Amiga Hardware Ideas

This is now completely obsolete but I've left it here as it contains quite a few ideas some of which may still be relevant.
N.B. 28th November 1998

After placing my last set of designs on the web I had some comments from Dave Haynie which I kept in mind when I decided to redesign them.  I then sent the new designs to the head of Gateway 2000 to see what they thought in early June 1997. I didn't get any response unfortunately so rather than leaving my designs sitting around my Hard Disc I'm now placing them on the Web.

Differences
The differences I made were mainly to cut cost down, I cut out a great deal of stuff which would cost a great deal to design and make and replaced these with more standard components.  There was one completely custom chip for graphics and I changed this as well.  Rather than going for a complete off-the-shelf approach I have in these designs used a partial custom design which would use existing components as well as some custom designed areas, an example of this would be the 3D graphics unit which would be brought in from another company, only those areas which would need to be specially designed would be.

The previous designs also used a dual processor system which I removed and used a single processor instead.  There is however a second small CPU on board the partial custom chip to control various aspects of the system.

Potential Amiga Designs

5th June 1997

© Nicholas Blachford 1994-1997

A range of high performance modern Amigas based on modern technology designed to be the best in their respective markets and provide systems that could also embrace other untapped markets. Includes a number of ideas designed to improve performance and create better, more efficient systems. Custom hardware is used very little and only where appropriate producing both high performance and low cost.
Includes diagrams A2302, A2402, A5102, A6102 and A4chip.
 

In the accompanying pictures I have drawn a series of designs of potential Amiga type computers. They are based around a PowerPC or DEC Alpha CPU and a powerful partial custom chip called the A4. Additional chips would also feature but most if not all would be standard off the shelf components.

I can see no point in directly competing with PCs, the Amiga has never been a PC. While there may be machines at a similar price range the aim would be to target these machines at specific markets and anything picked up from the PC market would be a bonus. The four machines I have designed are designed for the home entertainment market, the video and computer graphics market and as a side the computer music market. The diagrams are as follows:

A2402

This is the replacement for the A1200, lower A4000s and forms the basis of the entire range. It is based around a PowerPC CPU and a lower end version of the A4 called the A4L. The remaining components will all be standard off the shelf parts with the possible exception of one bus controller. Rather than an expansion port PCI slots can be included but these may not be included in some versions. As with all models there is a choice of internal modem or ISDN connection, the modem would be included in UK and US models but switched for ISDN on other European models. There is no standard Hard Disc on the A2402 but a Zip drive could be included in some models as well as the standard CD and floppy. The entire AmigaOS would be included in a large system ROM. This would replace A1200 type machines but may come in at a slightly higher price.

A2302

This would be best thought of as a games console with a keyboard & floppy disc. It would be used for games or for accessing the Internet but it could also be used as a multimedia playback device like the CD32 or CDTV. The price could be kept reasonably low as many components have been cut out. A low cost CD ROM drive is included, as is a floppy drive. The system uses the same graphics system as the A2402 but there is no bus controller and a lower end PowerPC could be used. There are also no PCI slots but some form of expansion slot could be included.

AmigaStation A5102

This would be a replacement for the Amiga A4000. It is an enhanced version of the A2402 offering both FireWire and Ultra SCSI as standard. There are 8 PCI slots as opposed to the 4 in the A2402 and up to 4 of these will be the faster PCI 2 slots. This machine will come with a standard Hard Disc so the ROM can be smaller. The biggest difference by far will be the use of the full A4 chip, which will offer 2 video outs as standard and resolutions up to 2000 by 3000 in 24 bit colour when sufficient memory is fitted. This machine would be sold to advanced home and business users and especially the video industry.

AmigaStation A6102

This would be the top of the range Amiga commanding a workstation type price and delivering workstation level performance. The CPU is most likely to be a high end Alpha. Although this is based on the A5102 the biggest difference is the addition of an addition of six PCI 2 slots. These would be used to connect additional CPU boards and would all be able to run concurrently allowing very high speed transfers into System or Graphics memory. This system would act more like a group of individual computers instead of one big computer, each CPU would have it’s own RAM but would be able to write to system or graphics RAM via the bus controller.

I envisage this machine would be sold into the Video and Movie industries and especially for graphics rendering. Although the A5102 would be capable of the same resolutions it is likely that only the A6102 fitted with several extra CPUs would be capable of animating this resolution at anything like full motion video. One application, which would require the high video bandwidth, is movie editing where resolutions are in the order of at 2000 by 3000 in 24 bit colour at 25 Frames per second.

