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My old Atom for you to see

Posted: Sun Mar 08, 2020 6:01 pm
by highfell
Seeing this forum has encouraged me to get my Two Atoms out of the attic.

I bought my Acorn Atom in my year off before Uni in 1980/81. I still have it but unfortunately it doesn’t seem to work now. It was a simple machine with no extras but it did have the 12K of RAM. The PCB looks clean with no apparent horrors , so I don’t know why the Acorn doesn’t power up.

However when I left Uni, I saw an advert for a machine that had a disk drive. This machine does work -:) but although the disk drive spins , it can’t read disks anymore.

The machine comes with the FP rom, the Timedata 16K memory board , a printer interface , the DOS interface and disk drive,

It also a programmable EPROM using a HM6116 chip . There is a switch which I have checked still works such that it the chip has power going to it then you can write data to it , otherwise you can’t and it protects the data on it. I have done the signature check on it and it comes back with 2B60, so I don’t know it it has a ROM program in it or not.

I would like to load some ROMs into the current EPROM but not sure how to ? I don’t have a cassette tape recorder any more.

As regards the MMC board, I have been in touch with Charlie and it seems that it would sense to buy one.

It looks like there is the PL8 socket as there are soldered pins on the other side of the PCB board and also LK3 looks similar. I have yet to photograph the keyboard side of the PCB board.

However, I am nervous about removing the EPROM chip to replace with the MMC EPROM because it has the power wires going to it and I don’t want to harm my Acorn Atom.

Here are the pictures of my working Atom . Comments welcomed.

PS - edited the CRC code to 2B60

Re: My old Atom for you to see

Posted: Sun Mar 08, 2020 6:17 pm
by Multiwizard
Hi,

thanks for the pics, it´s always nice to see Atoms... :D

About the Atom that doesn't power up,, does it beep when you press Ctrl+G ?


Greetings, Wim... :-)

Re: My old Atom for you to see

Posted: Sun Mar 08, 2020 10:50 pm
by roland
Don't worry about any data in the HM6116 .... There is nothing in it. The HM6116 is static cmos memory and its contents is gone directly after power off unless you have some battery backup implemented but that is not applicable here. So you can safely remove it and replace it by the AtoMMC rom.

I also suggest to install a modern memory board from Prime or a Yarrb board. Then you can play allmost all the games and run other memory consuming programmes from the software archive.

To get your Atom back to work, just try to bring it back to its original state with 8K rom and 2K ram and then start fault finding. Start with checking the power supply, does each IC get about 5V?

Don't fear, it's an Atom so we can get it back working again :D

Re: My old Atom for you to see

Posted: Mon Mar 09, 2020 5:30 pm
by cjm
(Apologies for hijacking this thread but I can't send a PM)

Where can I obtain an AtoMMC and a yarrb board for my atom?

Kind regards

Re: My old Atom for you to see

Posted: Sun Mar 22, 2020 2:39 pm
by eXne
The Yarbb is designed and manufactured by Roland.
See: viewtopic.php?f=44&t=18020&start=60#p255834

Cheers,

Etienne

Re: My old Atom for you to see

Posted: Sun Mar 22, 2020 2:42 pm
by roland
I already contacted Chris by email, he will receive his Yarrb board within a few days.

Re: My old Atom for you to see

Posted: Thu Mar 26, 2020 7:45 pm
by cjm
roland wrote:
Sun Mar 22, 2020 2:42 pm
I already contacted Chris by email, he will receive his Yarrb board within a few days.
I have received my Yarrb board, it's up and running 8) - thank you

Re: My old Atom for you to see

Posted: Thu Mar 26, 2020 7:49 pm
by roland
Good to hear that it works - but I didn't expect otherwise :mrgreen:
After all it was build and tested. Enjoy your memory board!

Re: My old Atom for you to see

Posted: Sat Mar 28, 2020 10:45 pm
by highfell
Multiwizard wrote:
Sun Mar 08, 2020 6:17 pm
Hi,

thanks for the pics, it´s always nice to see Atoms... :D

About the Atom that doesn't power up,, does it beep when you press Ctrl+G ?


Greetings, Wim... :-)
Hiya - no sound when I press Ctrl G sadly

Re: My old Atom for you to see

Posted: Tue May 05, 2020 9:05 pm
by highfell
roland wrote:
Sun Mar 08, 2020 10:50 pm
Don't worry about any data in the HM6116 .... There is nothing in it. The HM6116 is static cmos memory and its contents is gone directly after power off unless you have some battery backup implemented but that is not applicable here. So you can safely remove it and replace it by the AtoMMC rom.

I also suggest to install a modern memory board from Prime or a Yarrb board. Then you can play allmost all the games and run other memory consuming programmes from the software archive.

To get your Atom back to work, just try to bring it back to its original state with 8K rom and 2K ram and then start fault finding. Start with checking the power supply, does each IC get about 5V?

Don't fear, it's an Atom so we can get it back working again :D
I removed the HM6116 and discovered that in fact it not one chip but three piggy backed on top of each other. Two of a similar size (2x HM 6116 ?) plus a smaller one at the bottom. Seems rather unusual to me.

Please see the pics - does anyone know why ?

Re: My old Atom for you to see

Posted: Tue May 05, 2020 9:12 pm
by roland
The 6116 is 2k * 8 (bits). This is placed in socket 24, the utility ROM socket. The purpose of this is to have 4k RAM at #Axxx so you can load any utility rom you want instead of switching eproms. The small IC is probably a 74LSxx that selects one of the 6116's based on A11 and CS.