Acorn A500
Acorn A500
Hi
I am new here so I hope I am in the right place.
I am going to be going through my acorn kit , doing power supplies & it looks like motherboards to thanks to battery leaks, anyway starting with my A500 done the caps in PSU and it turns on and boots now , revolving screen * in supervisor mode everything white is actually pink now, I need to get a mouse sorted any idea's on it I have an AMX mouse that I could convert but need a plug and pin connections, I also need to get it to boot from Hard Drive, I have also took pictures as I have stripped it down, I do know that it is running RiscOs 3
Now fitted new batteries and repaired battery holder, now a live wire has broken to the hard drive where something is inserted into it and shrink wrapped writing on it RS 2*2 2.2A there is not much there to solder to can you tell me what it is and where to get another one please.
Thanks for any help you can give me
Raymond
I am new here so I hope I am in the right place.
I am going to be going through my acorn kit , doing power supplies & it looks like motherboards to thanks to battery leaks, anyway starting with my A500 done the caps in PSU and it turns on and boots now , revolving screen * in supervisor mode everything white is actually pink now, I need to get a mouse sorted any idea's on it I have an AMX mouse that I could convert but need a plug and pin connections, I also need to get it to boot from Hard Drive, I have also took pictures as I have stripped it down, I do know that it is running RiscOs 3
Now fitted new batteries and repaired battery holder, now a live wire has broken to the hard drive where something is inserted into it and shrink wrapped writing on it RS 2*2 2.2A there is not much there to solder to can you tell me what it is and where to get another one please.
Thanks for any help you can give me
Raymond
Re: Acorn A500
Wowsers. Never seen a real A500. There must only be a handful ever made.
Re: Acorn A500
Ah. You mean R260? I've seen those. Never seen an A500
Re: Acorn A500
Wow, The Centre For Computing History suggests they were internal dev machines that were never sold to the public.
Hope you can fully revive it.
There's some interesting info here: https://chrisacorns.computinghistory.or ... /A500.html
Hope you can fully revive it.
There's some interesting info here: https://chrisacorns.computinghistory.or ... /A500.html
Re: Acorn A500
Thanks for the link I now know what the mouse looks like but cannot find it anywhere.Ronin47 wrote: ↑Sat Mar 16, 2024 9:31 am Wow, The Centre For Computing History suggests they were internal dev machines that were never sold to the public.
Hope you can fully revive it.
There's some interesting info here: https://chrisacorns.computinghistory.or ... /A500.html
I suspect it might have come with a ps2 mouse as there is a ps2 socket on the front panel.
Re: Acorn A500
A500s had a quadrature mouse input on the keyboard. See http://chrisacorns.computinghistory.org ... board.html
That socket looks like an aftermarket add-on. Is there a podule to support it?
That socket looks like an aftermarket add-on. Is there a podule to support it?
Miserable old curmudgeon who still likes a bit of an ARM wrestle now and then. Pi 4, 3, ARMX6, SA Risc PC, A540, A440
Re: Acorn A500
It's easy enough to make an adapter, this is the one I made when imaging this machine - https://www.domesday86.com/?page_id=936
I'm sure you can find the standard arc mouse pinout.
Re: Acorn A500
Looks like it's wired straight onto those resistors on the PCB. I don't think it's a mouse port despite the connector...SKS1 wrote: ↑Sat Mar 16, 2024 11:20 am A500s had a quadrature mouse input on the keyboard. See http://chrisacorns.computinghistory.org ... board.html
That socket looks like an aftermarket add-on. Is there a podule to support it?
Re: Acorn A500
Yes it looks that way to me , it is wired to the board inside. the wires goto the resisters bellow in the picture.SKS1 wrote: ↑Sat Mar 16, 2024 11:20 am A500s had a quadrature mouse input on the keyboard. See http://chrisacorns.computinghistory.org ... board.html
That socket looks like an aftermarket add-on. Is there a podule to support it?
Re: Acorn A500
Hi seen this online and thinking of connecting to one of these number 1 looks the best to me what do you think ?IanS wrote: ↑Sat Mar 16, 2024 11:49 am It's easy enough to make an adapter, this is the one I made when imaging this machine - https://www.domesday86.com/?page_id=936
IMG_20171014_145111243_HDR.jpg
a5000-mouse-connector.PNG
I'm sure you can find the standard arc mouse pinout.
Re: Acorn A500
No the only podule seems to be something to do with internetSKS1 wrote: ↑Sat Mar 16, 2024 11:20 am A500s had a quadrature mouse input on the keyboard. See http://chrisacorns.computinghistory.org ... board.html
That socket looks like an aftermarket add-on. Is there a podule to support it?
Re: Acorn A500
just tried my RiscPc keyboard but that did not work
Re: Acorn A500
RISC PC keyboards are PS/2 where earlier ones are not (proprietary, so always been expensive).
Last edited by SKS1 on Sat Mar 16, 2024 7:11 pm, edited 1 time in total.
Miserable old curmudgeon who still likes a bit of an ARM wrestle now and then. Pi 4, 3, ARMX6, SA Risc PC, A540, A440
- BeebMaster
- Posts: 7433
- Joined: Sun Aug 02, 2009 5:59 pm
- Location: Lost in the BeebVault!
- Contact:
Re: Acorn A500
Ah, it has a Master 128 PSU.razz177 wrote: ↑Sat Mar 16, 2024 4:55 pmNo the only podule seems to be something to do with internetSKS1 wrote: ↑Sat Mar 16, 2024 11:20 am A500s had a quadrature mouse input on the keyboard. See http://chrisacorns.computinghistory.org ... board.html
That socket looks like an aftermarket add-on. Is there a podule to support it?