Other Designs

I have not drawn any diagrams for these but here are some basic descriptions for some further designs also based on the A2402 architecture:

A2202

This is an even lower end version based on the A2302 but with no CPU. Instead the internal Embedded CPU on board the A4L would be used as the system CPU. This could operate out of the system bus or alternatively an even lower cost version of the A4 could be developed which did not have all the separate busses. This would give lower performance but would allow the chip into much lower cost applications.

Amiga TV

It would be possible to use the above Amiga designs as the basis of an Amiga based television. The capabilities of the A4 would mean that all the facilities of high end TV’s could be included for no extra other than the cost of the screen and the electronics for it. This TV would be the most feature rich TV ever produced combining a computer, games console, Internet access and DVD playback all in one unit. The massive video bandwidth of the A4 would allow it to handle the TV images without any problems.

The only problem I can see with this unit is that as a few years passes the first units will eventually go out of date and will not be supported by software companies. The solution I can see for this however is to make it possible to upgrade the unit in service. The best way to do this is put the A2402 on a replaceable card or add some form of expansion slot where a user can plug in a card with a better CPU / graphics chip. This way the unit can remain in service for many years as TV’s tend to.

Computer / TV combinations have been tried before but have yet to be very successful. The problem in my view is that a good PC cost a lot of money and adding a TV to this only costs more putting it well above the price of most TVs. Another problem is that TVs last years whereas even the newest computers are out of date within months. The Amiga TV would cost no more than a good TV set and also be upgradeable removing at least the cost and obsolescence problems of TV-Computer combinations.

A4 based PCI cards

To increase the manufacturing volume of the A4 partial custom chip it could be used on a PCI or AGP based graphics card for PC’s. Both the A4 and A4L could both be used on cards and the I/O bus could be used to provide sound and other functions all on one card. This card could even be sold to other PC or Amiga manufacturers.

Bus Systems

To allow for the most efficient operation many of the function units in the A4 would be on separate internal bus systems. For instance the I/O bus and Embedded CPU would be able to function quite independently on a bus completely isolated from the graphics bus. The video output unit would also be able to send signals to the MEPG Encoder directly and it would be able to write data onto the system bus without interfering with the rest of the graphics system.

Although this may seem like a minor aspect, it is one of the main methods I have stuck to in both the internal bus systems and the external bus systems. Isolating the I/O components on their own bus system simplifies the system bus and leaves the CPU to continue processing rather than requiring the CPU to stop and do something else. The Bus Controller in the A2402 and upwards is to allow data to be transferred from the PCI bus to the A4 also without interfering with CPU access to RAM.

A4 Custom Graphics chip

This is a new partial custom chip to replace the existing Amiga chip set, it would not however be compatible with the existing chip set. It will come in two versions, the full A4 and the lower cost A4L. There would be little internal difference but the 3 main bus systems are 128 bit on the A4 and 64 bit on the A4L, the I/O bus is the same on both. The A4 is designed primarily for graphics but it also includes a music synthesiser and an embedded CPU which controls the Input / Output bus for the system. These are only low bandwidth applications and do not use the Graphics busses. They are likely to have minimal impact on the graphics performance of the chip.

The A4 is designed to ring the maximum performance out of the system, in fact it does most of the work in the system pretty much leaving the CPU to do it’s own thing. On the machines with the system bus controller they work together so the A4 can read at full speed directly from the PCI bus without effecting the CPU bus. The system could be playing back an MPEG movie direct from disc and the main CPU could switch itself off.

The A4 is also unusual in that it can also read direct from system memory although this would involve locking the CPU out. This facility would allow the A4 to scroll through very large images at high speed without involving the CPU in the operation. The A4 may even be capable of display images direct from system memory but this is unlikely to be used in most systems other than low end versions which may not have separate bus systems.

A4 Graphics Busses

As well as the connection to the main system (CPU) bus there are two dedicated Graphics busses on the A4. This is where the speed of the A4 would come from. Normally Graphics are stored in a single memory and reads and writes are both done from there. This of course causes contention between the reading and writing sections as they fight for control of the bus but it can be reduced by using expensive VRAM.

To get around this problem the A4 uses two graphics busses, one for reading, and the other for writing. When the writing is complete the two busses switch over reversing the process. These busses do not require any expensive VRAM but can use normal cheap SDRAM. This system uses large 128 bit busses to provide very high bandwidth allowing both very high resolution displays and by using dual busses even the highest resolutions can be fully updated on every frame.

