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General Category => Amstrad CPC hardware => Topic started by: eliot on 14:33, 21 August 10

Title: CPC Parts
Post by: eliot on 14:33, 21 August 10
Hello,

CPC Parts is new site to provide parts and hardware for CPC Users.  
http://amstradcpc.info/parts/about.php (http://amstradcpc.info/parts/about.php)

Hope it can be useful!  :D

Eliot
Title: Re: CPC Parts
Post by: steve on 14:56, 21 August 10
This site will be excellent addition to the CPC community, now it needs to offer some electronic parts, I am looking for 64kx4 dynamic ram and sed9420 data separator, and I look forward to seeing what new hardware will be produced by others for sale on this site.

I wish it every success.
Title: Re: CPC Parts
Post by: Bryce on 21:56, 22 August 10
Hi Eliot,
       I'm sure it's a great site, but when I click on your link I get the site for half a second then I get forwarded to a 404 page. Even if I leave the "about.php" off, I still end up on the 404. Maybe it's just my PC? Anyone else having the same issue?

Bryce.
Title: Re: CPC Parts
Post by: steve on 23:57, 22 August 10
I have just been to the site and it appears to be working.
Title: Re: CPC Parts
Post by: TFM on 02:52, 23 August 10
Quote from: eliot on 14:33, 21 August 10
Hello,

CPC Parts is new site to provide parts and hardware for CPC Users. 
http://amstradcpc.info/parts/about.php (http://amstradcpc.info/parts/about.php)

Hope it can be useful!  :D

Eliot

Fantastic site eliot! Do you know where I can get the plastic cases of CPC-Plus cartridges?
Title: Re: CPC Parts
Post by: Gryzor on 08:23, 23 August 10
Nice effort... really! Instead of relying on eBay vendors, it'd be sweet to have an one-stop shop! A shame I just bought a few belts just yesterday!

Oh, I also saw the reset switch, which according to the description can be used as a hard-pause button. I don't think I remember reading anything about that... any info on pausing the CPC??
Title: Re: CPC Parts
Post by: eliot on 08:40, 23 August 10
Thank you for the first comments! I'm not an hardware specialist at all but I've just created something I thought important for the real CPC users.
@ Bryce : the site seems to work everywhere... Which browser? 
@TFM: Plastic case for Plus cartridges : no idea.  
@ Gryzor : Pause button : http://www.phenixinformatique.com/modules/smartsection/item.php?itemid=90 (http://www.phenixinformatique.com/modules/smartsection/item.php?itemid=90)
Title: Re: CPC Parts
Post by: Bryce on 08:52, 23 August 10
Morning Eliot,
      I just tried the site on a different PC (XP with Firefox) and everything seems to work fine (nice site by the way). Last night I had tried it on a laptop with Windows 7 / Firefox, will have to investigate what's wrong, seems to be a problem with the laptop :(

Bryce.
Title: Re: CPC Parts
Post by: Gryzor on 10:06, 23 August 10
Quote from: eliot on 08:40, 23 August 10

@ Gryzor : Pause button : http://www.phenixinformatique.com/modules/smartsection/item.php?itemid=90 (http://www.phenixinformatique.com/modules/smartsection/item.php?itemid=90)

Intriguing and very easy to do... But how does it work? Also, is it sure to not cause any problems, software-wise?
Title: Re: CPC Parts
Post by: eliot on 13:42, 23 August 10
It freezes the activity : no mode color cycling, no more rasters, no more split-screen or other CRTC features that require synchro... So it's interesting to study how a demo or program works. But we're off-topic... 
Title: Re: CPC Parts
Post by: Gryzor on 06:23, 24 August 10
Yeah, but still: *how* does it work? What does it do to the CPC?
Title: Re: CPC Parts
Post by: Bryce on 08:39, 24 August 10
Morning Gryzor,
      here's a quick explanation:

The pause switch shorts the "Ready" signal to ground (which is connected to the WAIT pin of the CPU). Normally, when the CPU requests data, it expects an answer within a certain time This signal is used for external peripherals that need a little extra time to answer, by grounding this pin, the peripheral says "Hang on a minute, I'm not ready yet". A useful signal, if the hardware is too slow, or if it has a lot of calculating to do which can't be completed within the time the CPU expects. By shorting it, you're fooling the CPU into thinking that it's last requested data isn't ready to be sent yet. It has a major down-side however: The CPU doesn't refresh the memory properly while this pin is held low, so pausing for any significant time (and I'm talking milliseconds here) could cause the RAMs content to get corrupted, so I can't see this device being very useful.

