FGC company history ?

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iss
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Re: FGC company history ?

Post by iss »

Steve, thanks for DSK images.
I found that all communication programs in both DSK files are using serial interface at starting address #380.
Than I added option to Oricutron to be able to specify ACIA start address - and both programs started to work (or kind of...).
Here is my question: Does anyone know about such 'standard' serial interface for Oric which uses the addresses #380..#383?
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Steve M
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Re: FGC company history ?

Post by Steve M »

The Oric Modem came with an RS232 interface.

The attached circuit was obtained by the authors of Oricomms. Trevor Shaw wrote a few articles for OUM about using the serial port which I could scan, if you're interested.
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rs232 circuit001.jpg
Godzil
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Re: FGC company history ?

Post by Godzil »

Steve M wrote:The Oric Modem came with an RS232 interface.

The attached circuit was obtained by the authors of Oricomms. Trevor Shaw wrote a few articles for OUM about using the serial port which I could scan, if you're interested.
The schematic is fairly classic, but even if there are this 7404 (F?) on the TxD/RxD and other control line for the RS232 port, never use this directly, it will need a proper RS232 buffer like a MAX232 or you will kill the 7404 buffer or worse the 6551 (RS232 voltage are

-3V to -25V for a logical 1
+3 to +25 for a logical 0

Even if most modern device use voltages close to -3/+3V, the 6551 is not made support negative voltages, and not that high positive voltage. I don't know which 7404 they where using, but a "7404" without something between "74" and "04" would meen TTL, and the voltage is basically 0V to +5V.

So if someone want to build this, do not use the 7404 on the RS232 IO line and use a proper MAX232, it will save your day.
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ibisum
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Re: FGC company history ?

Post by ibisum »

I am very interested in all things Oric+Modem/RS232! I will build this.
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Steve M
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Re: FGC company history ?

Post by Steve M »

All I know is that is supposed to the the actual circuit used by Oric which seem to have worked OK for those that actually had the modem.
Last use I'm aware of was when the Oricall BBS system was on the go in the nineties. I don't have the PC software needed to set up a BBS. Nick Howarth, (son of Jonathan Haworth) was the person that ran it. I didn't have a cable to allow the modem and disk drive to be attached at the same time so was never able to use it.

7404f seems to be a 'flatpack' version - so maybe it fitted in the small case better(?) I don't have any details as to whether it has any letters in between
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7404datasheet.pdf
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iss
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Re: FGC company history ?

Post by iss »

Thanks for all that info!
I wanted to collect all available communication software for Oric
and to find out what hardware is needed to run these programs.
So far software is:
- barnsey123: HNEFATAFL-ONLINE.dsk - #31C, #320
- Vagelis Blathras: MODEM.dsk - #31C, #320, #340
- Fabrice Francès: Tea For Two - #31C, #320
- ORICALL.dsk - #380
- ORICOMMS.dsk - #380
and the hardware:
- TheOric #15 page 43 - #380
- André Majorel's MIDI/serial interface - #380
- Muso's ;) ORIC Site - #380
- DIY serial interface - #031C and #039C
- Extensions to build for your Oric Atmos - #3FC
Currently I'm working on new communication extension for Oric and I hope to announce it here soon...
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ibisum
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Re: FGC company history ?

Post by ibisum »

iss: count me as extremely interested! For my needs, it'd be enough to be able to wire up a small set of Atmos's to a raspberry-Pi with multiple USB/Serial adapters, and then just give everyone a login prompt. ;)

Looking forward to your proposal...
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Steve M
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Re: FGC company history ?

Post by Steve M »

Ha. I'd forgotten I had a serial interface diagram online. That is the redrawn version of the hand-drawn version I posted. I think the neater version was used in either CEO or OUM.
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Steve M
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Re: FGC company history ?

Post by Steve M »

I've made a pdf of the Trevor Shaw articles but it's too big to go on here - 10Mb. Send me your email (if it'll accept 10Mb).

Here's an article/letter about the modem.
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modem letter.pdf
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