Off for a trip to CPC land

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stephen_usher
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Re: Off for a trip to CPC land

Post by stephen_usher »

:dualthumbup:
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
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Re: Off for a trip to CPC land

Post by rubber_jonnie »

Since playing with the CPC some more now I have the ULIfAC, which seems to work on a similar principle to the FreHD (I must finish that project!!), I've noticed a peculiar thing.

If I have a joypad/stick plugged in, I get random keypresses when sitting at the BASIC prompt. It appears to be the fire button being pressed. It doesn't happen when there is nothing plugged in.

So I did some testing last night, and the following sticks had this behaviour:
  1. Atari 7800 joypads
  2. Cheetah Mach 1
  3. Atari Pro Line joystick
  4. Sega Mega Drive Game Pad
The following worked just fine with no random keypresses:
  1. Competition Pro
  2. Sega Mega Drive Game Pad
I don't have others to test, but this struck me as odd, and likely a joystick issue, not a CPC issue. Those sticks that failed at the BASIC prompt worked just fine in games, and on other platforms, and they all have different mechanisms, so spring dome, microswitch, rubber dome etc.

I may have a look inside to see why the two that worked fine are different, and I am wondering if there are additional components that they have, that the others don't.

I'll just use the Game Pad for now as it suits me better than the Competition Pro, but I thought it odd and worth mentioning to see if anybody else had experienced this.

EDIT: The Mega Drive Game Pad is now on the naughty list after a bit more testing.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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PhilC
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Re: Off for a trip to CPC land

Post by PhilC »

@rubber_jonnie other than a ram upgrade, what does the UliFac do exactly and how much was it?
If it ain't broke, test it to Destruction.
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rubber_jonnie
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Re: Off for a trip to CPC land

Post by rubber_jonnie »

PhilC wrote: Sat Nov 04, 2023 12:33 pm @rubber_jonnie other than a ram upgrade, what does the UliFac do exactly and how much was it?
It offers the RAM upgrade, ROM slots, the possibility to set your CPC 464 into CPC1628, there is a serial port, USB port for thumb drives and floppy emulation, plus the option of WiFi. For €45 it's a bit of a bargain TBH and that included postage from Greece.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
stephen_usher
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Re: Off for a trip to CPC land

Post by stephen_usher »

Do the joysticks which show random key presses have auto-fire?

Also, the Amstrad joystick port is not quite Atari as it supports a second fire button or a second stick which has time sliced input selection I think. I guess that could be upsetting things.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
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Re: Off for a trip to CPC land

Post by rubber_jonnie »

stephen_usher wrote: Sat Nov 04, 2023 5:48 pm Do the joysticks which show random key presses have auto-fire?

Also, the Amstrad joystick port is not quite Atari as it supports a second fire button or a second stick which has time sliced input selection I think. I guess that could be upsetting things.
The Cheetah and Competition Pro do have auto fire, but the Cheetah has the problem, and the Competition Pro works just fine. None of the others have auto-fire. I had read that auto-fire requires 5v too, that the CPC doesn't provide on the joystick port.

Looking at the schematic, the joystick port is essentially an extension of the keyboard:

Screenshot 2023-11-05 at 10.24.31.png
Screenshot 2023-11-05 at 10.24.31.png (526.89 KiB) Viewed 114 times

So any uncommanded inputs would show up as a keypress, what I'd like to understand is why the Competition Pro just works, but the others don't.

The Sega Game Pad was the strangest, as when plugged in, there were no random keypresses like with the others, but if you started typing it suddenly went mad and threw in loads of random keypresses.

Might open up a couple of them today and see why the CP is different.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Icky
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Re: Off for a trip to CPC land

Post by Icky »

Pull-ups in the joystick may be?
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rubber_jonnie
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Re: Off for a trip to CPC land

Post by rubber_jonnie »

Icky wrote: Sun Nov 05, 2023 4:31 pm Pull-ups in the joystick may be?
So I pulled the cover off all my sticks and had a look. None have pull ups of any sort and are all (bar the Sega) simply switches wired to the plug.

The Competition Pro is simply microswitches, as it the Cheetah Mach +. I realised just now that the Cheetah in fact works fine with the autofire turned off, I must have missed that the other day, and in fact internally it is very similar to the Competition Pro, so that's a bonus.

The Mega Drive Game Pad has some sort of glop top inside, so I will rule that out right away.

That leaves the Atari Pro line stick and 7800 joypad. These use the 'clicky domes' like this:

Screenshot 2023-11-05 at 17.16.25.png
Screenshot 2023-11-05 at 17.16.25.png (538.22 KiB) Viewed 96 times

And both have 2 fire buttons that work with Atari's. It makes me wonder if they act as capacitors in some way that the different joystick circuit of the CPC sees as a connection, but isn't detected on other machines.

I did just find a stick I forgot about at the bottom of my quick use storage, so will go and try that too.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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rubber_jonnie
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Re: Off for a trip to CPC land

Post by rubber_jonnie »

Ok, weird.

The joystick I just found is branded 'Discwasher' and isn't really much more than an upmarket 3rd party Atari CX40 stick, and uses the same clicky domes as the other Atari sticks.

Only it doesn't exhibit the same behaviour and works just fine. Go figure...
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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