Bryce.
Title: Re: CPC Parts
Post by: arnoldemu on 09:23, 24 August 10
Quote from: Bryce on 08:39, 24 August 10
Morning Gryzor,
      here's a quick explanation:

The pause switch shorts the "Ready" signal to ground (which is connected to the WAIT pin of the CPU). Normally, when the CPU requests data, it expects an answer within a certain time This signal is used for external peripherals that need a little extra time to answer, by grounding this pin, the peripheral says "Hang on a minute, I'm not ready yet". A useful signal, if the hardware is too slow, or if it has a lot of calculating to do which can't be completed within the time the CPU expects. By shorting it, you're fooling the CPU into thinking that it's last requested data isn't ready to be sent yet. It has a major down-side however: The CPU doesn't refresh the memory properly while this pin is held low, so pausing for any significant time (and I'm talking milliseconds here) could cause the RAMs content to get corrupted, so I can't see this device being very useful.

Bryce.
Why did I think of HAL in 2010 when I read this?

I press the button, the screen starts to corrupt and the CPC starts singing: "Daisy Daisy give me your answer do"
Title: Re: CPC Parts
Post by: Bryce on 10:12, 24 August 10
Oh yeah, I forgot to mention that the CPC starts singing "Daisy, Daisy" decreasing in speed and tone until it fades away. It also warns you, that "I wouldn't do that if I were you Dave" as soon as your fingers approach the pause button :D

Bryce.
Title: Re: CPC Parts
Post by: arnoldemu on 15:09, 24 August 10
Quote from: Bryce on 08:39, 24 August 10
It has a major down-side however: The CPU doesn't refresh the memory properly while this pin is held low, so pausing for any significant time (and I'm talking milliseconds here) could cause the RAMs content to get corrupted, so I can't see this device being very useful.
Thinking about it seriously.  The CPU doesn't refresh the ram in the CPC design.

The CRTC generates addresses and the gate-array reads the data and generates the screen. At the same time the ram is also effectively refreshed.

This is why it is possible to setup the CRTC so that the ram is not refreshed correctly. This is mentioned and can happen more easily on the CPC+ ;)
Title: Re: CPC Parts
Post by: Bryce on 15:32, 24 August 10
Yes, but external Dynamic memory devices (DKtronics etc) would use the CPU generated Refresh signal? Where I assume "Daisy, Daisy" has been saved?

Bryce.
Title: Re: CPC Parts
Post by: TFM on 21:12, 24 August 10
Quote from: Gryzor on 08:23, 23 August 10
Oh, I also saw the reset switch, which according to the description can be used as a hard-pause button. I don't think I remember reading anything about that... any info on pausing the CPC??

I have a small expansion card, built like despicted in Happy Computer 1987 (or so), it can smoothly slow down the CPC until it freezes, nice for some games.

Quote from: Bryce on 15:32, 24 August 10
Yes, but external Dynamic memory devices (DKtronics etc) would use the CPU generated Refresh signal? Where I assume "Daisy, Daisy" has been saved?

Bryce.

Like I remember RAM expansions (of external nature) must have their own refresh. At least Dobbertin was writing something about this in his handbook of the 512 kB expansion.
Title: Re: CPC Parts
Post by: Bryce on 21:51, 24 August 10
Yes they have their own Refresh circuitry, but it reads the Refresh signal to know when it's the right time to do it. If that signal is paused, then they wont refresh.

Bryce.
Title: Re: CPC Parts
Post by: CloudStrife on 10:49, 25 August 10
Well, we speak about CPC... Who need a RAM extension on CPC ?
(And it's depand on extension design, you can build a refreshing without using /RFSH at all...)
Title: Re: CPC Parts
Post by: Bryce on 13:06, 25 August 10
Of course, I was just pointing out a technical detail which doesn't seem to have been mentioned anywhere else.
I also use a "bare-bones" CPC with no extra RAM.

Bryce.
Title: Re: CPC Parts
Post by: TFM on 20:57, 25 August 10
Quote from: CloudStrife on 10:49, 25 August 10
Well, we speak about CPC... Who need a RAM extension on CPC ?

People who don't like to live in caves?  8)
Title: Re: CPC Parts
Post by: Gryzor on 07:11, 26 August 10
Quote from: Bryce on 10:12, 24 August 10
Oh yeah, I forgot to mention that the CPC starts singing "Daisy, Daisy" decreasing in speed and tone until it fades away. It also warns you, that "I wouldn't do that if I were you Dave" as soon as your fingers approach the pause button :D

Bryce.

Not very clever; what if I'm not called Dave?
Title: Re: CPC Parts
Post by: Bryce on 10:28, 26 August 10
There wasn't enough RAM free to digitise "Themistocles" :D So they went with Dave.