By using this system workstation type resolutions can be achieved on the Amiga for a much reduced cost. While this in itself may not be that useful the additional bandwidth will be very useful at lower resolutions for video manipulation and 3D Graphics. In addition to this there is a special 24 bit data encoding and decoding system that increases bandwidth by a further 25%, this system also decreases memory usage by the same amount.

Giving the Amiga such a high bandwidth video system and direct connection to the system bus means that unlike other systems it will take a very long time to go out of date. It also allows additional CPUs or 3D Graphics chips to generate imagery faster then the A4 internally yet it would still be displayed on the A4 at full speed. This fact is used in the A6102 to allow the display of full frame movies even thought the MPEG decoder on board the A4 would not be capable of decoding such large images.

It would be possible to provide similar performance with a single 256 bit video bus but this would be a lot more complicated and would in fact be slower. This type of bus would be constantly be switching between reading and writing data and this would incur delays in the SDRAM. If a single 256 bit bus was used the video resolutions possible with SDRAM would be significantly lower. The dual bus system would allow for longer reads and writes and consequently less delays on the bus allowing much higher resolutions to be displayed.

Video Generation and Manipulation

The Amiga has always been used for video work and the additional bandwidth will allow the A4 to read in several images at once and combine them together using the Image constructor. The A4 can also operate as a display list based system so images can be moved relative to one another with only a few basic instructions. As well as moving images and combining them together the system would also be capable of manipulating graphics directly using the Digital Signal Processor and Graphics Processor.

To generate images the 2D and 3D graphics units can be used and the MPEG unit can decode data streams from disc. Additionally data can be directly transferred from the system bus (see above).

The full A4 can give two simultaneous video outputs, one could be used on a normal computer monitor to control the output while the other could be on a television type screen or a very high resolution screen. This allows the user to be able to see and control what is being displayed, the main output may be going to video tape and viewing the display directly may reduce it’s quality.

The A4 would also include a Video Digitiser which should be capable of digitising computer displays, not just TV. It should also be capable of digitising HDTV signals so the system could be used to manipulate them. Most video equipment would be no use whatsoever when HDTV equipment finally arrives so adding a high speed digitiser would provide a foot into a market before it even exists!

Other functions

For the Embedded CPU something like an ARM might do as these are physically small chips. It will not be dealing with Graphics directly as it will be sent around on large dedicated busses but the embedded CPU will be required to read and write data destined for the I/O bus. It will also be able to read from the main system bus but only via the system bus controller. The OS will access the functions of the A4 via the embedded CPU. Instead of allowing programmers to hit the hardware directly programmers will talk to the Embedded CPU and it will send commands to the various function units on board the A4. In the A2202 the Embedded CPU takes over as the main CPU so it must also be capable of acting as one of these.

Some programs may not like double buffered video as it requires everything to be drawn twice, to solve this a copy back mechanism could be included so when data is read from one buffer it is written into the other buffer.

I have devised a way whereby it would be possible to produce a Virtual Reality display using a single LCD, I have added a port labelled VR in several of my designs for this purpose.

Partial Custom Design

The A4 would only be a partial custom design. There would have to be a great deal of design work done on it but there are some sections which could be licensed from other manufacturers.

These sections would be:

There are chips which already do most if not all of these functions and it may be possible to use one of these as a core for the A4 but there will still be functions which will have to be custom designed: Audio Output

The Amiga would have good a very good start in the music industry if it was not for the Atari ST including MIDI ports as standard. I consider that this would be a good market to chase as no other major computer company seems interested in it. To this end the A4 would include a 32 or 64 channels audio synthesizer. The sound chip on the I/O bus would be a minimum 16 bit device with good quality analogue and digital input and output. In the diagrams I have included a high quality General Midi ROM which would certainly help porting PC games but would mean the Amiga could also be used as a musical instrument without additional hardware and minimal software. The audio system would only use the GM ROM as a base for some sounds but would store all other sound data in system memory.

I would include MIDI ports to interface with keyboards and other audio equipment. One problem that needs sorting out is that of timing, one of the reason the Atari remains popular to this day is the fact that the timing is so solid. Amigas, PCs and Macs all drift and this can be a problem for professionals. Audio seems a natural market for the Amiga to go into given it’s connection with video and what I have suggested is nothing more than a decent PC will have with two exceptions. Firstly is the timing problem but also is the fact that the audio output of even the best general purpose sound cards is generally not very good.

