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For questions related to the Commodore Amiga family of personal computers.

3
votes
2answers
264 views

How were individual bit planes scrolled on the Amiga (OCS)?

Back in my early Amiga days (A500), I remember coding simple demos that would use the dual-playfield mode and scroll them around (at a sweet 60FPS). It was pretty trivial to do with languages like ...
1
vote
2answers
221 views

Commodore Amiga 600 Software Failure. “Error: 8000 0004 Task: 000026D0”

Software Failure on Commodore Amiga 600 when I insert a floppy in drive. Software Failure. Press left mouse button to continue. Error: 8000 0004 Task: 000026D0 Independent from the floppy I ...
7
votes
2answers
463 views

Were external floppy drives for Atari ST and Amiga inter-compatible?

Were external floppy drives for Atari ST and Amiga inter-compatible? For example, Commodore 1541* had its own serial bus protocol. But what about the external 3.5" DD floppy disk drive on 23pins D-...
6
votes
1answer
175 views

What did Commodore's AppShell and AppObject do?

Among the many developed but never released software that Commodore developed for the Amiga there should be two applications, called AppShell and AppObject. What were these? Did anyone ever saw or ...
15
votes
1answer
252 views

How to create a switchless multi-system 2 button Atari joystick?

All systems that use the Atari 9 pin joystick standard make use of the following pins in consistent ways, with each direction and the fire button being connected to the ground pin when pushed. 1 - up ...
13
votes
1answer
264 views

How do Amiga “Monitor” drivers work?

A "Monitor" driver for an Amiga is a file which, when placed in DEVS:Monitors, enables additional screenmodes. The standard PAL or NTSC driver, which provides screenmodes compatible with consumer TV ...
3
votes
0answers
104 views

Can't type angle bracket characters in AmigaOS 4.1 on WinUAE

Has anyone else experienced that when running AmigaOS 4.1 inside WinUAE that they can't type the < or > characters? I have a mostly bog-standard American QWERTY keyboard, no special emulation ...
8
votes
1answer
354 views

Why was Windows 3.1 so dreadfully slow on an Amiga A2286 bridgeboard?

Back in the day I had an Amiga 2500/30 with an A2286 as my "swiss army knife" home computer; not only did I have the ability to run MacOS (ShapeShifter) at native speed, but the 8MHz 286 bridgeboard ...
6
votes
1answer
182 views

How to integrate an 512kB EEPROM on a A3660 accelerator board at $00F00000?

I am currently experimenting with Chucky's re-engineered A3660 accelerator board for the Commodore Amiga (3000(T) and 4000(T)). My ultimate goal is to add an additional 512kB EEPROM to the ...
13
votes
3answers
1k views

How can you connect an Amiga 500/600/1000/2000 to a modern monitor?

I have an Amiga 500 that I'd like to get up and running again, but the 1084 monitor with which I used to use it has flyback transformer issues. What options are available to hook it up to a modern ...
4
votes
3answers
520 views

Amiga memory bandwidth

Looking at a timing diagram for the various kinds of memory access occurring on the Amiga http://amigadev.elowar.com/read/ADCD_2.1/Hardware_Manual_guide/node02D4.html it seems to be saying that video ...
19
votes
1answer
4k views

Why do all the Speech Synthesizers have that same Voice?

The first time I ever played with software speech synthesis on a microcomputer (not hardware synthesis, like in TI's Speak & Spell) was around 1983, using S.A.M for the Commodore 64. A year later,...
4
votes
1answer
195 views

Identify this Amiga game: It's just like Rocket League

I remember playing an Amiga game which was very similar to Rocket League, subject to the technology of the time. It was a two player game with a top-down 2D playing area. There was a large puck ...
7
votes
2answers
126 views

Question about external Gary NAND driving _BLIT in depency of _ROMEN

what is the meaning of the NAND external connected driving _BLIT in depency of _ROMEN? I cant see the need mainipulate _BLIT by accessing the ROM. Is this an Gary bugfix? Strangely A500+ does not have ...
4
votes
1answer
148 views

Amiga ed removes flags

Recently I noticed a strange behavior when editing startup-sequence with ED. Unless I call protect startup-sequence rwed before editing it, ed says unable to write the file. Saving the file ...
6
votes
1answer
155 views

How do specify drives to mount when Amiga 1200 starts up

I have an Amiga 1200 with an SD card and Classic WB installed. I have four drives DH0, DH1, DH2, DH3, when I start the machine with workbench it mounts all devices. If if start the machine using skip ...
0
votes
1answer
232 views

Amiga 500+ does not start up [closed]

Amiga 500+ does not start up. It has been offline for a considerable amount of time. The machine powers up but does not move from that point. I have inserted the workbench disk. Can anyone advise the ...
9
votes
1answer
189 views

When did Great Valley Products, stop producing hardware?