Bryce.
Title: Re: CPC Parts
Post by: CloudStrife on 11:00, 26 August 10
Quote from: TFM/FS on 20:57, 25 August 10
 
People who don't like to live in caves?  8)
Yep... And we can had a external processor like a Core 2 Duo, a Sound Blaster Audigy, and a new graphic card...
Title: Re: CPC Parts
Post by: Bryce on 14:46, 26 August 10
I'll get to work on the Sound Blaster extension right away :) Not sure how I'm going to get the nVidia GTX485 connected though, I may need to overclock the Z80 a little :D

Bryce.
Title: Re: CPC Parts
Post by: eliot on 14:52, 26 August 10
[OFF-TOPIC post around a lot of other OFF-TOPIC posts]
I really admir the abalaties of people to divert from the original subject!  :P
[/OFF TOPIC OFF]
Title: Re: CPC Parts
Post by: Bryce on 15:22, 26 August 10
Oops, sorry Eliot, back to the real subject (I assume the CPC parts page is from you). Are you actively seeking suppliers for CPC parts, or is it just stock you've obtained? I have a list of suppliers, that I can check to see if they still exist, where I've bought 8-bit parts for repair purposes (old dynamic RAM and other hard to get bits). If you're interested, I can send you a list of the ones that are still in business?

Bryce.
Title: Re: CPC Parts
Post by: eliot on 17:06, 26 August 10
I can't find edge-card connectors (34 pins and 50 pins) for classical CPC any more here. I had the luck to find a big stock of 50 pins ones when building CPC Parts. 
Title: Re: CPC Parts
Post by: Bryce on 18:38, 26 August 10
Yeah, edge-connectors are really a thing of the past. For the Digiblaster edge-connectors (34way), I collected all the old PC Floppy drive cables I could find and salvaged the 5.25" edge-connector from those. There's a small separator that needs to be carefully removed, but it's not that difficult. Everyone has an old PC in the attic and there's two connectors on each cable, which should keep us going for a few years. :) I only have two 50way edge-connectors left and I'm willing to fight to the death before I'll give them away :D

Bryce.
Title: Re: CPC Parts
Post by: TFM on 05:08, 27 August 10
Quote from: Bryce on 14:46, 26 August 10
I'll get to work on the Sound Blaster extension right away :) Not sure how I'm going to get the nVidia GTX485 connected though, I may need to overclock the Z80 a little :D

Bryce.

Well, I have a CPC running with 6 MHz instead of 4 MHz, just use a Z80B or better. No problem. Would be great if Eliot can also sell the needed 24 MHz crystal and the Z80B (or better the Z80H), but only in case that some people want to speed up their CPC.


Quote from: CloudStrife on 11:00, 26 August 10
Yep... And we can had a external processor like a Core 2 Duo, a Sound Blaster Audigy, and a new graphic card...

Well, if you like... I'm totally happy with a CPC6128 with 512 exansion RAM (used mainly as RAM disc, battery buffered for sure), some ROMs (Protext) and a printer. Why? Well, I can work more quick than you can with your new high-end PC! Let me explain this in detail. Your PC needs 20 seconds to boot and you need 10 seconds to write a letter. With my expanded CPC I need 1 second to boot, 2 seconds to enter Protext, 10 seconds to write a letter, and if needes another second to save my letter to the battery-buffered RAM-disc. THEREFORE you need an expandet CPC!

Further if I would have the time I would name you a huge lot of programs which actually need more than 128 KB or gain strong advantages from it. Discology is only one example...
Title: Re: CPC Parts
Post by: Bryce on 08:34, 27 August 10
My final goal is obviously, that the CPC can run Crysis :D

Regarding 24Mhz Crystals, they're hardly rare, you can pick them up anywhere, so it would be pointless offering them on a CPC parts site? Unless it was an upgrade kit = 24Mhz xtal, Z80B, instructions etc.

Bryce.
Title: Re: CPC Parts
Post by: Gryzor on 09:00, 27 August 10
I've got a Cirrus Logic 5401 lying around somewhere if you're interested...
Title: Re: CPC Parts
Post by: steve on 13:33, 27 August 10
I think a second processor would be better, a plug-in expansion box containing a processor and 1-4MB ram with a 16KB rom to manage communication between the CPC and the 2nd processor, the second processor could run at 20Mhz without being slowed down by the ULA or running OS routines.
Title: Re: CPC Parts
Post by: Ynot.zer0 on 14:01, 27 August 10
I have an Amstrad book that explains about how to add a 2nd CPU to the CPC 464 as a hardware project.  (I'll see if I can find it and what it is called - not sure if anyone has it scanned and upload to the wiki?)
Title: Re: CPC Parts
Post by: TFM on 20:18, 27 August 10
Quote from: steve on 13:33, 27 August 10
I think a second processor would be better, a plug-in expansion box containing a processor and 1-4MB ram with a 16KB rom to manage communication between the CPC and the 2nd processor, the second processor could run at 20Mhz without being slowed down by the ULA or running OS routines.