Choice of Processors

For these machines I have chosen two processors. The Alpha was chosen simply because it’s speed. One of the Amigas main markets is in 3D graphics rendering, for this a processor is required with the maximum computing power within a reasonable price margin. The only chips which can do this are the Alpha and the PA RISC. While the Alpha has been overtaken speed wise in the past there is usually a new faster Alpha which arrives shortly afterwards, DEC is also rather more open than HP when selling their chips. For the low end I have chosen the PowerPC which would provide high speed along with reasonable cost. For the mid range machines there would be a choice between the Alpha-PC chips and the PowerPC.

The Embedded CPU for the A4 would have to be looked at but I suspect something like the ARM or possibly StrongARM may be useful for this purpose as both are small chips. The DSP on the A4 is a different matter altogether as it’s main purpose in life is to manipulate graphics data at high speed so it should be suited for this. It may also be used at times for adding effects to audio data although the Embedded CPU could also do this if fast enough.

Standard Components

The Amiga has always tended to use custom built components, this is very beneficial if you are talking about the custom chips but using custom keyboards, mouse or even ports is only adding to the cost of the system. For this reason I would only use custom hardware where it would provide a benefit, the A4 would be the only custom chip in the system and most of it would probably be licensed. The remaining components would all be standard PC components. Nearly all the standard Amiga ports could be changed or replaced with something like the new USB. Only the Video port would really be of much use since keeping it would retain compatibility with a great deal of existing hardware and allows the connection of Genlocks and other video equipment. The expansion bus system would be the PCI bus (preferably the 64 bit PCI 2). I would have considered custom connections for the CPU cards but even these could be managed using 66MHz PCI 2 connections.

 Custom Function Units

Most of the A4 could be licensed from chip manufacturers and the rest could be designed by a manufacturer under instruction. Preferably one with experience of high bus speeds. These units are as follows.

System and Graphics bus controllers – These units would drive the high speed 128 bit bus systems which should work at 100MHz or as close as possible, higher frequencies would be used if possible.

The 24 Bit System – The 24 Bit system is a means by which the video bandwidth of the system can be increased by 25%. Normally you would write 4 bytes (32 bits) at a time since this is considerably easier to read and write. You could use 3 bytes (24 bits) but this is more difficult to manipulate and address and would probably end up slower then using 4 bytes. The 24 bit system uses hardware to pack 4 bytes into 3 bytes and encoding the addresses. This has the effect that the system thinks it’s working with easy to use 4 bytes but is in fact only using 3 bytes. This system involves very little encoding / decoding hardware other then a few buffers but allows data to be read and written 25% faster than using 4 bytes and uses 25% less memory. There are disadvantages to this since writing an individual pixel becomes slower but writing a block of data becomes faster.

Display List Processor – Using a display list allows graphical operations to be carried out using only a few instructions whereas they may normally require a great deal of data to be moved. An example of this is moving a window where the window would usually have to be picked up and moved and the background redrawn where it has been moved from. With a display list the window would never be physically drawn over the background, instead when the window is meant to be drawn the display buffer would start reading from the location of the window instead of the location of the background. No data would actually be moved so moving a window would become a perfectly smooth operation. The DLP could also be used to generate some video effects such as shaking or waves, these are however only the beginning of what could be done with the DLP.

Image Constructor – This takes in a two or more images and merges them into a single image. This merging could be simply displaying one image in front of the other or perhaps fading one image into the other. It also has to cope with different resolutions and colour depths and display them all as true colour. The image constructor could mask (Key) images so some parts appear while other parts of a selected colour do not. An example of the types of work the Image Constructor would be capable of would be a News presenter. The background would include an image from the story which would appear to be placed behind the presenter. In front of the presenter subtitles could appear and a channel logo could appear in front of everything in the corner possibly faded with the main image. This unit may also do some other operations on individual images such as reversing them or flipping them upside down.

Image Post Processor – This unit is placed after the Image Constructor and does operations on the entire image. These could include arithmetic operations on the RGB data increasing or decreasing the level of Red, Green, Blue or overall brightness. The Image Post Processor would also be able to manipulate the RGB data creating some unusual colour effects, even giving a monochrome or tinted output. To get the best out of this unit it would be necessary to use a higher colour DAC than usual giving the output as 36 bit colour. The image post processor would also be responsible for smoothing the image output and by skipping or adding pixels or lines some unusual effects could be generated.

