Things you never knew about the CPC?

[Nemesis]

I hear what you're saying but given the choice I would've rather had a playable flick screen Green Beret in comparison to the juddering push scrolling effort that us CPC owners were left with.

i'm not going to disagree with that either, but the point raised was how good Gryzor is as a conversion and, as a conversion of a scrolling run and gun game, it's rather lacking in one of those elements. Regardless of how good a game we feel it to be, there will have been people paying their pennies and being disappointed when it finished loading. Fingers crossed most of them still sat down and played it properly to find out how good it actually is.

Similar to the Spectrum vs CPC versions of Cauldron where you are flying around the landscape on your broomstick. The speccy uses the horrible push scrolling effect where the CPC adopts the flick screen method & plays all the better for it. Of course, you could've just had the C64 version which had smooth scrolling from the off.

It works in every direction, Action Biker is isometric 3D scrolling on the C64 and Atari 8-bit but 2D on the Spectrum, Amaurote is isometric 3D on everything apart from the top down view C64 version and in most of those cases the one doing things differently is considered inferior. Amaurote is pretty naff on the C64 but as designer Ste Pickford points out, "so most of our efforts and energy were directed at the technical aspects of the Spectrum version, there wasn't that much of a game concept to hang the C64 version around" so as far as he's concerned they're all naff and the C64 one is just naff in 2D. =-)

Swings & roundabouts of the 8-bit era eh. If I was a rich kid back then, I would've owned all three formats & been like a pig in censored.

[ivarf]

Do you want a 6502 @ 2mhz ? you need faster rams. More expensive. Otherwise, 1Mhz (or if you prefer a 4Mhz z80, that is the same).

Yes, i know but it's irrelevant to that post of mine from a couple of years back that you necro quoted; i wasn't just randomly saying "lets stick a 6502 in the Amstrad, i guess it might work", i was basing the theorising on the fact that a 6502-based prototype existed, so either it had fast enough RAM and was clocked at 2MHz or someone at Amstrad was a few sarnies short of a picnic and thought 1MHz would be fine for shunting a 16K screen RAM about... i'm guessing the former because i'd like to think Amstrad didn't employ nutters. =-)

In this case they did. Thank good they didn't finish it and released this Vic 464 Oric

It was a shame that the CPC was 3rd to the market because developers in this country weren't using the CPC as a target platform in most instances for development, unlike in France, Spain or Germany. Often the CPC would receive not just ports but a port of another port ie Arcade > ZX Spectrum > CPC meaning it's potential was often not realised. T

I think the Speccy was the target platform in Spain too. Germany? I assume the C64 was the target platform there, but I guess the Amstrad CPC was the target Z80 platform if it was actually coded in Germany. France? Maybe. Could someone from France shed some light on this?

[Nemesis]

It was a shame that the CPC was 3rd to the market because developers in this country weren't using the CPC as a target platform in most instances for development, unlike in France, Spain or Germany. Often the CPC would receive not just ports but a port of another port ie Arcade > ZX Spectrum > CPC meaning it's potential was often not realised. T

I think the Speccy was the target platform in Spain too. Germany? I assume the C64 was the target platform there, but I guess the Amstrad CPC was the target Z80 platform if it was actually coded in Germany. France? Maybe. Could someone from France shed some light on this?

Maybe the Speccy was a target platform in Spain too, however, the general impression I've got over the years was that the CPC didn't receive cheap hand me down ports from Sinclairs machine as was the norm in the UK. Dinamic's games for example were usually tailored towards the CPC's 16 colour graphics mode (Mode 0). It's only one developer of course but I don't recall too many almost monochromatic games appearing from the continent showing their Spectrum roots.

[ivarf]

It was a shame that the CPC was 3rd to the market because developers in this country weren't using the CPC as a target platform in most instances for development, unlike in France, Spain or Germany. Often the CPC would receive not just ports but a port of another port ie Arcade > ZX Spectrum > CPC meaning it's potential was often not realised. T

I think the Speccy was the target platform in Spain too. Germany? I assume the C64 was the target platform there, but I guess the Amstrad CPC was the target Z80 platform if it was actually coded in Germany. France? Maybe. Could someone from France shed some light on this?

Maybe the Speccy was a target platform in Spain too, however, the general impression I've got over the years was that the CPC didn't receive cheap hand me down ports from Sinclairs machine as was the norm in the UK. Dinamic's games for example were usually tailored towards the CPC's 16 colour graphics mode (Mode 0). It's only one developer of course but I don't recall too many almost monochromatic games appearing from the continent showing their Spectrum roots.

Here is some more information on how it was done
http://www.cpcwiki.eu/index.php/Games_Crossdev

Not the full story but it gives some clues

[andyc]

Would be interesting to know what is fastest and smoothest of CPC+, C64 and Atari ST for typical C64-style shootemups.

Probably still the C64, because it can scroll the background (i.e. the entire screen) in hardware, taking no time at all.

It can only scroll eight pixels before having to reset the hardware smooth scroll registers and shift the screen RAM about with CPU grunt. The screen RAM itself can be double buffered in software so there's however many frames of CPU time available to copy it in chunks as the hardware scroll does it's job, but the colour RAM can't be moved in memory so any shifting of that is racing the raster scan.

By contrast, the CPC+ can shift the entire display continuously a pixel at time without ever having to resort to block copying in software. It does make screen address calculations something of a nightmare though!