I heard about some early Archimedes using the Master power supply but I don't think I've ever seen one.
Re: Acorn A500
i worked on a 310 (or was it a 440 !) that had a master psu (i think) at the fixathon at tnmoc in november.BeebMaster wrote: ↑Sat Mar 16, 2024 5:52 pmAh, it has a Master 128 PSU.razz177 wrote: ↑Sat Mar 16, 2024 4:55 pmNo the only podule seems to be something to do with internetSKS1 wrote: ↑Sat Mar 16, 2024 11:20 am A500s had a quadrature mouse input on the keyboard. See http://chrisacorns.computinghistory.org ... board.html
That socket looks like an aftermarket add-on. Is there a podule to support it?
I heard about some early Archimedes using the Master power supply but I don't think I've ever seen one.
never seen another like it lol
-Elliot
Lover of all things acorn, but especially the 8 bits!
- bbc b issue 7 with econet- electron issue 2 - microvitec cub 653 - a420/1 -
i like to use as much original hardware as possible, and only use disk and tapes!
Lover of all things acorn, but especially the 8 bits!
- bbc b issue 7 with econet- electron issue 2 - microvitec cub 653 - a420/1 -
i like to use as much original hardware as possible, and only use disk and tapes!
Re: Acorn A500
All A500's had a slightly modified Master PSU. The modification was to add a yellow wire for the 12V supply, which is normally only available on the aux connector on a Master.
You can see the extra wire here - https://www.domesday86.com/wp-content/u ... _rear2.jpg
Re: Acorn A500
Re: Acorn A500
Yes mine has the yellow wire it is obvious that it has been put in afterwards as it has a different spade terminal.IanS wrote: ↑Sat Mar 16, 2024 7:37 pmAll A500's had a slightly modified Master PSU.
a500-psu.PNG
The modification was to add a yellow wire for the 12V supply, which is normally only available on the aux connector on a Master.
You can see the extra wire here - https://www.domesday86.com/wp-content/u ... _rear2.jpg
Re: Acorn A500
Well that was strange followed the link and saw the serial number of 249 and mine is 250.razz177 wrote: ↑Sat Mar 16, 2024 9:10 pmYes mine has the yellow wire it is obvious that it has been put in afterwards as it has a different spade terminal.IanS wrote: ↑Sat Mar 16, 2024 7:37 pmAll A500's had a slightly modified Master PSU.
a500-psu.PNG
The modification was to add a yellow wire for the 12V supply, which is normally only available on the aux connector on a Master.
You can see the extra wire here - https://www.domesday86.com/wp-content/u ... _rear2.jpg
Re: Acorn A500
I Have managed to find a mouse that works, after I ordered parts oh wellIanS wrote: ↑Sat Mar 16, 2024 11:49 am It's easy enough to make an adapter, this is the one I made when imaging this machine - https://www.domesday86.com/?page_id=936
IMG_20171014_145111243_HDR.jpg
a5000-mouse-connector.PNG
I'm sure you can find the standard arc mouse pinout.
Re: Acorn A500
Re: Acorn A500
Not too surprised, as it may be an A500 build of RISC OS that does not support the quite-different Archimedes keyboard protocol.
In RISC OS 2 there were global variables A500Keyboard and A1Keyboard (Archimedes) that could control the variant being built.
Miserable old curmudgeon who still likes a bit of an ARM wrestle now and then. Pi 4, 3, ARMX6, SA Risc PC, A540, A440
Re: Acorn A500
Interesting, I hadn't realised the keyboard protocol was different.
From the post in the other thread, it looks to be a standard 3.10 rom, so curious how it works with the different keyboard
viewtopic.php?p=420163#p420163
From the post in the other thread, it looks to be a standard 3.10 rom, so curious how it works with the different keyboard
viewtopic.php?p=420163#p420163
It looks like the FDC is different in the A500, is it compatible with the 1770?
Re: Acorn A500
See "F0" in https://www.binarydinosaurs.co.uk/Museu ... ellows.php. This story actually related to when we received the first Archimedes protocol keyboard. A500 one just worked pretty quickly, but the Arc one had been outsourced.
If they were still supporting A500s, which clearly they must still have been doing, I think it was possible to build a kernel that supported either keyboard.IanS wrote: ↑Wed Mar 20, 2024 1:13 pm From the post in the other thread, it looks to be a standard 3.10 rom, so curious how it works with the different keyboard
viewtopic.php?p=420163#p420163
Would have made sense to build an A500 image at the same time as all the other 3.1 images for A310 thru A5000.
Don't think so? Not my area. Haven't see the A500 circuit diagram since 1988 . It did have a higher density mode that we never got to work reliably.
Miserable old curmudgeon who still likes a bit of an ARM wrestle now and then. Pi 4, 3, ARMX6, SA Risc PC, A540, A440
Re: Acorn A500
We already have an A500 RISC OS 3.10 (30 Apr 1992) ROM dump that is definitely different from the standard Archimedes RISC OS 3.10, it came from an A500 with serial #47, see viewtopic.php?p=333017#p333017.IanS wrote: ↑Wed Mar 20, 2024 1:13 pm From the post in the other thread, it looks to be a standard 3.10 rom, so curious how it works with the different keyboard
viewtopic.php?p=420163#p420163
It looks like the FDC is different in the A500, is it compatible with the 1770?
- Nigel
BBC Model B: ATPL Sidewise, Acorn Speech, 2xWatford Floppy Drives, AMX Mouse, Viglen case, BeebZIF, etc.
BBC Model B: ATPL Sidewise, Acorn Speech, 2xWatford Floppy Drives, AMX Mouse, Viglen case, BeebZIF, etc.
Re: Acorn A500
The FDC on the A500 was either 9793 or 1793 according to the TRM I think.