where cars may be, since the tracks will only be about 24 pixels high or wide and drawing that if a car/s is in that region, this shouldn`t be much of a problem... I`ll try and knock up a demo of what I have in mind over the next few days, and you can hopefully see whether or not you think a MC routine would be possible/beneficial :) `I might be completely off track here, so let me know J `Adrian. Your not ;) Oh, and `off track` very good, is that a pun :) Cal... The all-new Yahoo! Mail <http://us.rd.yahoo.com/mail/uk/taglines/default/nowyoucan/free_from_isp /*http:/us.rd.yahoo.com/evt=40565/*http:/uk.docs.yahoo.com/nowyoucan.htm l> goes wherever you go - free your e
RE: MC Interrupts
`Did someone call? ;) Yes it was the early issues, it was issues 1-5 i think, ` i was only talking to colin this evening about that, now ive moved i ` really need to get on with finishing it, although i lost all my code ` when i lost the sam harddrive. Ive now got a sam in a can and have ` some new flash cards on order so ill get back to it and finish the ` little game, maybe some articles on learning mc can be arranged. A S-I-A-Can Lucky Bas... erm... I mean sweet :D I haven`t got the articles in question, but meaning to get those issue`s, so if you`ll be hopefully doing more then that`s brilliant. `To use something like that from basic, you could just do the following ` (this is off the top of my head after a bottle of wine, so it maybe ` wrong ;) ) But each frame you could do the following (its basically ` a double buffer system but from basic). When i say page 1, page 2 ` i dont mean physical memory pages, but any particular page, again ` from memory it might have been the screen command that allowed you ` to open up and use different screens. If you dont know then ill ` try and dig up the info tomorrow. Yeah, your right, it`s the Screen command, with also the Display command for the flipping.. :) Would a MC routine, know which area in RAM to draw too, if Basic was flipping screens though, just thought. OR could a copy of a routine be used to either draw to screen 1 or 2, so from Basic call the correct one? I`m never sure if you can have a small MC routine, and a copy, because if they both need to be paged in or whatever... `IN BASIC: ` `Set the display to page 1` ` `Update your game logic, move the cars etc` ` `Use the MC sprite routine to draw the sprites on page 2 in the positions` ` `Set the display to page 2, showing the sprites in the new position` ` ` Update your game logic, move cars etc ` `Use the MC sprite routine to draw the sprites on page 1 in the positions ` ` ` ` Repeat ;) ` ` ` `You still need to either A) handle storing what was under the sprites ` and putting it back, or B) just redraw the entire screen before you ` draw the sprites. B) is the easiest to start with but can be slow, ` but the key is to get things working then speed them up. Doing this ` you are only actually updating when you want to, you dont need interrupts, ` you dont need anything clever in MC to do checking etc. I`ve tried drawing the complete (well 2/3rd`s of the screen) using double buffering in `Jimf `n Oobs` and it knocks it to about 4 fps, so been thinking of for a car game, defining area`s where cars may be, since the tracks will only be about 24 pixels high or wide and drawing that if a car/s is in that region, this shouldn`t be much of a problem... I`ll try and knock up a demo of what I have in mind over the next few days, and you can hopefully see whether or not you think a MC routine would be possible/beneficial :) `I might be completely off track here, so let me know J `Adrian. Your not ;) Oh, and `off track` very good, is that a pun :) Cal... - The all-new Yahoo! Mail goes wherever you go - free your email address from your Internet provider.
