Quote
"I remember being fairly rude about a number of mistakes they'd made in the design. It could have been so much better with a couple of tiny changes that wouldn't have cost anything at all. Gah..."
Any idea what these mistakes might have been?
Who and where was the quote from?
From this article Face-Off: ZX Spectrum vs. Commodore 64 • Eurogamer.net (http://www.eurogamer.net/articles/digitalfoundry-face-off-zx-spectrum-vs-commodore-64)
concerning the CPC, to me :
=should have had more than 64K to begin with... would need quite some extra chips but 80K or 96K (if not 128K) could have changed the whole speccy port things.
Speccy48 ported into CPC464 : can't get properly Amstrad Graphics (2x more heavy) and issue with proper AY sounds sometimes.
only 16k or 32k more could have been quite enough to get most of those ports done quite betterly.
=some say the AY soundchip could have been implemented a bit betterly.
=technology used may not enable it, but I would add 5 custom colours to the palette to have it properly 32 colours.
would add : Dark grey, Light Grey, dark Orange, Dark Lime and Dark SeaGreen (2 greys + darker versions of the 3 hybrid colours including green/yellow in them)
yeah yeah, better scrolling, hardsprites, Blitter, VGA graphics and soundblaster and overclocked 16mhz Z80 as well... ;D
Graphically, some sort of optional colour attribute yet still using the Amstrad video modes would have been killer...
Most other computer woudl not have more than 2 colours per attribute unless large pixels.
Mode1 with soem attributes so you could choose from 4 palettes (the 16 colours from the Mode0), or Mode2 with speccy like attributes (well, Mode2 sized characters of course)...
No real need to rasters then : just use the attributes. Mode1 would then be killer look.
anyway, mostly the ideal Amstrad 8bit would have been some mix between CPC and PCW indeed.
Nothing. It was frickin' awesome and I will beat the crap out of anyone who says otherwise. Especially MacDeath. 8)
* The low quality built-in speaker.
* the memory layout of the screen - every 8-lines
* the hardwarescrolling could have been better
* hardwaresprites
* no fast charactermode
* no low-memory screen-modes
* not an option to buy it cheap without a monitor
* the external modulator was low quality
* quick and dirty spectrumports
* the high sharpedged keyboard
I was about to say the screen memory layout also, this could have been fixed just by rewiring the way the CRTC lines are connected to the Gate Array in a "sane" way, this would have been a tiny cost-less change.
About that, it's curious, because the way it is arranged could be useful for faster text priting if it were done in a line-per-line basis. But the firmware finally came with character-by-character printing routines, so the weird layout has no advantage. It seems like if they had planned to do it a certain way and later, when the hardware was already in production, they changed their mind.
Quoteanyway, mostly the ideal Amstrad 8bit would have been some mix between CPC and PCW indeed.
You mean the PcW16? ;D
True, we don't talk about "brand new graphics modes and SID sound and stuff", but little things in the design you wonder why they have done it like this. I have read that quote on the article and laughed about how the amstrad designers thought the guy tampered the hardware, but I was very curious to hear exactly his opinions on which were the mistakes. Did they make it like this because of costs or as he says they could be easily fixed?
The video memory map is obvious wtf. But it was similar in spectrum. Most 8bit machines didn't have a linear way.
But for me how the pixel bits are interleaved in mode 1 or 0 is puzzling. Ok, I know you can shift the bits to move pixel to near side in one byte, but why mode 1 has the 4 bits not in order?
And the palette values to color are so weird.
A lot of stuff on the CPC is weird.
Also, what I recently learned and was laughing out loud was, the CPC OUT (C),r is not canon for Z80. it should out register r to port in reg C. But no, it outs to port in reg B. Whaaaat? I mean, I knew this since I was using, but I thought it was a quirk of every Z80 chip itself, not the CPC bad wiring. Also, I think out (C),0 is problematic on CPC?
Such things I am curious to hear about (and I guess the original quote meaned), not if the CPC should have special hardware sprites, tile mode and such.
maybe turn the question around what was so great about the CPC?
or what was wrong with the C64 and Spectrum?
The BBC B was just all round good....
Quote from: MacDeath on 23:43, 04 November 14
concerning the CPC, to me :
=should have had more than 64K to begin with... would need quite some extra chips but 80K or 96K (if not 128K) could have changed the whole speccy port things.
It was designed in 1983. Memory wasn't cheap and at that time 64k was huge. Competing micros had far less.
People say it should have had X, Y or Z but these things are set in stone long before machines hit the market.
You only have to look at what happened with the Enterprise to see what problems a long feature list caused. That machine crashed and burned. Amstrad had enough problems with their own gate array!
Quote from: dcdrac on 13:36, 05 November 14
The BBC B was just all round good....
Awful graphics, a ludicrously high price, a speaker that played awful music with no volume control capped off with a total lack of support from the big publishers.
