Amiga questions you've always been too embarrassed to ask - Page 116

chb · 15 August 2019, 14:58

Quote:

Originally Posted by jolly11

thanks..I know but the image was on a magazine and it was very small..
the advertise says "probably the smallest 20mb hard disk in the world; it fits internally on your amiga 500; autoboot with kickstart 1.3; autoparking; compatible with adspeed accelerator"

There was an AdSpeed accelerator with IDE controller, maybe it's your device?
https://www.bigbookofamigahardware.c...uct.aspx?id=74

Anyway, wasn't there a name mentioned in the advertisement? Was is from a dealer?

jolly11 · 15 August 2019, 15:17

Quote:

Originally Posted by chb

There was an AdSpeed accelerator with IDE controller, maybe it's your device?
https://www.bigbookofamigahardware.c...uct.aspx?id=74

Anyway, wasn't there a name mentioned in the advertisement? Was is from a dealer?

I usually read http://www.old-computer-mags.net/oldmags/

and I was reading this http://www.old-computer-mags.net/oldmags/20/K/463
and if you go to page 58 you'll find the advertisment..I can't find further info

zipper · 15 August 2019, 20:43

ICD AdIDE 44 (Novia) for 2.5" internal drives . http://amiga.resource.cx/exp/adide

Jope · 17 August 2019, 08:31

My guess is also the AdIDE.

d4rk3lf · 21 August 2019, 22:09

When I worked on TV, we had Pal Standard, and maximum res was 768x576 (if I remember correctly).
This is max resolution I could render my 3D intros, and had to check "lower field first", in my 3D app, otherwise it would flicker...
Now, I know they used (before I get the job) Amiga, and Skala app to drive some static commercials, and animated stuff.

Today, when I type in my Dpaint res 768*576 (on my Amiga 500, and fairly new crt TV), I got flicker. If I reduce it, I got flicker.

Questions:
1) I thought that Amiga (on the go) supported Pal TV res. What is the max A500 res can support without flicker?
2) What is the native A500 res (if there's anything like that). Like res, in what the most games are done (talking about big titles like: Turrican, Ruff'n'Tumble, Shadow of the beast... etc).
3) I know that "flickerfixer" was inside A3000. So, I always thought that it would fix res flickering beyond pal (tv capabilities). Does it fix that? Can you display (with flicker fixer) 1280x720 res on a standard crt TV?

And fourth question is never asked before, but:
Was anyone else disappointed with the A1200?

demolition · 21 August 2019, 22:51

PAL is interlaced so it flickers. All TV shows, commercials etc. had to be interlaced however if the two fields were not that different then the flicker would not be as noticeable.
Amiga is almost PAL - the clock is slightly off but it is close enough so a TV would not mind. PAL has 625 lines, however only 576 of them carries video. With full overscan in PAL mode, Amiga should be able to show up to 566 lines as far as I can find (without overscan, PAL interlaced is 640x512).

Most games run in low res which is 320x256 and typically only uses 200 of those 256 lines to make it easy to make both a PAL and an NTSC version of the same game (NTSC has fewer lines).

A flickerfixer cannot be used with a regular TV. You need a VGA or multisync monitor to show a progressive (non-interlaced) image.

Magic · 22 August 2019, 06:07

Does a RTOS (real time operating system) exist for the Amiga?

demolition · 22 August 2019, 06:39

Quote:

Originally Posted by Magic

Does a RTOS (real time operating system) exist for the Amiga?

I would say that AmigaOS qualifies as an RTOS. You can disable the system and disable interrupts (minus NMI) so you have complete control over the system if you need to do timing critical stuff.

d4rk3lf · 22 August 2019, 13:58

Thanks Demolition.
You are always of great help to us noobs.

Jope · 24 August 2019, 12:33

Quote:

Originally Posted by demolition

I would say that AmigaOS qualifies as an RTOS. You can disable the system and disable interrupts (minus NMI) so you have complete control over the system if you need to do timing critical stuff.

If you take over the system, AmigaOS is no longer running. No OS so no RTOS unless you write one yourself. :-)

I would say AmigaOS does not qualify as an RTOS.

https://en.wikipedia.org/wiki/Real-t...erating_system

meynaf · 24 August 2019, 13:35

Quote:

Originally Posted by Jope

If you take over the system, AmigaOS is no longer running. No OS so no RTOS unless you write one yourself. :-)

I would say AmigaOS does not qualify as an RTOS.

https://en.wikipedia.org/wiki/Real-t...erating_system

AmigaOS is soft RTOS, not hard RTOS, but nevertheless, if running under OS you can still perform tasks with sub-millisecond accuracy which is better than many "true" RTOS. It also does have pretty stable timings, even though there is no guarantee on them. It's not for nothing NASA used miggies for so long.

So for me, yes it does qualify.