RE: MC Interrupts
Did someone call? ;) Yes it was the early issues, it was issues 1-5 i think, i was only talking to colin this evening about that, now ive moved i really need to get on with finishing it, although i lost all my code when i lost the sam harddrive. Ive now got a sam in a can and have some new flash cards on order so ill get back to it and finish the little game, maybe some articles on learning mc can be arranged. Compiled sprites are (if im not mistaken) the fastest way to draw things on the sam. To use something like that from basic, you could just do the following (this is off the top of my head after a bottle of wine, so it maybe wrong ;) ) But each frame you could do the following (its basically a double buffer system but from basic). When i say page 1, page 2 - i don't mean physical memory pages, but any particular page, again from memory it might have been the screen command that allowed you to open up and use different screens. If you don't know then ill try and dig up the info tomorrow. IN BASIC: Set the display to page 1 Update your game logic, move the cars etc Use the MC sprite routine to draw the sprites on page 2 in the positions Set the display to page 2, showing the sprites in the new position Update your game logic, move cars etc Use the MC sprite routine to draw the sprites on page 1 in the positions Repeat ;) You still need to either A) handle storing what was under the sprites and putting it back, or B) just redraw the entire screen before you draw the sprites. B) is the easiest to start with but can be slow, but the key is to get things working then speed them up. Doing this you are only actually updating when you want to, you don't need interrupts, you don't need anything clever in MC to do checking etc. I might be completely off track here, so let me know J Adrian. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Calvin Allett Sent: 15 May 2007 23:31 To: Adrian Subject: Re: MC Interrupts no probs mate, I`m not exactly gonna be able to do anything with any MC code yet anyhow, and I know your busy :) I do love looking through the issue`s I have, it always eggs me on to do more coding, but I need to get the early issue`s especially for the (sounding great) articles :D [EMAIL PROTECTED] wrote: Quoting Calvin Allett : > I still need to catch up on the later issue`s, and the earlier > ones... I`d forgot there was such an article, but I`d heard, one of > the early ones I think :) > I've got a site to work on tonight, otherwise I'd be dipping in my issues to look for you :( To help you stay safe and secure online, we've developed the all new Yahoo! Security Centre <http://us.rd.yahoo.com/mail/uk/taglines/default/security_centre/*http:/ uk.security.yahoo.com/> . APB Computer Services Ltd. Registered Address: 3 Springfield, Trevadlock, Congdons Shop, Launceston, Cornwall, PL15 7PW. Registration Number: 4942193. V.A.T. No: 826 0005 70 This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.
Re: MC Interrupts
no probs mate, I`m not exactly gonna be able to do anything with any MC code yet anyhow, and I know your busy :) I do love looking through the issue`s I have, it always eggs me on to do more coding, but I need to get the early issue`s especially for the (sounding great) articles :D [EMAIL PROTECTED] wrote: Quoting Calvin Allett : > I still need to catch up on the later issue`s, and the earlier > ones... I`d forgot there was such an article, but I`d heard, one of > the early ones I think :) > I've got a site to work on tonight, otherwise I'd be dipping in my issues to look for you :( - To help you stay safe and secure online, we've developed the all new Yahoo! Security Centre.
Re: MC Interrupts
Quoting Calvin Allett <[EMAIL PROTECTED]>: I still need to catch up on the later issue`s, and the earlier ones... I`d forgot there was such an article, but I`d heard, one of the early ones I think :) I've got a site to work on tonight, otherwise I'd be dipping in my issues to look for you :(
Re: MC Interrupts
I still need to catch up on the later issue`s, and the earlier ones... I`d forgot there was such an article, but I`d heard, one of the early ones I think :) [EMAIL PROTECTED] wrote: Quoting Calvin Allett : > I`ve come across a little routine on an old disk magazine that > provides four 8*8 pixel masked `sprites` via a MC interrupt routine, > it seems pretty fast, and am wondering about trying to use it, > however I`m wondering if it`s possible to alter an interrupt routine > so that it only runs the code every 2nd or third frame? I also seem to recall a pretty decent Sprite article in SAM Revival... can't recall the issue - but it was from that clever chap Adrian (Brown, I think?) - Yahoo! Mail is the world's favourite email. Don't settle for less, sign up for your freeaccount today.
Re: MC Interrupts
Quoting Calvin Allett <[EMAIL PROTECTED]>: I`ve come across a little routine on an old disk magazine that provides four 8*8 pixel masked `sprites` via a MC interrupt routine, it seems pretty fast, and am wondering about trying to use it, however I`m wondering if it`s possible to alter an interrupt routine so that it only runs the code every 2nd or third frame? I also seem to recall a pretty decent Sprite article in SAM Revival... can't recall the issue - but it was from that clever chap Adrian (Brown, I think?)