I had a GVP 68040 card in my old Amiga 2000 (ah those were the days). 25Mhz 68040, 16MB of RAM, SCSI controller to my 750 MB SCSI drive (if that was even 3200rpm I was probably lucky) and it was SO ...
0
votes
0answers
63 views

WinUAE, create a hard disk image of only boot partition?

If I have my CF Card connected in WinUAE, I am only able to create a hard disk image of the full 8GB. Is it possible to only image the boot partition? Thanks
5
votes
2answers
245 views

How to create fast an icon file for Amiga program in WB drawer?

I have copied one program from a floppy to a hdd drawer (I created for it) and I want to start this program directly, without going through Window -> Show -> All Files first in my Amiga ...
5
votes
1answer
214 views

Should I start Amiga's copper list using COPJMP1 or is it superfluous?

According to the documentation I have ("Hardware" by J.Schimanski) after setting the copper list COP1LCx under $dff080 it should be started by writing an arbitrary value into COPJMP1 under $dff088. ...
9
votes
2answers
246 views

Version Control for AmigaOS 3.1

I owe my career as a software developer to the Amiga. I might have learned the basics of programming on the Apple II+ and Commodore 64 - but on my Amiga I learned skills I've applied to my whole ...
6
votes
1answer
172 views

What is the necessity of the Signal BLS (Blitter SLow)

I am trying to understand the Amiga schematics: Question 1: What is the necessity of the Signal BLS (Blitter SLow) generated by A2000A U26 or Gary in the A2000B? Question 2: BLS is also set by ...
5
votes
2answers
353 views

Transistor count of copper and blitter

According to https://en.wikipedia.org/wiki/MOS_Technology_Agnus the Agnus, one of the three custom chips in the Amiga, that included the copper and blitter among other functions, contained a total of ...
6
votes
1answer
385 views

Start application after Amiga Workbench 1.3 boot sequence

I want to start an application after the boot sequence of Workbench1.3: In my case an Amiga Shell application: Where are the startup files located and what are the changes to provide this?
4
votes
2answers
498 views

How hard would it be to port Amiga OS4 to x86 or ARM?

This question was raised on Facebook a few hours ago. Some say it's possible, others say impossible. What do you experts say?
12
votes
1answer
363 views

Where are the blueprints of MOS chips?

Atari historians have been able to find documents and tapes of chips and hardware developed at Atari. E.g. http://atariage.com/forums/topic/154479-new-gtia-chips/ . Nothing like this is happening ...
14
votes
2answers
951 views

Creating a new language support for AmigaOS

Looking through the LO (localisation) disk for Workbench 3.1, I see that the language files are binary. I'd like to create a Gaeilge (Irish) localisation file. How is this done on Amiga? Update: ...
11
votes
2answers
335 views

What interface did Video Backup System use?

I remember the Video Backup System for Amiga advertized in Polish computer magazines of late 90s, "store hundreds of diskettes on a single VHS tape!" I seriously considered buying it (and a VCR since ...
9
votes
1answer
216 views

What was the difference between the original Video Toaster and the 4000 version?

There were two versions of the Video Toaster hardware: an original one designed for the A2000 and a later one designed for the A4000 which was suitably called the Video Toaster 4000. While I can ...
7
votes
2answers
317 views

Amiga Video Toaster support

What features of the Amiga chipset architecture and/or Amiga OS made it possible to design the Video Toaster run on the Amiga? Why weren't there similar (cost-effective) video products for the PC or ...
10
votes
1answer
332 views

What is the relationship between Amiga audio and the MOD music file format?

What is the the MOD music file format? Exactly how does it relate to the Amiga 1000 audio hardware? Did the MOD format become popular on non-Amiga computers? If so, why?
18
votes
7answers
2k views

Was Amiga the last of the home retrocomputers sold?

