CPC: Underpowered for 1984?

[cwpab]

Firstly, I'd like to clarify that I'm not one of those infiltrated C64 fans. To prove it, you can read one very peculiar Amstrad CPC experience I wrote about recently ( https://www.cpcwiki.eu/forum/games/the-giant-speccy-port-list/msg233993/#msg233993 ).

I also would like to explain that I'm aware of the C64 and ZX Spectrum limitations: the ZX Spectrum was admitedly designed with cost in mind (hence the colour clash, which could have been avoided) and the C64, while having multiple advantages, implemented the most emotionally depressing palette in history (because 1) dark colors were trendy at the time and 2) several colors are just the opposite hex value of some other decent color present to save memory).

The Amstrad CPC offered multiple advantages too. The included monitor made them look more professional than the competition, and the keyboard was nice. It was also easy to get into and had the best colours.

But after reading how it was designed in a very interesting article ( https://www.theregister.com/2014/02/12/archaeologic_amstrad_cpc_464/?page=1 ), I realized they were fist aiming for the 6502 processor, but later switched to the Z80 in the middle of the project just because their engineers knew that one better. Combined with the lack of sprites handling (even if kids were one of their main target market), I wonder if Baron Sugar, even if we love our dear CPCs, sold us a ZX Spectrum with better colours only a few months before the Amiga was released.

What do you think?

[eto]

Underpowered compared to what? And underpowered for what?

Comparing it to the 16bits Amiga and Atari ST is not really fair. They came out just a year after the 464 but they have been SO much more expensive. They addressed a totally different market. In 1986 I would not have been able to afford an Atari ST which was twice as expensive as the CPC 6128. It took the 16bits until 1988 to come down to a similar price level as the 6128 in 1986.

So we can only check if it was underpowered compared to competitors in a similar price range. 

If you would do a comparison with other 8bits, the CPC would probably not be the top computer in any category but it would probably be in the top 3 in all categories. And most other 8bits might have won a category or two - but would have been far below average in others. The CPCs design made sure it was a good all-round computer with no outstanding strength but also with no outstanding weaknesses. 

The question was: what did you want to do - and how much are you able/willing to spend? With my budget, the CPC 6128 was the best option, as it allowed me to do all the things I want. So for me: no, it was not underpowered. It provided what I wanted and needed.  

[ZorrO]

As Eto said, it doesn't matter what year it appeared, just what price range. It won the title of Computer of the Year twice, in 1985 and 1986, because it had the best price-performance ratio.

Of course Atari ST and Amiga were better than CPC. But for several years, ST without a monitor cost about 50% more than 6128 with a color monitor, and Amiga even 100%, so their betterness did not matter for people who couldn't afford 16-bit.

Another story with CPC Plus. With mono monitor cost as much as ST, and with color, as much as A500. At a times when people already had two TVs at home and did not need a monitor.

[Anthony Flack]

I don't know if being 6502-based would have helped. That would just have been a poor man's BBC Micro. The z80 isn't a downgrade, and Spectrum ports were a major benefit.

[SkulleateR]

CPC: Underpowered for 1984?

No

[Brocky]

on par with many micros of its time, just different capabilities..

PCs where not that far ahead of a good 6128 tbh, 6128plus had even more colours than most PCs did at the time..

[andycadley]

The Amiga was crazy expensive in 1985 and well into the category of "high end" systems you didn't really consider. It wouldn't be until about '89 that the costs had reduced to the point they were viable machines for home computing.

And it's easy to forget that the 16-bit home computers started to decline in the early to mid nineties, which wasn't actually that long after the 8-bits started to disappear off the shelves. In both cases it was really the rise of cheap, powerful 16-bit games consoles that are away the market.

[McArti0]

CPC was underpowered for 1984 because has TDP only 10 Watt.
Without joke, CPC was midend claas. Called Half professional.

[cwpab]

Here's an interesting comparison between the Z80 and the 6502: https://retrocomputing.stackexchange.com/questions/5748/comparing-raw-performance-of-the-z80-and-the-6502

[abalore]

In fact I think it was overpowered for the price. The CPC was from the concept an all-in-one budget machine. You can't compare with other machines with other target in mind.

[HAL6128]

The C64 had an unique chance for its time when 3 circuits where designed only for the machine (development already started in 1979): e.g. the SID was developed by musician affin engineer, special graphic chip VIC II... everything in-house with MOS engineering, also the CPU. So best environment situation. And they followed a clear gaming target/clients. This machine was overpowered for the time (1981)

The CPC is completely different: cost-effective like other Amstrad products (lessons learned / as it was with the first IBM PC), only 1 customised chip, rest was bought cheap and heavy available, semi-professional target clients, not only gaming (one joystick port), more office or a beginners/education driven, simple to use (cool Basic). But from hardware side and timing 1984 it's underpowered comparing to the competitors (16-bit area already started)

[HAL6128]

... and this is why I love this machine. Especially the limited AY music. Through the time till today sound chips become / sounds more and more perfect. 
How boring is playing perfect instruments. Everybody ca do this using a iPad and GarageBand.