Quote from: Optimus on 13:27, 05 November 14
The video memory map is obvious wtf. But it was similar in spectrum. Most 8bit machines didn't have a linear way.
I can't remember why the Spectrum had that display, it may have been something to do with RAM refreshing. If they did it that way the ram was refreshed without needing external hardware and so they could cut costs.
On the BBC, the memory map is a little different to CPCs. Same CRTC, different decoding of the addresses.
It is arranged as so:
byte 0, byte 8, byte 16...
byte 1, byte 9, byte 17...
byte 2, byte 10, byte 18...
to get this they re-arranged how RA/MA makes memory address from CRTC.
Quote from: Optimus on 13:27, 05 November 14
But for me how the pixel bits are interleaved in mode 1 or 0 is puzzling. Ok, I know you can shift the bits to move pixel to near side in one byte, but why mode 1 has the 4 bits not in order?
I believe for simplicity of hardware design.
BBC shares a similar design.
The data is loaded into a "shifter". It's a temporary register that holds the byte data while the video hardware uses it. The shift rate depends on the mode. But each time a shift happens it moves the bits 1 place to the left.
Bits 7,5,3,1 are always read out for simplicity and are used to form pen index.
The pen index is configured so bit 7 becomes bit 0 of pen index.
bit 3 becomes bit 1 of pen index.
now you can then choose how 5 and 1 are setup for mode 0.
If you put the same bits in the same places it's more simple for hardware design.
Bit 5 and 1 can be interchanged. Amstrad chose one arrangement, I think BBC chose the other.
Once the pen index is extracted, it is ANDed depending on the mode.
e.g. 0x01 for mode 2, 0x03 for mode 1 and 0x0f for mode 2.
So all modes are constructed from the same bits that are extracted and in the same position but different mask is used to get the pen.
But the main reason the bits are interleaved is so that the shifter can move the next pixel into position with 1 shift. Bits in 6,4,2,0 now move into 7,5,3,1 for the hardware.
for mode 2, it shifts every clock.
for mode 1, it shifts every 2 clocks
for mode 0, it shifts every 8 clocks.
So this in combination with the ANDing explains why the pixels are interleaved like this. The combination of shift and mask makes the pixels for all modes.
If mode 1 had 2 pixels side by side, e.g.
00 11 22 33
You either have to read the pixels differently depending on the mode (= more silicon and more cost) OR you have a setup where for 2 pixel clocks nothing happens, and on the next it is shifted twice! (This means a faster shifter or some delay???) Are there shifters that can do more than 1 time at a time?
Remember in 1983/1984 the hardware was slower and they needed to use very few parts to make it cheap enough.
It's worse for mode 0, you have nothing for 4 pixel clocks, then it's shifted 4 times!!!!
So either a shifter or there is a switch in the hardware where it changes how it decodes it. A switch in hardware means more gates, more silicon, more cost.
I think the existing way was simpler for them to design and cheaper although it seems strange for us.
Quote from: Optimus on 13:27, 05 November 14
And the palette values to color are so weird.
I haven't analysed it, but it may be that some bits define red, some bits define green and some define blue. It does seem weird yes.
Quote from: Optimus on 13:27, 05 November 14
A lot of stuff on the CPC is weird.
cpc is not alone, there are other systems that have weird stuff. The oric atmos has a crazy attribute based mode like teletext! It has codes that turn colours on/off etc.
The enterprise has a fun display list like system. With modes from CPC, c64 and speccy mixed into it.
Quote from: Optimus on 13:27, 05 November 14
Also, what I recently learned and was laughing out loud was, the CPC OUT (C),r is not canon for Z80. it should out register r to port in reg C. But no, it outs to port in reg B. Whaaaat? I mean, I knew this since I was using, but I thought it was a quirk of every Z80 chip itself, not the CPC bad wiring. Also, I think out (C),0 is problematic on CPC?
The OUT mneumonic is confusing.
But B is top 8 bits of address. r is the value to write and C is the lower 8-bits of the address. It's always this way. It really depends on how they connected up the I/O in their design.
Z80 is really meant to have 8 bit i/o addressing because some instructions use B as a counter and the hardware should decode the lower 8-bits so you can output multiple bytes to the same i/o address (OTIR, OTDR), or you can say "hell with that, I want 16-bit i/o address" and now you lost the ability to use those special I/O commands.
OUT (C),0 is only reliable on CMOS Z80's. On NMOS z80's it outputs a different value. It's a "undocumented" opcode because it can give different results depending on z80, but generally 0 for CMOS and ff for NMOS.
Quote from: Optimus on 13:27, 05 November 14
Also, what I recently learned and was laughing out loud was, the CPC OUT (C),r is not canon for Z80. it should out register r to port in reg C. But no, it outs to port in reg B. Whaaaat? I mean, I knew this since I was using, but I thought it was a quirk of every Z80 chip itself, not the CPC bad wiring. Also, I think out (C),0 is problematic on CPC?