The Commodore-Amiga was offered for sale to home users from 1985 (original A1000 in North America) until 1996, when Escom stopped selling the A1200. By 1996, Apple was selling PowerPC-based Macs for ...
12
votes
2answers
396 views

What's the meaning of __saveds in Amiga C code?

What's the meaning of __saveds in Amiga C code? It's applied to function prototypes, and is required for functions that are to be called by assembler code, if I understand correctly.
9
votes
2answers
235 views

How many gates does each chip in OCS have?

According to Wikipedia, the original Agnus has 21000 transistors. How many gates would this be? (assuming there's a straightforward way to convert between gates and transistors). What about Denise, ...
10
votes
3answers
719 views

Can artifact color mode create 262,144 colors on Amiga OCS?

This is as a follow-up to my previous question on artifact colors and the excellent answers provided there. The images below show a simple example of artifact colors generated using a single bit-...
10
votes
2answers
271 views

Why was OCS low resolution limited to 6 bitplanes?

I'm looking for information whether there has ever been an official statement by Commodore back in the days on why the Original Chipset was limited to doing 6 bitplanes only when running in low ...
10
votes
3answers
765 views

Is it possible to expand Amiga 500 rev 8 to 1.5 MB with a 1MB trapdoor expansion?

Is it possible to expand an Amiga 500 rev 8 (not an Amiga 500 plus) to 1.5 MB of Chip RAM using an A501+ expansion? It is plug and play or are modifications required? The board is this http://www....
15
votes
2answers
902 views

How does the Kickstart ROM load and start workbench?

As I understand, on the Commodore Amigas, the kickstart copies itself into a region of memory which is later made read-only. Does kickstart also copy workbench into this region? How does kickstart ...
17
votes
1answer
1k views

Was it possible to get more than 8 sprites per scanline on an Amiga with the copper list?

I've read in the past that it was possible to overcome the 8 sprites per scanline on the Amiga (OCS) using the copper list. However, I can't seem to find any actual references to what may have used ...
10
votes
3answers
227 views

Will using a clockport RTC card on an Amiga 1200 clash with the RTC on an accelerator card?

I have an accelerator card fitted to my Amiga 1200. The accelerator includes a real-time clock, but I noticed that the soldered-on rechargeable battery was in danger of leaking, so I cut it off before ...
11
votes
2answers
454 views

How does the Amiga chipset RGA bus work?

The RGA bus is the bus that connects Agnus/Alice with Denise/Lisa and Paula. What is it used for? I guess at a minimum to write/read registers in Denise/Lisa and Paula, and I guess to feed data to ...
13
votes
2answers
476 views

What was exactly the Amiga Ranger?

Amiga's history includes something called "Ranger" that supposedly was either meant to be the next generation system to be released after the Amiga 1000 was released, or the codename for the next ...
19
votes
3answers
1k views

Why does MP3 audio decoding overwhelm retro CPU's?

Many retrocomputers from the late 80s and early 90s had audio DAC hardware support. This includes the Amiga, Classic Macintosh, and PC's with SoundBlaster add-on cards. Despite the fact that the MP3 ...
11
votes
2answers
266 views

What happens when a floppy track contains multiple sync words?

This question is specifically aimed to the Amiga hardware. Let's assume a floppy track is read via DMA using sync word to trigger the start. Let's also assume the track contains the sync word ...
8
votes
2answers
1k views

Amiga-looking keyboard for PC

I would like to use an Amiga-looking keyboard on my PC. (I prefer not to use my old original A2000 keyboard with an adapter, partly because it lacks many keys present on modern 105-key keyboards, and ...
12
votes
1answer
286 views

What are all the fixed addresses of AmigaOS?

I was reading Richard Downer's excellent response about how Amiga libraries work and one sentence in particular got my attention: Yes, a pointer to exec.library is always at $4, and this is (in ...
24
votes
1answer
713 views

How did the Amiga DCTV work

This is an unusual question since I'll answer it right away because it was a truly unique device and there is absolutely nothing about the technology it used on the internet. I spoke with the hardware ...
17
votes
2answers
775 views

How are Amiga libraries structured?

In this Crash course to Amiga assembly programming, the author loads A6 with a constant, and then regularly jumps to offsets from that constant. He explains: All functions within that library can be ...
53
votes
6answers
6k views

Reason for the Amiga clock speed

The Amiga used a CPU rated for 8 megahertz, but clocked at 7.14 megahertz. What was the reason for this number? I remember it was something to do with a multiple of the frequency of the video ...