In this case your system is like a keyboard and a PC. Don't know it keyboards still have a Z80 inside, but a second CPU (if stronger) degrades the CPC to a "keyboard"

I like the 4 MB RAM expansion from Jarek (in the 6128 internal), that's amazing. And this RAM is actually used by few programs, but soon there will be more apps. unsing the 4 MB.

However, 2. cpu cards exists already:

- Thre rare HD64180 card and...
- The very wondeful CPC Booster!

Title: Re: CPC Parts
Post by: steve on 22:02, 27 August 10
Quote from: TFM/FS on 20:18, 27 August 10

In this case your system is like a keyboard and a PC. Don't know it keyboards still have a Z80 inside, but a second CPU (if stronger) degrades the CPC to a "keyboard"


- Thre rare HD64180 card and...
- The very wondeful CPC Booster!

I prefer to think of one z80 running the OS and drawing the screen while the 2nd z80 is running the application(s).
Title: Re: CPC Parts
Post by: TFM on 20:21, 28 August 10
Ah, a system like they used in the GenieIIIs, which had two Z80 with 8 MHz. Well, why not  ;)

But to make it easy, you can connect two CPCs for that issue. Using CPC Booster or the VN96 network.
Title: Re: CPC Parts
Post by: steve on 02:34, 29 August 10
Wikipeadia and oldcomputers.com say the video genie III used a single z80a running at 3.2 Mhz otherwise I would like a machine with two z80s running at 8Mhz each.

I am currently considering buying a vz80p+ which has a z80 running at 16Mhz, 1152KB ram and an FPGA containing a blitter and 8-bit DAC for audio samples.
Title: Re: CPC Parts
Post by: TFM on 07:15, 29 August 10
Quote from: steve on 02:34, 29 August 10
Wikipeadia and oldcomputers.com say the video genie III used a single z80a running at 3.2 Mhz otherwise I would like a machine with two z80s running at 8Mhz each.

You look a "video genie III", but I was talking about the TCS Genie IIIs, which has a Z80H with 7.2 MHz. Mine has 8 MHz (special version for a medical system) and it has the legendary Ultra/8 card which has an extra Z80H running at 8 MHz. Both CPUs can access the same RAM at the same time. Das ist einfach genial!!! But there is enough RAM for the cpu's anyway. And there is a extra 64 KB of Video-RAM for the GenieIIIs. So it has high-resolution gfx - and it has a ultra-fast text mode. And both - gfx and text mode - can be displayed at the same time.
BTW: The Genie III s has two Z80-SIO and two Z80-PIO, it has a huge number of connections to the outworld. Can even control supersonic devices to communicate ;-)
Originally is was very, very expensive. I had the luck to get it 15 years ago for 500 Deutsche Mark (= 250 Euro).

Quote from: steve on 02:34, 29 August 10
I am currently considering buying a vz80p+ which has a z80 running at 16Mhz, 1152KB ram and an FPGA containing a blitter and 8-bit DAC for audio samples.

Does it have a real Z80? Or a "similar" cpu? If it is a real Zilog Z80, then this machine is of particular interrest.
Title: Re: CPC Parts
Post by: steve on 05:33, 30 August 10
TCS genie III sounds like a fast machine, does it run CP/M?

The v6z80p+ uses a real z80 but I don't know if it is made by zilog, apparently they gave free licences to any company to make the z80 and so have made less than half the number of z80's made since it was introduced.
Title: Re: CPC Parts
Post by: TFM on 23:31, 30 August 10
Quote from: steve on 05:33, 30 August 10
TCS genie III sounds like a fast machine, does it run CP/M?

It's not the Genie III, I'm talking about the Genie IIIs.  ;)  This is actually a big difference  :)

It runs CP/M 2.2, CP/M Plus, Newdos 80, TRS-DOS, and some other DOS. There are two versions of CP/M Plus. Both are way superior to every other implemention that I've ever seen. The had a really positive competition.

BTW: It also runs CISS, it's like FutureOS for the CPC, but I have no time to develop it further  :(

Quote from: steve on 05:33, 30 August 10
The v6z80p+ uses a real z80 but I don't know if it is made by zilog, apparently they gave free licences to any company to make the z80 and so have made less than half the number of z80's made since it was introduced.

Can you provide a link? I didn't find anything in the net. Sounds like an interresting machine.
Title: Re: CPC Parts
Post by: steve on 00:34, 31 August 10
Quote from: TFM/FS on 23:31, 30 August 10


Can you provide a link? I didn't find anything in the net. Sounds like an interresting machine.

http:// (//http:///)www.retroleum.co.uk/electronics-articles/v6z80p/
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