Superfo Cartridge Interface

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andyconnelly
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Superfo Cartridge Interface

Post by andyconnelly »

Hi,

I am trying to locate the design files for Superfo's (schematic and PCB) for Superfo's ROM cartridge and kempston interface. There is a fleeting mention of it here: viewtopic.php?f=21&t=2659&start=40

Can anyone point me in the right direction ? I have searched the site but no luck so far.

Thanks.
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1024MAK
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Re: Superfo Cartridge Interface

Post by 1024MAK »

The connections to the cartridge slot will be the same as the Sinclair Interface 2 (see here).
I expect the push button switch to simply be a reset switch wired between the /RESET line and 0V/GND.

The joystick port will be wired to the Atari pin-out, and the Kempston I/O protocol (input on port 31) using a 74xx366 (74LS366 / 74HC366 / 74HCT366 ) chip and some 1N4148 diodes. Here is a schematic for one version.

A more modern (and better) design is in this post.

Mark
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andyconnelly
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Joined: Sat Feb 15, 2020 10:56 pm

Re: Superfo Cartridge Interface

Post by andyconnelly »

Hi Mark,

Thanks for the reply - and for the links. It's good to see the diffences in the kempston implementations.

It would be good to find a PCB design that I can add to my current JLCPCB order. I am particularly interesed in a ROM slot interface to try a few things out. Do you know of any Gerber or Eagle design files available ?

Thanks.
McKlaud
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Re: Superfo Cartridge Interface

Post by McKlaud »

No, they are not. It was not an open project. Please see SMR where superfo sells them. If can't find any, send me a PM, because I've got one spare PCB if you are interested.
Claudius
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1024MAK
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Re: Superfo Cartridge Interface

Post by 1024MAK »

andyconnelly wrote: Sun Feb 16, 2020 5:18 am Hi Mark,

Thanks for the reply - and for the links. It's good to see the diffences in the kempston implementations.

It would be good to find a PCB design that I can add to my current JLCPCB order. I am particularly interesed in a ROM slot interface to try a few things out. Do you know of any Gerber or Eagle design files available ?

Thanks.
I don’t know of any PCB design files that are available.

On the second hand market there are three different combined joystick and cartridge interfaces from back in the day (the first one of course being Sinclair’s Interface 2), the others being the RAM Turbo and Kempston’s Pro design (I have one and one day I intend to reverse engineer it).

With regards to the joystick interface, there are actually at least six different circuit designs (probably more) to implement the Kempston joystick interface. Kempston themselves used at least three different circuits, and there were many “clones”.made by other companies.

The cartridge slot itself needs no electronic components, as it is just a sub set of the connections already available on the expansion bus / edge-connector.

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
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1024MAK
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Re: Superfo Cartridge Interface

Post by 1024MAK »

SMR = SellMyRetro

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
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