Jope · 24 August 2019, 19:49

Yeah, I guess with law abiding software it is possible to get that kind of performance. However there are no guarantees about anything given by AmigaOS and software can hog the whole system at any given time without the OS doing anything. :-)

malko · 24 August 2019, 23:34

Quote:

Originally Posted by meynaf

AmigaOS is soft RTOS, not hard RTOS, but nevertheless, if running under OS you can still perform tasks with sub-millisecond accuracy which is better than many "true" RTOS. It also does have pretty stable timings, even though there is no guarantee on them. It's not for nothing NASA used miggies for so long.

So for me, yes it does qualify.

+1

Maybe NASA should have kept their Amigas running

(g@@gle translatet link)

Glen M · 03 September 2019, 15:48

Why is chip ram limited to 2mb?

Since the A1200 has a chip ram expansion header that is unused is there any possibility of it being used even for fast ram?

I understand the header is there because at one time the A1200 was going to ship with 1mb of ram allowing you to add the other 1mb later but why was the header fitted in factory?

Makes me wonder if AGA was meant to have facility for more chipram but left out last minute because typical commodore. Wouldn't it be a laugh if there was some jumper undocumented somewhere hiding on our AGA machines to enable 4mb chipram (I know there isn't)

And since I'm asking stupid questions... how does WinUAE make provision for up to 8mb of chip ram and would there be any possibility of a custom chip to make it work on the real machine?

demolition · 03 September 2019, 16:57

The header is called a clock port because it is the place to add... an RTC.

It cannot be used for fast RAM. And the header is not always fitted. Some motherboards have it, some don't.

CrazyPepsi · 03 September 2019, 19:36

here is one How did they make the music they cracked to the games the intros i mean

nogginthenog · 03 September 2019, 19:44

Quote:

Originally Posted by Glen M

Makes me wonder if AGA was meant to have facility for more chipram but left out last minute because typical commodore. Wouldn't it be a laugh if there was some jumper undocumented somewhere hiding on our AGA machines to enable 4mb chipram (I know there isn't)

The A4000 motherboard has a jumper for 8Mb chipram. AKA the "Free sex and beer" jumper. It doesn't work though

Clearly shows C= was planning more chip.

Daedalus · 03 September 2019, 23:26

The custom chips are basically lacking the physical address lines to use more chip RAM. WinUAE doesn't have such physical constraints, so it's able to open up the addressing to a larger area. The Zorro-II expansion area is directly above the chip RAM area in the Amiga memory map, so chip RAM can in theory be extended into that area. As it stands however, RAM that's added in that area is classified as fast RAM because the chipset can't access it.

To make the WinUAE method work on real hardware, you would need to replace the chipset (or at least some of the chips - Alice in particular), the bus / RAM controllers (Bridgette, Budgie), and some of the supporting logic and board traces. Doable, but it might be simpler to just use a Vampire, which is similar to WinUAE in that it side steps the physical limitations of the original chips.

matburton · 01 October 2019, 19:06

OK here's mine

Why 8 bits in a byte?

So that makes sense to me for the 8-bit machine era. It looks like they typically had 8 data bus lines. But why have addresses which overlap data-wise on the Amiga when it has a 16-bit data bus? It seems even more strange when you consider that using 8-bit ops on the M68k sometimes need more cycles, and that you can't fetch unaligned words. Were there any computers in that era that bucked the 8-bit trend?

Looking at the KS1.3 EXEC library it seems that most pointers are BPTRs, which point to a word. Does that mean that it wasn't clear whether an address per 8-bits was going to be a thing until late in development?

nogginthenog · 01 October 2019, 20:22

It's only DOS that uses BPTRs due to its TripOS legacy (developed at the University of Cambridge BTW). EXEC doesn't use BPTRs as far as I know.

If you're interested in TripOS and the Amiga Dr Tim King gave a nice speech at Amiga32. Probably on YouTube.

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15 August 2019, 20:43	#2303
zipper Registered User Join Date: Mar 2004 Location: finland Posts: 1,841	ICD AdIDE 44 (Novia) for 2.5" internal drives . http://amiga.resource.cx/exp/adide

17 August 2019, 08:31	#2304
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,910	My guess is also the AdIDE.

21 August 2019, 22:09	#2305
d4rk3lf Registered User Join Date: Jul 2015 Location: Novi Sad, Serbia Posts: 1,693	When I worked on TV, we had Pal Standard, and maximum res was 768x576 (if I remember correctly). This is max resolution I could render my 3D intros, and had to check "lower field first", in my 3D app, otherwise it would flicker... Now, I know they used (before I get the job) Amiga, and Skala app to drive some static commercials, and animated stuff. Today, when I type in my Dpaint res 768*576 (on my Amiga 500, and fairly new crt TV), I got flicker. If I reduce it, I got flicker. Questions: 1) I thought that Amiga (on the go) supported Pal TV res. What is the max A500 res can support without flicker? 2) What is the native A500 res (if there's anything like that). Like res, in what the most games are done (talking about big titles like: Turrican, Ruff'n'Tumble, Shadow of the beast... etc). 3) I know that "flickerfixer" was inside A3000. So, I always thought that it would fix res flickering beyond pal (tv capabilities). Does it fix that? Can you display (with flicker fixer) 1280x720 res on a standard crt TV? And fourth question is never asked before, but: Was anyone else disappointed with the A1200?