OUT (C), r output the content of C on the LSB of the address, the content of B on the MSB of the address, and r on the data bus. This is a Z80 behaviour not a CPC specific one.
Where Amstrad did something not in line with the Z80 'rules' is to use the MSB of the address (B register) where these are usually ignored in other design. This gives 65536 IO register instead of 256 at the expense of the OUT/INI with increment/decrement barely usable.
Quote from: chinnyhill10 on 13:40, 05 November 14
Awful graphics, a ludicrously high price, a speaker that played awful music with no volume control capped off with a total lack of support from the big publishers.
We had a BBC. My experience:
The BBC had a good solid kid proof keyboard with a good typing feel, good fast disc drives, a big solid case that you couldn't break, it had a fast cpu (2mhz 6502!). It had some ok graphics modes.
It had horrible colours. But you could mix them on a television to make others, e.g. purple and green to make grey.
It was horribly expensive. The sound was ok. The cassette loading was 95% reliable, you could rewind if there was an error. It had loads of games and some absolute classics.
It had a stupid sized screen (20K or so!) and very small ram (like 8K by the time you use the screen).
It had great expandability in terms of roms, second processors, hardware. Crazy in fact, hook up all kinds of things to it.
It had a rubbish joystick. Really really bad.
It had it's own set of publishers who liked it and supported it. Superior were THE publishers who produced quality software. Other publishers did do a few games, US Gold, Imagine did some.
Quote from: chinnyhill10 on 13:38, 05 November 14
You only have to look at what happened with the Enterprise to see what problems a long feature list caused. That machine crashed and burned. Amstrad had enough problems with their own gate array!
I don't think the feature list was what killed it.
It appeared to be a company that kept changing mangement, didn't get enough funding and got a computer together that came too late.
Yes using multiple gate arrays probably didn't help.
And superior software also released speech on the cpc!
Quote from: dcdrac on 13:36, 05 November 14
or what was wrong with the C64 and Spectrum?
Spectrum, well if you talk about 48K. It had a horrible rubber keyboard with poor typing experience and many times the games failed to load.
The Speccys with real keyboards were much better. But generally it was ok. Yes the attribute clash was not good, but the resolution was fine.
The original buzzer sound was horrible, the AY much better. It was cheap and ok.
The C64 is good, the only thing that let it down is the slow loading speeds.
Quote from: arnoldemu on 14:43, 05 November 14
The C64 is good, the only thing that let it down is the slow loading speeds.
And vomit colours. And colours per sprite limits.
I think the CPC is great. I am biased because I owned one (we also owned a BBC, and in the past i've owned a C64, Spectrum+3, Amiga etc).
The CPC keyboard has always been great. The original 464 keyboard is close to the BBC's in that it feels good when you type on it and it's strong. The 664 keyboard is nice too, got a good feel when you type on it. The later 464 keyboard and 6128 keyboard is a bit more "cheap" in comparison but still good to type with and has a better layout than 464 and 664.
The built in tape drive is reliable and really easy to get to and use. Less cables than if it was seperate, less chance for loading to fail if you knock the computer.
The built in speaker is ok, a bit low quality, but you can turn the sound up/down. The BBC speaker was always on!
In my opinion there is nothing wrong with the CPC, for the year it was built it is a good solid computer with a fair feature set. The CPU needs more power to work with the hardware, but the general design is well thought out, with a good firmware and hardware.
I do wish they had done the following:
- smooth pixel scrolling
- put AY on it's own I/O address
- put keyboard on it's own I/O address.
I think that would have made games a bit better.
But all of these probably mean a higher cost in hardware development and time.
I do think that the disc interface is rushed together and not as well thought out.
AMSDOS for example is not as well thought out as the firmware. I think with more time it would have had more features and been better designed. It would have had format command built in for example.
Look at the Spectrum+3 DOS, it's what AMSDOS should have been.
Quote from: arnoldemu on 14:40, 05 November 14
I don't think the feature list was what killed it.
It appeared to be a company that kept changing mangement, didn't get enough funding and got a computer together that came too late.
Yes using multiple gate arrays probably didn't help.
The feature list killed it as these relied on the custom chips which were very delayed and hugely pushed up the cost. If you don't promise a massive feature list you won't hit all the problems the Enterprise did.
Sugar originally didn't want any custom silicon in the CPC as he saw what was happening elsewhere. Given the problems Amstrad had with its own gate array you could argue he had a point!
Quote from: steve on 20:50, 04 November 14
Quote
"I remember being fairly rude about a number of mistakes they'd made in the design. It could have been so much better with a couple of tiny changes that wouldn't have cost anything at all. Gah..."
Any idea what these mistakes might have been?
Only one, to forget the wire from the PIO to the 8. bit of the printer port. But this can be fixed easy.
Quote from: gerald on 14:27, 05 November 14
... This gives 65536 IO register instead of 256 at the expense of the OUT/INI with increment/decrement barely usable.