Re: MC Interrupts
Quoting Calvin Allett <[EMAIL PROTECTED]>: I used to love these demo`s, and the converted games, as I still usually prefer AY music over The Sound Machine, or E-tracker, although some SAM tunes blow the AY away :) I was thinking it might be easier to get someone to do a tune or two for games, if I needed an AY tune over an SAA as the scenes bigger. There's always the SID player as well :-) (Although you do need a SID chip for this... ;))
Re: MC Interrupts
Quoting Colin Piggot <[EMAIL PROTECTED]>: Interrupts aren't affected by the speed of the machine. The ASIC generates the frame interrupt every 50th of a second, it's all tied right into the video timings. So things like music players, or any frame interrupt (or line interrupt) routines don't need to be changed at all. I guess you could do much more in between the interrupts however :-)
Re: MC Interrupts
Calvin Allett wrote: > I`ve been wondering this before, in relation to the Mayhem > accelerator, as if wanting to write a game to run at 20Mhz > (about four times normal speed with uncontended RAM?) > then if I`d be able to run an intterupt music player, but have > the player altered to only play the music every 4th frame, > to keep tune at correct speed approx? `Interrupts aren't affected by the speed of the machine. ` `The ASIC generates the frame interrupt every 50th of a second, it's all `tied `right into the video timings. So things like music players, or any `frame `interrupt (or line interrupt) routines don't need to be changed at all. I knew that I was possibly talking crap :D I should have realised actually, so that`s really cool, so you still get your 50 interrupts, but just more you can do between them. > Oh, and while I`m rambling, does anybody know if there exists > an interrupt player for AY music, or just players to incorporate > into MC? `I don't recall seeing any standalone interrupt players to play AY `music, `although Cookie and Stefan have in the past written patches into the `various `128K demos they both converted to play the music through the SAA1099 so `they've done the main bit of work of converting AY register data into `the `nearest equivalent for the SAA. ` I used to love these demo`s, and the converted games, as I still usually prefer AY music over The Sound Machine, or E-tracker, although some SAM tunes blow the AY away :) I was thinking it might be easier to get someone to do a tune or two for games, if I needed an AY tune over an SAA as the scenes bigger. --- ` `Could be a bit more tricky if you are meaning to play .AY files, which `are `essentially the speccy machine code player and the data that would `need `the machine code part (which I guess is specific to the tune and the `programmer who wrote the player) to be patched to play through the SAA `etc. Damn, really didn`t know this, I thought that the .AY files were just data for the soundchip, although having heard 48K beeper and 128K AY in the format, I should have realised it included the player :( Thanks for info Colin, I`d misunderstood both things, erm ;) Cal... - What kind of emailer are you? Find out today - get a free analysis of your email personality. Take the quiz at the Yahoo! Mail Championship.
RE: MC Interrupts
Calvin Allett wrote: > so would it seem feasable to be able to alter the routine > with a flag, so that it jumps straight back every other frame > and only draws the other frames? "`Assuming you don't need to worry about redrawing them if they haven't `moved `you could simply add your own interrupt handler to check whether the `positions are the same and don't call the sprite routine if they are. ` `If your BASIC program _is_ changing the display then you will have to `call `them every frame anyway, since the masks will go horribly wrong `otherwise `(in fact, won't they anyway?)" The game I`m thinking is a simplistic Super Sprint type game, and they`d be travelling over road graphics that wouldn`t be changing, so that`s not a problem, but I see what you mean. i hadn`t thought of actually adding in anything to the routine, apart from wondering if it could be slowed down to not run as often, and give more speed to Basic, but your idea sounds even better, checking the coords and only changing/drawing if they change :) that sounds to be the best. -- `I'm confused why you'd want to fake hardware sprites with interrupts `anyway, `why not just write some MC to blat the sprite and call it from your `BASIC `routine? That gives much more fine-grained control. I don`t know :D I`m