And... No hw-sprites, but cool and clever programmer found super ways to visualise stuff which can compete with the C64.

Think different!

[Ace]

Amstrad CPC 6128: Best semi-professional use. Best maximum resolution. Best affordable all-in-one design. Best Price.

[cwpab]

I wish the CPC would move as fast as the C64, but I also believe scrolling is overrated. Most of my favorite 2D platformers are screen based (Prince of Persia, Abe's Oddysee, Heart of Darkness, Bruce Lee, Saboteur, Saboteur 2...).

What sadly can't be fixed, and I can't stress this enough, is the feeling of sadness projected by the C64 palette. 

[Anthony Flack]

80 column text and RGB output were not a small deal and something I completely took for granted. But glad that I didn't have to learn to code on a 40 column display going into a TV through a coax cable. And those Infocom adventures were great, too.

If you're designing a game from scratch it's easy to come up with a concept that avoids scrolling. My favourite C64 game is Impossible Mission and that's not a scrolling game either, unless you count the elevators.

The problem is after a certain point games weren't being designed to suit 8 bit hardware any more. 

[zhulien]

I voted No because when I studied my classmates all had 286s and 386s started coming on the market. They were all astounded I could still do my dBase 2 programming and turbo pascal on my CPC, it booted faster than their computers  generally had better graphics and sound too.  Of course the Amiga 500 was on the market too for every years and I ended getting one of those with a GVP 286 card.

[zhulien]

Here's an interesting comparison between the Z80 and the 6502: https://retrocomputing.stackexchange.com/questions/5748/comparing-raw-performance-of-the-z80-and-the-6502

That is interesting a bit but I wonder how accurate the article is.  There are a few 6502 emulators for z80 but no z80 emulators for 6502 for example.  The 6502 ones on z80 usually only used to play SID music files, but they are usually ok with the timing.  Perhaps like cpc music, on a real 6502 the sid playback routines only take a few cycles where as on a z80 they hog the cpu.

[cwpab]

Here's an interesting comparison between the Z80 and the 6502: https://retrocomputing.stackexchange.com/questions/5748/comparing-raw-performance-of-the-z80-and-the-6502

That is interesting a bit but I wonder how accurate the article is.  There are a few 6502 emulators for z80 but no z80 emulators for 6502 for example.  The 6502 ones on z80 usually only used to play SID music files, but they are usually ok with the timing.  Perhaps like cpc music, on a real 6502 the sid playback routines only take a few cycles where as on a z80 they hog the cpu.

It's not an article, it's a question from an user in Stack Exchange. And the answers are pretty impartial: the basic conclussion would be that the 6502 is 2x faster with the same CPU speed as it needs less instructions to do the sameits instructions use less CPU cycles, BUT the Z80 has more registers and a faster RAM access, making it better to program complex operating systems. Not sure how all this affects the early 3D games, though.

[GUNHED]

The 6502 does need less instructions? Really?

Please translate this into 6502 - if you can! 

- LDIR

- SET 3,(IX+99)

- SBC HL,DE

[cwpab]

Yes, you're probably right... I'm not an expert. It looks like what they actually said is that the 6502 instructions use less CPU cycles. 

[Prodatron]

It's obviously, that cwpab mixed instructions with cycles.


A problem of the 6502 is its littel static stack, which makes it impossible to use it in high-level languages. They had to implement their own stack, in software which is much slower.
Another example is Sweet16, this f*ing cool "virtual machine" made by Wozniak for his integer basic. But the Z80 somehow can do all this by itself and would be much faster as well.
I can imagine that this is similiar for 3D stuff though there are pretty good 3D engines for the 6502, too.

[HAL6128]

The 6502 follows more a RISC philosophy where the Z80 more CISC orientated is.

[GUNHED]

Compare Driller on 8 / 16 bit computers - just to have an idea about 3D stuff (w/o hardware acceleration).

imho all 8 (/16) bit cpus are 'risc'-like anyway.

[Prodatron]

imho all 8 (/16) bit cpus are 'risc'-like anyway.

No, not at all.
According to Federico Faggin even the Z80 already has some kind of microcode.

[Anthony Flack]

I've never done any 6502 programming (yet) but I'm kind of curious to have a go at making something for the Vectrex sometime.

That has a 6809, which is a 6800 variant that failed in the market due to being six times the price of the 6502 and Z80. But it has some cool additional features like a relocatable zero page, two stacks, and it can multiply two 8 bit numbers in hardware.