Sadly it doesn't since the upper 8 bits are not fully encoded. In contrast... but at least a couple thousands... look...
Basically the CPC wasn't actually flawed, which explain its success.
Those slight keyboard clashes and the AY somewhat not wired the best way are still some minor details.
To have extra RAM wasn't a problem that couldn't be solutioned as well.
On later ranges of computer, Amstrad would use the same Motherboard with extra RAM slots... be it PC1512/1640 or PCW256/512... or even the PLUS.
Sadly as the CPC464 was their actual first computer, it never really had the same motherboard as CPC6128.
The heavy video modes really make the need for extra RAM something usefull.
harscrolls and sprites and so on would turn it into a compeltely different machine.
So yeah, beside a few I/O and chips Wiring details and some few missing RAM... the design was good enough and quite well rounded.
The Amstrad CPc6128, if it had been the master mold for the range, still remains a powerfull competitor to those speccies or C64, if well coded.
Most of the recent "128k" productions or hacks can proove that a lot as well.
So to me RAM is the main annoying detail that could have changed a lot. Extra 16k are really enough to have the CPC480 handle Speccy port so much betterly and properly re-graphed.
the spanish could almost have done it right... too bad they didn't actually... :laugh:
CPC472 anyone ?
The design was very good for the user. I like how sturdy the machine feels and the keyboard (Hell, I generally love how many of the 8bit keyboards were feeling. Nowadays, PC keyboards are so soft. Might be weird, but I like to feel the keys a bit more. I should check and buy some clicky mechanical keyboard maybe), like the shape and color even if it was like a serious computer (and that's what they were aiming at maybe, making it also a machine for serious business?), that's why 640*200. And fast loading disk with sturdy feeling disks (best disks I have seen ever!). And good Basic. Ok, it was missing a bit on scrolling speed and such compared to C64, but games were still many and quite playable.
But what we talk about is, the hardware design and how much harder it does it for the low level programmer. I agree there were many many quirks. I have tried some C64 and Spectrum and recently Sam Coupe code, and even if every machine has it's quirks, I think they are better. Ok, Spectrum is very simple to program because there is not much, no CRTC, just one resolution, etc. C64 is lovely with it's memory mapped IO, so much easier to do little games, maybe even in basic, with some pokes on memory to control hw sprites, also irq line interrupts and moving chars and hw scrolling 0 to 7, much easier to do even 8 directions scrolling. Sam Coupe is new interesting rare thing for me, not much, no hardware scroll, but line interrupt, can change modes or switch vram pages all over the 512k ram, also without having to trick some kind of CRTC for split. And totally linear vram. But ok, 24k of vram, but I believe many can be done. I also recently read some tutorials for AtariXL, some more well thought design decisions for the programmer.
I didn't like the "one" joystick port and the keyboard clashing. Playing 2 player games whether it be VS or co-op could turn into frustration very easily. I enjoyed BMX simulator 2 with it's 4 player mode as well as others like Jet Ski simulator, but having 3 guys cramped around around a keyboard, interfering with each others controls, ruined the experience.
I also agree with Macdeath in that it should of shipped with 128Kb from the beginning, whether it be a single chip or 2 separate 64kb chips.
I also felt that some form of built in assembler on the ROM chip would of been nice along with the built in basic.
QuoteBut ok, 24k of vram
CPC can do that to, except you'll have 192x256xmode0 full screen instead of 256x192x16 at 6mhz.
CPC is actually somewhat faster in 128x192xmode0 because 4mhz instead of 6mhz but 50% less video.
Had SAM coupé the same modes as CPC it could then do awesome prowness the CPc couldn't... but no it was to chose between speccy or Atari ST... ;D
would have been fun to be able to port CPC games the way they did on enterprise... but at 6Mhz..
Most of the "mistakes" are purely down to the speed at which the CPC was designed, and significantly the rushed change from 6502 to Z80. If they'd done the IO addressing more intelligently (even just swapping high and low address bytes, peripherals could decode the high bits if they wanted) and fixed the pointless missing wait state (rather than regularly every 4th cycle, just WAIT' = every 2nd NOR (RD' NAND WR') would have given the CPU 12% more speed on average). But if the machine worked as it was and it was needed immediately, then it's easier not to fiddle with it...
The screen layout was clearly a conscious decision because it makes it possible to scroll text by character line very quickly. The BBC layout would probably have been slightly more beneficial but it makes graphics drawing a bit less nice. And perhaps that was all designed when the CPC was still 6502 based and they didn't want to appear totally the same as the BBC!
I guess I'm more surprised how popular the CPC became as a games machine, as it was clearly targeting the business/home office user with the monitor which lead to an expensive machine for games use (but of course, more total profit for Sugar!)...
Quote from: sigh on 15:57, 06 November 14
I also agree with Macdeath in that it should of shipped with 128Kb from the beginning, whether it be a single chip or 2 separate 64kb chips.