loving the extra speed of the Put command in MasterBasic, and just wanting/needing more speed than the generic routine offers, and coming across this little 4 `sprite` routine just got me excited (even if it`s only 8*8 graphics)... It would actually be better to use a routine that I could Call when required, and not waste time though... never been a fan of interrupts in Basic, as they slow it down terribly :) `Anyway, something like: ` `MyInt: ` PUSH HL ` PUSH BC `Sprite1: `LD BC, `LD HL, (SpritePos1) `SBC HL, BC `JP Z, GoSprites `Sprite2: `LD BC, `LD HL, (SpritePos2) `SBC HL, BC `JP NZ, GoSprites `Sprite3: `LD BC, `LD HL, (SpritePos3) `SBC HL, BC `JP NZ, GoSprites `Sprite4: `LD BC, `LD HL, (SpritePos4) `SBC HL, BC `JP NZ, GoSprites ` POP BC ` POP HL `reti `GoSprites: `LD HL, (SpritePos1) `LD (Sprite1+1), HL `LD HL, (SpritePos2) `LD (Sprite2+1), HL `LD HL, (SpritePos3) `LD (Sprite3+1), HL `LD HL, (SpritePos4) `LD (Sprite4+1), HL ` POP BC ` POP HL `JP OldHandler ` `It's not exactly optimal but it's fairly obvious what it does. ` hehe, cheers for the example Geoff, but I`m afraid I`m still to learn MC, I can understand the LD commands, and i think I`ve got the general idea of what POPs and JP`s do, but as soon as I start to think about having to have graphics in special formats etc it puts me off learning MC... I have dl`d some MC books from WoSpec recently though *_+ thanks again :) Cal... - Yahoo! Answers - Got a question? Someone out there knows the answer. Tryit now.
Re: MC Interrupts
Calvin Allett wrote: > I`ve been wondering this before, in relation to the Mayhem > accelerator, as if wanting to write a game to run at 20Mhz > (about four times normal speed with uncontended RAM?) > then if I`d be able to run an intterupt music player, but have > the player altered to only play the music every 4th frame, > to keep tune at correct speed approx? Interrupts aren't affected by the speed of the machine. The ASIC generates the frame interrupt every 50th of a second, it's all tied right into the video timings. So things like music players, or any frame interrupt (or line interrupt) routines don't need to be changed at all. > Oh, and while I`m rambling, does anybody know if there exists > an interrupt player for AY music, or just players to incorporate > into MC? I don't recall seeing any standalone interrupt players to play AY music, although Cookie and Stefan have in the past written patches into the various 128K demos they both converted to play the music through the SAA1099 so they've done the main bit of work of converting AY register data into the nearest equivalent for the SAA. Could be a bit more tricky if you are meaning to play .AY files, which are essentially the speccy machine code player and the data that would need the machine code part (which I guess is specific to the tune and the programmer who wrote the player) to be patched to play through the SAA etc. Colin = Quazar : Hardware, Software, Spares and Repairs for the Sam Coupe 1995-2007 - Celebrating 12 Years of developing for the Sam Coupe Website: http://www.samcoupe.com/
RE: MC Interrupts
Calvin Allett wrote: > so would it seem feasable to be able to alter the routine > with a flag, so that it jumps straight back every other frame > and only draws the other frames? Assuming you don't need to worry about redrawing them if they haven't moved you could simply add your own interrupt handler to check whether the positions are the same and don't call the sprite routine if they are. If your BASIC program _is_ changing the display then you will have to call them every frame anyway, since the masks will go horribly wrong otherwise (in fact, won't they anyway?) I'm confused why you'd want to fake hardware sprites with interrupts anyway, why not just write some MC to blat the sprite and call it from your BASIC routine? That gives much more fine-grained control. Anyway, something like: MyInt: PUSH HL PUSH BC Sprite1: LD BC, LD HL, (SpritePos1) SBC HL, BC JP Z, GoSprites Sprite2: LD BC, LD HL, (SpritePos2) SBC HL, BC JP NZ, GoSprites Sprite3: LD BC, LD HL, (SpritePos3) SBC HL, BC JP NZ, GoSprites Sprite4: LD BC, LD HL, (SpritePos4) SBC HL, BC JP NZ, GoSprites POP BC POP HL reti GoSprites: LD HL, (SpritePos1) LD (Sprite1+1), HL LD HL, (SpritePos2) LD (Sprite2+1), HL LD HL, (SpritePos3) LD (Sprite3+1), HL LD HL, (SpritePos4) LD (Sprite4+1), HL POP BC POP HL JP OldHandler It's not exactly optimal but it's fairly obvious what it does. Geoff __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