21 August 2019, 22:51	#2306
demolition Unregistered User Join Date: Sep 2012 Location: Copenhagen / DK Age: 44 Posts: 4,190	PAL is interlaced so it flickers. All TV shows, commercials etc. had to be interlaced however if the two fields were not that different then the flicker would not be as noticeable. Amiga is almost PAL - the clock is slightly off but it is close enough so a TV would not mind. PAL has 625 lines, however only 576 of them carries video. With full overscan in PAL mode, Amiga should be able to show up to 566 lines as far as I can find (without overscan, PAL interlaced is 640x512). Most games run in low res which is 320x256 and typically only uses 200 of those 256 lines to make it easy to make both a PAL and an NTSC version of the same game (NTSC has fewer lines). A flickerfixer cannot be used with a regular TV. You need a VGA or multisync monitor to show a progressive (non-interlaced) image.

22 August 2019, 06:07	#2307
Magic Registered User Join Date: Aug 2007 Location: USA Posts: 365	Does a RTOS (real time operating system) exist for the Amiga?

22 August 2019, 13:58	#2309
d4rk3lf Registered User Join Date: Jul 2015 Location: Novi Sad, Serbia Posts: 1,693	Thanks Demolition. You are always of great help to us noobs.

24 August 2019, 19:49	#2312
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,910	Yeah, I guess with law abiding software it is possible to get that kind of performance. However there are no guarantees about anything given by AmigaOS and software can hog the whole system at any given time without the OS doing anything. :-)

03 September 2019, 15:48	#2314
Glen M Registered User Join Date: May 2017 Location: Belfast Posts: 750	Why is chip ram limited to 2mb? Since the A1200 has a chip ram expansion header that is unused is there any possibility of it being used even for fast ram? I understand the header is there because at one time the A1200 was going to ship with 1mb of ram allowing you to add the other 1mb later but why was the header fitted in factory? Makes me wonder if AGA was meant to have facility for more chipram but left out last minute because typical commodore. Wouldn't it be a laugh if there was some jumper undocumented somewhere hiding on our AGA machines to enable 4mb chipram (I know there isn't) And since I'm asking stupid questions... how does WinUAE make provision for up to 8mb of chip ram and would there be any possibility of a custom chip to make it work on the real machine?

03 September 2019, 16:57	#2315
demolition Unregistered User Join Date: Sep 2012 Location: Copenhagen / DK Age: 44 Posts: 4,190	The header is called a clock port because it is the place to add... an RTC. It cannot be used for fast RAM. And the header is not always fitted. Some motherboards have it, some don't.

03 September 2019, 19:36	#2316
CrazyPepsi Registered User Join Date: Jun 2019 Location: Sweden Posts: 66	here is one How did they make the music they cracked to the games the intros i mean

03 September 2019, 23:26	#2318
Daedalus Registered User Join Date: Jun 2009 Location: Dublin, then Glasgow Posts: 6,379	The custom chips are basically lacking the physical address lines to use more chip RAM. WinUAE doesn't have such physical constraints, so it's able to open up the addressing to a larger area. The Zorro-II expansion area is directly above the chip RAM area in the Amiga memory map, so chip RAM can in theory be extended into that area. As it stands however, RAM that's added in that area is classified as fast RAM because the chipset can't access it. To make the WinUAE method work on real hardware, you would need to replace the chipset (or at least some of the chips - Alice in particular), the bus / RAM controllers (Bridgette, Budgie), and some of the supporting logic and board traces. Doable, but it might be simpler to just use a Vampire, which is similar to WinUAE in that it side steps the physical limitations of the original chips.

01 October 2019, 19:06	#2319
matburton Registered User Join Date: Apr 2017 Location: Cambridge Posts: 136	OK here's mine Why 8 bits in a byte? So that makes sense to me for the 8-bit machine era. It looks like they typically had 8 data bus lines. But why have addresses which overlap data-wise on the Amiga when it has a 16-bit data bus? It seems even more strange when you consider that using 8-bit ops on the M68k sometimes need more cycles, and that you can't fetch unaligned words. Were there any computers in that era that bucked the 8-bit trend? Looking at the KS1.3 EXEC library it seems that most pointers are BPTRs, which point to a word. Does that mean that it wasn't clear whether an address per 8-bits was going to be a thing until late in development?

01 October 2019, 20:22	#2320
nogginthenog Amigan Join Date: Feb 2012 Location: London Posts: 1,317	It's only DOS that uses BPTRs due to its TripOS legacy (developed at the University of Cambridge BTW). EXEC doesn't use BPTRs as far as I know. If you're interested in TripOS and the Amiga Dr Tim King gave a nice speech at Amiga32. Probably on YouTube.

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