I don't get what part of "128k in 1983 was expensive" people don't understand. Sugar wanted to hit a price point. We're not talking a few pence difference but doubling the cost of one of the most expensive components in the machine.
Put it this way, a modern computer with 16GB of RAM costs more than a computer with 8GB of RAM.
Quote from: ralferoo on 21:44, 06 November 14
The screen layout was clearly a conscious decision because it makes it possible to scroll text by character line very quickly. The BBC layout would probably have been slightly more beneficial but it makes graphics drawing a bit less nice. And perhaps that was all designed when the CPC was still 6502 based and they didn't want to appear totally the same as the BBC!
I think Roland Perry and co started pretty much from scratch with their design. They were only tied down to the casing and the tape drive. Components that had already been purchased were sold on. The Amstrad Story covers most of this as does the excellent article on The Register a few months back.
I converted this program (http://www.cpc-power.com/index.php?page=detail&num=10515) which relied heavily on BASIC FILL commands, though after converting the program, it wasn't lighting up the keyboard keys which seemed to be the problem.
However, in BASIC 1.0 there was a lag in the sound, maybe because of the extra tasks I was performing to light of the keys perhaps, though my workaround functioned no differently in BASIC 1.1 compared to the original program.
My gut in this case tells me that it's because of the number of Array's in the program and having to setup another one with the appropriate information to light up the appropriate key.
It seems better to clear the array's in BASIC 1.0 because it tends to put a lag on things I've noticed, especially if it's BASIC 1.0 with AMSDOS and one wants to CATalog.
Quote from: sigh on 15:57, 06 November 14
I also agree with Macdeath in that it should of shipped with 128Kb from the beginning, whether it be a single chip or 2 separate 64kb chips.
Loading 128 KB from tape... How long will that take? :o
Smooth scrolling (like the C64) to prevent flick screen, and a more reliable modulator. Other than that, I would change much at all. Speecy ports were not the fault of Amstrad themselves, the pubs put pressure on devs to meet a release date, so they often made shortcuts. Same happened with the GX/Plus cart games (Well, half of them) Shovelware from the CPC due to pressure and, more than likely laziness. At least we got Pang and Robocop 2. :)
Quote from: ralferoo on 21:44, 06 November 14
If they'd done the IO addressing more intelligently (even just swapping high and low address bytes, peripherals could decode the high bits if they wanted)
Actually... that's right! On the other hand for a long time there was no external hardware which would have benifited from block I/O operations. Correct me if I'm wrong.
Quote from: ralferoo on 21:44, 06 November 14
...and fixed the pointless missing wait state (rather than regularly every 4th cycle, just WAIT' = every 2nd NOR (RD' NAND WR') would have given the CPU 12% more speed on average).
That's shocking news! :o At least we can calculate in us on CPC. ;)
Quote from: Novabug on 20:34, 07 November 14
Smooth scrolling (like the C64) to prevent flick screen
The CPC can very easy scroll: Up and down pixel-precise (see Mission Genozide) and in X it's two-Mode-0 pixel-precise (Relentless f.e.). And it's easy to code.
If programmers use speccy ports and are to lazy to change scrolling, don't blame the CPC. ;D
Quote from: TFM on 20:28, 07 November 14
Loading 128 KB from tape... How long will that take? :o
OMG, I'm having flashbacks to the time 3D Construction Kit had a read error on the last few blocks to load and I had to start again. :'(
weren't most CPC tapes using Spectrum loading routines ?
The AA52 Covertape was a Nightmare because The Untouchables had it's music in the extra 64k and it was loading in a Standard SPEED WRITE 0.
At the time I thought nothing would take longer to load than Roland In Time. :'(
Quote from: ivarf on 09:03, 05 November 14
* The low quality built-in speaker. * the memory layout of the screen - every 8-lines * the hardwarescrolling could have been better * hardwaresprites
* no fast charactermode * no low-memory screen-modes * not an option to buy it cheap without a monitor * the external modulator was low quality
* quick and dirty spectrumports * the high sharpedged keyboard
- Well the CPC was produced to a price point TBH. The speaker should have been in the monitor, in stereo, as with the pluses.
- The screen memory layout was a side effect of using a cheap late 70's CRTC controller chip modified to do bitmap graphics in a clever, but esoteric manner.
- Yes, if the gate array had used a slightly bigger GAL/PAL thing, then smoother horizontal scrolling (using the scanline delay method, as used by some other 8-bit micros in conjunction with using the border to hide the edges of the delay) could have been achieved easily.
- Hardware sprites were not an option with the initial design, not without custom hardware.
- This would have required extra work to cope with switching the CRTC from the hacked up bitmap mode into a real character mode. I also don't think you'd have got a fast 80 column mode out of it, as character modes require two reads per character per line, and the CPC had 128 bytes per scanline.
- Again, a limitation of the CRTC and how it was clocked. A half-clock option would have enabled a 64-byte scanline mode with 8KB screen I guess - 2 colour MODE 1 and 4 colour MODE 0 in effect.