Sprite Generator – Sprites are images added in front of the image on screen. An example is that of the mouse pointer. PC’s generally draw these even though the hardware in many cases supports them. Drawing the mouse pointer makes for a much more jumpy pointer whereas the Amiga using a sprite is much smoother. The resolution of the sprite can be changed to allow it to remain visible on high resolution screens.

Colour Graduation Generator – This is a means of adding a smooth colour graduated background but without having to draw it. The hardware for this consists of a number of registers along with a few adders. This system could generate a graduated background even when the system was not reading any data from graphics memory. Changing the values in the registers would allow for graduations which change colour, move and even reverse part way down the screen.

Anti Piracy System – This is not so much a function unit but more of a small ROM which would not normally be accessible. This feature would be used for some programs (most likely games) on CD which could not be installed. The ROM would include code which checks the CD ROM to make sure it is exactly as it should be, if not the program will refuse to run. The ROM would also prevent any access to the system while the checking is in progress so as to prevent hackers from trying to access the ROM. If an unauthorised access occurred the ROM would do all possible to prevent any data being read. This may involve clearing all memory and even purposely putting errors on hard discs, this last option may be a little over the top but the codes must NOT become public. Data could be encoded by Amiga International itself to avoid any codes having to be given out.

Conclusion

My designs may seem over the top with the high end systems providing a potential 3.2 Gigabytes per second graphics bandwidth, 1.6 Gigabytes per second system memory bandwidth and the option of multiple CPU cards. However, similar systems already exist and command a positively fear inducing price tag. My systems would produce a very powerful computer system capable of editing motion picture grade images at a never before seen price/performance level. Disney’s Toy Story took 300 Sun workstations to do the rendering whereas only a few fully expanded A6102s would provide the same processing power for less than one tenth of the cost. What’s more this system would also be capable of playing back and editing the images in their full glory.

This is only the high end system but even the medium range machine may also seem over the top with the same graphics system. This my be so but this would up against some pretty fierce competition including everything from alternative Amiga manufacturers right up to Silicon Graphics workstations and down to the ubiquitous PC and increasing numbers of Power Macs. Then of course is the development time which means the A5102 wouldn’t be ready for a couple of years by which time everyone else’s specification will have improved anyway. The Amiga needs to stand out from the crowd to be noticed and I advocate a heavy push into the video market where the Amiga already has a good foothold. Add a few video inputs on a card and the A5102 could do everything Newtek’s Video Toaster and the Video Flyer is capable of.

At the low end is the A2402 which includes quite a number of features which would normally have to added separately and are not included in any basic PC or games console. Such a system would go directly into the existing home computer market all be it at a higher price point than the A1200, apart from some very low end PCs there is still no direct competition at this level despite the absence of the A1200. I see no point in directly competing with PC or consoles so the best method would be give the graphics power of a console, the versatility of a PC and the low cost of an Amiga. The additional components would give the Amiga more capabilities than any PC anywhere near that price point.

At the very low end is the A2302 which is pretty much a cut down A2402 with a lower price tag. The system would be competing against consoles but by providing an internal modem along with a keyboard and floppy drive would provide the lowest cost route onto the Internet as well as a means to save users downloaded data. This system would also provide a very good set top box or Network computer.

My designs may seem excessive in some places but the Amiga started by providing a system which was graphically better than any other. For the Amiga to get ahead again and get into the other markets where it would be perfectly suited it again needs to be ahead. By working in conjunction with other companies the A4 could be developed without excessive costs and it could then go on to provide workstation level performance at PC prices – or even below.

An Example

The AmigaStation A5102 TV studio in a box.

With the power of the A5102 it would be capable of doing a great deal of work with very little in the form of additional hardware, an example of this would be managing a TV studio.

With an multiple video/audio digitiser card added the system could accept the inputs from quite a number of cameras and video playback devices, these would be fed into the 1st graphics memory block and if necessary effects applied to them.

Using the A4s dual outputs the director could see miniature versions of all the inputs on a single hires control screen while the main output would go out to the audience. The director would use the control screen to pick each output as and when required. In addition to this the main output could be fed back to the MPEG Encoder and stored on disc.

None of this would use the PowerPC / Alpha CPU much so it would be free to create animations and overlays in real time and write the data into the first graphics memory block as another video source. The CPU could also use the 3D hardware in the A4 producing high quality 3D animations.

You could probably build a system like this today using the Amiga and Video Toaster / Lightwave / Flyer systems but it wouldn’t be able to handle even nearly as many inputs and most certainly would not be capable of doing it all in a single Amiga using only one additional card. The AmigaStation A5102 would do an awful lot more work for a lot less money.


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