Yes, i know but it's irrelevant to that post of mine from a couple of years back that you necro quoted; i wasn't just randomly saying "lets stick a 6502 in the Amstrad, i guess it might work", i was basing the theorising on the fact that a 6502-based prototype existed, so either it had fast enough RAM and was clocked at 2MHz or someone at Amstrad was a few sarnies short of a picnic and thought 1MHz would be fine for shunting a 16K screen RAM about... i'm guessing the former because i'd like to think Amstrad didn't employ nutters. =-)

I dunno, most of the internal timing of things in the CPC is geared around a 1MHz clock, so I wouldn't be overly surprised if the original 6502 design was still 1MHz. It would have been a bit pants for gaming, but for the kinds of text based scrolling the CPC design is optimised for it would have made no difference, because that's all done in hardware anyway.

Ultimately though the Z80 won out not only because Locomotive had a ready-made Z80 basic, but also it allowed the machine to be used for CP/M and Amstrad had designs on it being used as a cheap business computer as much as (if not more than) a home games system.

[TMR]

Yes, i know but it's irrelevant to that post of mine from a couple of years back that you necro quoted; i wasn't just randomly saying "lets stick a 6502 in the Amstrad, i guess it might work", i was basing the theorising on the fact that a 6502-based prototype existed, so either it had fast enough RAM and was clocked at 2MHz or someone at Amstrad was a few sarnies short of a picnic and thought 1MHz would be fine for shunting a 16K screen RAM about... i'm guessing the former because i'd like to think Amstrad didn't employ nutters. =-)

In this case they did. Thank good they didn't finish it and released this Vic 464 Oric[/quote]

It's not that bad an idea... it'd just be a BBC Micro with more colour and less display options, so all those amazing BBC coders like Orlando or Gary Partis who'd had a couple of years getting to grips with CRTC hammering could've picked it up relatively quickly. The CPC should have Fire Track...

[ivarf]

Yes, i know but it's irrelevant to that post of mine from a couple of years back that you necro quoted; i wasn't just randomly saying "lets stick a 6502 in the Amstrad, i guess it might work", i was basing the theorising on the fact that a 6502-based prototype existed, so either it had fast enough RAM and was clocked at 2MHz or someone at Amstrad was a few sarnies short of a picnic and thought 1MHz would be fine for shunting a 16K screen RAM about... i'm guessing the former because i'd like to think Amstrad didn't employ nutters. =-)

In this case they did. Thank good they didn't finish it and released this Vic 464 Oric

It's not that bad an idea... it'd just be a BBC Micro with more colour and less display options, so all those amazing BBC coders like Orlando or Gary Partis who'd had a couple of years getting to grips with CRTC hammering could've picked it up relatively quickly. The CPC should have Fire Track...

With the right people doing the design, I agree. But with the 6502-people Amstrad had hired, the machine would have had no success. They didn't have a clue. Anyway thats what I read in Amstrad User at the time. In an interview with the designers that was hired to fix the mess from the previous designers they told about this. Considering the short time they had to come up with a new machine, I think they did a pretty good job. If only they could have been hired from the start...

[Treguard]

The CPC 464 is easier to beat a man to death with than a C64 due to it's built in cassette deck.

[TMR]

The CPC 464 is easier to beat a man to death with than a C64 due to it's built in cassette deck.

Not if the C64 had a disk drive...

[old 8088]

A 2MHz 6502 will pull about the same as the Z80a that was fitted, if they didn't manage to clock it up to that speed it'd hardly be surprising if people complained.

The problem is more complex, here. To have a 6502 running @2Mhz you need faster hw, especially RAM chips.
With faster ram chips, you can get 6502 @2Mhz . But, with the same bandwidth you can *more easily* get a z80 @8Mhz.

The reason for the the z80 being more 'fast' is not on the pure clock speed. For the z80, a higher clock rate *IS* a requirement. So to be more clear, having a 6502 @1Mhz is usual as having a z80 @3.5Mhz!. This is because both chips used the external clock in different ways, so pratically it's like as the z80 used the external clock divided by 4 internally. (4Mhz/4->1Mhz approximately).

However, because of design , you can safely use a z80@4Mhz with ram chips that can keep up with a 6502@1Mhz.

The reason that justify the better performances on z80 compared with 6502, are to be searched in some architectural differences on the z80. Those differences can give a 'boost' in terms of performances that can range from 30 to 200% more , depending on pratical use or situations.

Of course, i can give you ad-hoc examples to claim the z80 is a lot FASTER than 6502, and vice-versa. Those examples are, however specifically created to dimostrate one or another thing. The real use case, show, however, that with a 6502 @1Mhz and a z80 @3.5Mhz, the gain in speed is very variable, and by something about 30% and 200%.

[storm_maker]

I think Its a shame the CPC existed. In my opinion the UK gaming industry would've been much better off had Acorn done a better job of cost-cutting the BBC. If they'd made an Electron which retained more of the Beebs features, but cut down the build quality to decrease price (and got it out on time) I think they would've been onto a winner, and we would've had a much more efficient triumvirate of computers, with developers being spread less thin.

The Beeb already had its own stalwart companies supporting it, Acornsoft, Superior, Micro Power etc, adding the likes of Ocean/Virgin/US Gold/Codemasters and all the others to this foundation would've created a much better games machine IMO, and we'd have had three very different game scenes on the market (as opposed to what happened with the CPC being generally a port machine), on top of that, children and students learning programming on the Beeb (which was largely the computer of choice in schools in the old days) could've gone on to make Electron games.

Failing that we'd have been better off had Amstrad never made the 464, and had simply released a tape deck + 128k memory machine sold without a monitor (to reduce prices) for the mainstream market, to go with the normal 6128 with choice of colour or monochrome for the higher end market. Mainly I think that because the 128k model seemed to have a lot more promise and untapped capability (overall it seems much less hamstrung).

We also needed the Spectrum discontinued ~1986 and replaced with the "Spectrum 2" a machine with hardware scrolling and sprites.