- At least CPC owners could use it whilst the main TV in the house was being watched by someone else. But yes, I agree, an option for houses with second TVs. But that modulator ...
- Can't do much about this sadly, lazy programming is lazy programming.
- I liked the keyboard.
More colours - again, a bigger GAL/PAL would have allowed this. Still, they found the space to put in colour swapping hardware :S I'd have settled for 64-colours, 2-bits per R,G,B (the PC1512 did get this palette option I think). Or maybe the Enterprise 64's 256 colours - RGB332.
An 80KB CPC480 would have been neat, that extra 16KB could have allowed more games to have free double buffering and large graphic sets, for example.
Like most 8-bitters, the CPC was a collection of compromises designed to meet a price point. It did well, and it had a real personality.
Quote from: Carnivac on 14:44, 05 November 14
And vomit colours. And colours per sprite limits.
The sad thing is that the C64 reads 4 bits of colour ram per character, and uses it to change 1 colour in that character.
Imagine if that had been used to select 1 of 16 four-colour palettes for that character. Alongside a bit more flexibility on colour range.
If you look at an annotated VIC-2 die shot, you can see why. It's 80% sprite hardware and sprite buffers and character/colour buffers.
Quote from: Sykobee (Briggsy) on 23:14, 07 November 14
An 80KB CPC480 would have been neat, that extra 16KB could have allowed more games to have free double buffering and large graphic sets, for example.
Would a CPC472 be better to some extent?
Quote from: AMSDOS on 23:30, 07 November 14
Would a CPC472 be better to some extent?
TBH given the paging system the CPC has is 16KB in size, I doubt it. Even if the RAM was actually wired in.
With hindsight you can see that RAM prices drop in 1984 to be a lot cheaper, and thus an 80KB CPC would have been viable by the time it was available. Hence the 6128 in '85, the 8256, 1512, etc.
So in terms of this topic - the 464's design should have had passive 80/128KB ram capacity designed in in case of a RAM price drop.
And Amstrad should have released the Plus range a year earlier, and based it around the PC1512/PC1640 hardware or similar, with a custom ASIC for the colours and sound, and stuck in the CPC+ casing.
Quote from: TFM on 20:28, 07 November 14
Loading 128 KB from tape... How long will that take? :o
30 seconds ;D
My 128kb (Datel 64kb expansion) 464 loaded most games into memory barring a few, but I cant remember how long it takes.
Quote from: Sykobee (Briggsy) on 00:35, 08 November 14
So in terms of this topic - the 464's design should have had passive 80/128KB ram capacity designed in in case of a RAM price drop.
Apart from the MSX 1 released in 1983 in which some came shipped with 128kb, where there any other 128kb home computing machines, before 1985?
Quote from: AMSDOS on 23:30, 07 November 14
Would a CPC472 be better to some extent?
Sure if the RAM would be accessible ;-)
Quote from: TFM on 01:09, 08 November 14
Sure if the RAM would be accessible ;-)
or even connected to, let me think, anything ;)
QuoteApart from the MSX 1 released in 1983 in which some came shipped with 128kb, where there any other 128kb home computing machines, before 1985?
Sinclair QL, Machintosh128...
Really... CPC480 would have changed a real lot of things on the paper.
A CPC6160 as well. ;D
Quote from: TFM on 01:09, 08 November 14
Sure if the RAM would be accessible ;-)
So does that mean it doesn't have 72Kb, or it does, but it needs a custom program to access the 8Kb. I know someone had to do this to access the 8Kb in a Multiface 2, it was interesting, though obviously more involved compared to punching out some OUT statements.
Quote from: MacDeath on 02:35, 08 November 14
Sinclair QL, Machintosh128...
Really... CPC480 would have changed a real lot of things on the paper.
A CPC6160 as well. ;D
Useborne Guide To Expanding Your Micro which was published in 1984 has this:
Apple IIC had 128k
Apple IIE 64K Standard Expandable to 128k
Memotech MTX-500 32k Standard Expandable to 512k
A Sinclair QL could be upgraded to 640k
Later Apple IIE machines came with 128k as standard, not sure when this happened though.
Quote from: AMSDOS on 06:51, 08 November 14So does that mean it doesn't have 72Kb, or it does, but it needs a custom program to access the 8Kb.
The inside of the CPC-472 was identical to the original CPC-464 apart from a small add-on card fixed to the original ROM socket and supporting the original ROM, a 4164 RAM chip and a standard logic gates chip. The RAM and logic chips weren't conected at all. Printed circuit lines didn't reach them! This add-on board was only a fake to avoid taxes.(http://old-computers.com/MUSEUM/photos/Amstrad_cpc464_Inside472_s1.jpg)
I quite liked the keyboard; it was ace for its ear. Sure, a bit high, but blew many other machines out of the water...
As for memory, of course, the price point has been mentioned many times in this thread and is pretty simple to grasp. AMSTRAD did know RAM prices were going to drop, hence their product plan for a 664 and a 6128. They wanted the 464 to be the cheapest solution available - instead of adding more RAM when its price fell they preferred to lower the price and stick with their market entry point.
The speaker was tiny, of course, but when it was being designed it was good enough. Instead of a higher-spec speaker I'd have preferred dual speakers (the first time I heard the machine through headphones -Solomon's Key, I think, or Ramparts- I was blown away. Stereo!!!).
As for the modulator: it wasn't so bad back then, compared to the other computers. And don't forget you could get a cheap SCART cable and have perfect picture (no sound of course)!
Quote from: MacDeath on 02:35, 08 November 14
Sinclair QL, Machintosh128...
Really... CPC480 would have changed a real lot of things on the paper.
A CPC6160 as well. ;D
The Sinclair QL - I liked what they were trying to do with this.
Quote from: AMSDOS on 06:58, 08 November 14
Useborne Guide To Expanding Your Micro which was published in 1984 has this:
Apple IIC had 128k
Apple IIE 64K Standard Expandable to 128k
Memotech MTX-500 32k Standard Expandable to 512k
A Sinclair QL could be upgraded to 640k
Later Apple IIE machines came with 128k as standard, not sure when this happened though.
...that's a lot more than I had thought!
Most of those machines were quite expensive though...
That's why I think the 80K approach with empty slots for extras could have been a good compromise.
If i remember some CPC boards series would have some empty chip slots. What was this for ?
Quote from: sigh on 12:33, 08 November 14
The Sinclair QL - I liked what they were trying to do with this.
But what they achived wasn't that impressive. Even the Amstrad CPC was faster than the QL. Basic benchmarks, but still. What were the latest revision of the QL and how long had people to wait before they finally arrived? Many months...
But I am off, I do not what they were trying to achive with the QL
QL was also plagged by those shitty microdrive tape based Mass data storage... seriously ?
With an internal 5"1/4 disk drive "à la CPC6128/664" it would have been a more serious machine.
128K is a bit low on RAM for a 68000 machine as well, but it could easily be extended I guess.
From what I remember, the video modes weren't really good.
QuoteTwo video modes were available, 256×256 pixels with 8 RGB colours and per-pixel flashing, or 512×256 pixels with four colours (black, red, green and white). Both screen modes used a 32 kB
oh, is that a teletext palette ?
Wow, even the speccy actually had a better palette or Am I Wrong ?
Even PC1512 as well... ;D
Video modes manage to be both heavy and inefficient as graphic oriented applications.
Was Sinclair colour blind ?
what about sounds ? don't tell me it is jsut a beeper ?
QL could have been great with at least a real Disk Drive, an AY soundchip and an EGA 64 colour palette to choose inks from.
otherwise it was just a pre-1984 8bit computer fit with a 16bit CPU.
CPC was more well rounded despite being 8bit, Atari ST did it right in 16bits as well.
Quote from: MacDeath on 16:53, 08 November 14
If i remember some CPC boards series would have some empty chip slots. What was this for ?
On pre-asic board, you can either fit 64k*1 bit or 64k*4bit devices. But i've never seen 64k*4bit devices in these.
Quote from: AMSDOS on 06:51, 08 November 14
So does that mean it doesn't have 72Kb, or it does, but it needs a custom program to access the 8Kb. I know someone had to do this to access the 8Kb in a Multiface 2, it was interesting, though obviously more involved compared to punching out some OUT statements.
They just soldered the additional 8 KB on back of another chip. But you can not access it. It's a 64 KB machine. I opened one of the CPC472 couple years ago. The 8 KB chip is there but not connected.
Quote from: MacDeath on 16:53, 08 November 14
Most of those machines were quite expensive though...
Don't know how much they went for, but in 1984 other computer manufacturers had RAM Packs / RAM Chips or RAM Cartridges available and other computers like the Dragon 32 or a Sinclair Spectrum with 16Kb had the option of returning the computer to the Manufacturer for upgrade. I guess if Amstrad gave the option of a 16Kb RAM Pack it would of been a good marketing strategy.
Having said all that, are Amstrad's fussy with regard to what size the RAM is. I guess if the machine works in 16Kb combinations that would work. I had a 386 and put a 4Mb RAM Chip in that along with the other 1Mb Chips which didn't work, I found out afterwards this was a limitation of the 386 and it needed RAM pairs for it to work.
Quote from: AMSDOS on 22:21, 08 November 14
Don't know how much they went for, but in 1984 other computer manufacturers had RAM Packs / RAM Chips or RAM Cartridges available and other computers like the Dragon 32 or a Sinclair Spectrum with 16Kb had the option of returning the computer to the Manufacturer for upgrade.
Dragon and Sinclair both went bust. Tells me all I need to know. Last thing you want is for people to be sending machines back to be upgraded when your machines are made in a state of the art factory in South Korea, compared to Sinclair who made their machines in a factory in Dundee not known for its build quality!
Amstrad had NO interest in selling a RAM upgrade but didn't preclude external suppliers such as DK'tronics supplying them.
Quote from: chinnyhill10 on 00:36, 09 November 14Amstrad had NO interest in selling a RAM upgrade but didn't preclude external suppliers such as DK'tronics supplying them.
The 464 "Expansion Port" is called Floppy Disc Port, because it's a downgraded version that allow to save some electronic parts. Its only usage was to add the DDI-1 that include the ROM7 (triple nand gate decoding) for AMSDOS. When added, the EXT signal is grounded to know if the computer is fully extended. No more, no less.
So, yes, Amstrad had never planned to add memory to this computer and never planed to release the 6128 too.
They have just planed to release the 664, embedding this expansion for peoples with more money. (and a color monitor)
About the DK'Tronics RAM expansions, there was released after the 6128 was out to allow new softwares to be compatible.
So, Amstrad was able to do the same, but... Why doing that if an other company do it for you?
The 464/664 range of computer are not able to properly handle external RAM w/o forcing the /MREQ signal with a transistor.
It's why, most of the existing RAM expansion for 464 are internal and plugged over the Gate Array socket, to avoid this dirty hack.
@chinnyhill10 (http://www.cpcwiki.eu/forum/index.php?action=profile;u=984) is spot on. Amstrad wanted to mass-produce and forget. Hence the higher quality/lower return rates, too. The option to send back to the manufacturer was antiquated even then as an idea, and we all know how behind schedule Sinclair's manufacturing constantly fell...
I have found a way to mold new keyboards... :laugh:
The Keyboard Waffle Iron by Chris Dimino, Designer — Kickstarter (https://www.kickstarter.com/projects/1304060422/the-keyboard-waffle-iron)
Quote from: MacDeath on 17:59, 08 November 14
128K is a bit low on RAM for a 68000 machine as well, but it could easily be extended I guess.
[ot]
The trouble there was an computer like an Apple Lisa which had 1Mb as standard went for nearly $10,000US in 1983 and lacked Colour. Though according to Wikipedia (http://en.wikipedia.org/wiki/Apple_Lisa) the Apple Lisa had a number of differences from the Mac class system with some of the features such as the Protective Memory from the earlier Lisa being implemented into Mac Based Systems.
[/ot]
I wonder if there would of been a cheaper way of creating an 128kb machine by having having 4 32kb chips or even 8 16kb chips on the board.
Quote from: MacDeath on 17:59, 08 November 14128K is a bit low on RAM for a 68000 machine as well, but it could easily be extended I guess.
Megadrive and Neogeo used 64K of RAM for the 68000. When you use ROM, it's not a big problem.
Quote from: sigh on 11:23, 03 December 14I wonder if there would of been a cheaper way of creating an 128kb machine by having having 4 32kb chips or even 8 16kb chips on the board.
As 32KB IC doesn't exist when the 464 was released, it's a false question.
In all cases, 32K IC had been more expensive than two 16K IC. (only saving space on the design had been a good reason to use them)
Quote from: TotO on 11:28, 03 December 14
Megadrive and Neogeo used 64K of RAM for the 68000. When you use ROM, it's not a big problem.
As 32KB IC doesn't exist when the 464 was released, it's a false question.
In all cases, 32K IC had been more expensive than two 16K IC. (only saving space on the design had been a good reason to use them)
But didn't the MSX have 32KB ram chips? They were out before the CPC in 1983.
Quote from: sigh on 14:25, 03 December 14
But didn't the MSX have 32KB ram chips? They were out before the CPC in 1983.
Using different capacity chips wouldn't have had any real effect on the price. The price per Kilobyte was pretty much the same, the only real saving would be on PCB space.
Bryce.
Quote from: sigh on 14:25, 03 December 14But didn't the MSX have 32KB ram chips? They were out before the CPC in 1983.
Is 32K x4bit or 32K x8bit chip?
Quote from: TotO on 17:47, 03 December 14
Is 32K x4bit or 32K x8bit chip?
I have no idea. Is the x4bit version cheaper?
Quote from: Bryce on 15:34, 03 December 14
Using different capacity chips wouldn't have had any real effect on the price. The price per Kilobyte was pretty much the same, the only real saving would be on PCB space.
Bryce.
I see.
Out of interest, if they were to have separate ram chips on the board, would this effect the programming of software? For instance, would separate ram chips have given the coders more control on how the ram is used?
Quote from: sigh on 20:14, 03 December 14
I have no idea. Is the x4bit version cheaper?
That allow to make smaller IC, because less pins.
32K x4bit is 16KB memory.
Quote from: sigh on 20:14, 03 December 14
Out of interest, if they were to have separate ram chips on the board, would this effect the programming of software? For instance, would separate ram chips have given the coders more control on how the ram is used?
No, it doesn't change anything. The address decoding is what defines the limits.
Bryce.