An unknown Acorn Atom Clone found?

discussion of games, software, hardware & emulators relating to the Acorn Atom and Acorn System machines.
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carlosanta
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An unknown Acorn Atom Clone found?

Post by carlosanta » Tue Jul 31, 2018 9:36 pm

Hello,
I'm a computer history researcher and I'm working in documenting italian computer history.
There is a rare italian home computer model, the SHINE-1, that was made by Lorenzon Elettronica (Venice) in 1983.
Here is a link of a scanned adv from italian computer magazine (Elettronica 2000, november 1983 issue)
http://www.ignaziovendola.it/images/fot ... ov1983.jpg
Looking into it's hw characteristics I've noticed that are actually the same of the ACORN ATOM.
6502 processor, 16k RAM and the Motorola 6847 for video output.
I've attached some photos of the computer and its internals.
Since today my idea (that the Shine 1 is an Atom clone) was only a supposition, but this month a friend of mine has recovered a SHINE1 and dumped its roms! I've tried to look into and understand if this code is compatible with the ATOM but I do not know the Atom architecture enougth, I've tried to load the roms into an Atom Emulator (Atomulator) but I've failed and so I'm here in search for help.
Anyone that can look into this roms dump and confirm that the hw architecture is the same?
Maybe it's possible to load and run a SHINE1 Emulator using am Atom Emulator?
I'm attaching the eproms dump, thanks for anyone that can help!
Attachments
SHINE1_EPROM_DUMP.ZIP
(18.11 KiB) Downloaded 28 times
37327795_10156467694756664_6693581839325462528_o.jpg
37324704_10156467699211664_4328961240593334272_o.jpg
37323267_435388173644883_6803631258069893120_n.jpg
37313560_10156467696591664_521370435158278144_o.jpg
37307353_435388256978208_2034403352439160832_n.jpg
37307340_435388216978212_3415493109155364864_n.jpg

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Pernod
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Re: An unknown Acorn Atom Clone found?

Post by Pernod » Wed Aug 01, 2018 12:24 am

I've taken a quick look at getting this running in MAME. It is not an Atom clone.

The memory map looks something like:
0000-3fff RAM 16K
6800-7fff VIDEO RAM
9400-940f 6522 VIA
9800-980f 6522 VIA
9c00-9c03 1771 FDC
b000-bfff ROM IC58
c000-cfff ROM IC59
d000-dfff ROM IC62
e000-efff ROM IC61
f000-ffff ROM IC60

The machine is running but I don't have any video output yet. If it used a 6845 rather than the 6847 then I'd probably make quicker progress. It's currently stuck writing to the 6522 port B which I'm guessing is controlling the 6847.

Can you provide any more details, photos of whole board, any manuals, expansion ports, etc?
Last edited by Pernod on Mon Nov 26, 2018 2:40 pm, edited 3 times in total.
- Nigel

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carlosanta
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Re: An unknown Acorn Atom Clone found?

Post by carlosanta » Wed Aug 01, 2018 9:28 am

Thankyou very much Nigel!
Unfortunately I do not have any documentation, but I'm managing to find and scan them.
In the meantime I can attach some other photos of maniboard and the back with ports (consider that those photos came from two models of the SHINE1.
Attachments
37637312_2093970394159112_3748051138394456064_n.jpg
37633144_2093969887492496_1941322829790183424_n.jpg
37599858_2093970184159133_7290425733321588736_n.jpg
37584926_2093970610825757_6322679982745190400_n.jpg
37537741_435388303644870_828333053473456128_n.jpg
37427708_2092405254315626_3654709438784208896_o.jpg
37345075_10156467695441664_2618231275030315008_o.jpg

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Re: An unknown Acorn Atom Clone found?

Post by Pernod » Wed Aug 01, 2018 11:01 am

carlosanta wrote:
Wed Aug 01, 2018 9:28 am
In the meantime I can attach some other photos of maniboard and the back with ports (consider that those photos came from two models of the SHINE1.
Thanks, but I'll need better photos than those. I need to be able to read and identify all components, including any crystals.
- Nigel

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roland
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Re: An unknown Acorn Atom Clone found?

Post by roland » Wed Aug 01, 2018 2:28 pm

Well, they did a very good job on copying the Atom's keyboard :mrgreen:
The only differences are:
  • RET and DEL are swapped
  • BREAK key missing (reset is at the back which might be an advantage :lol:
Other items not on the Atom are the serial port and the disk interface connector. Nice computer anyway.
256K + 6502 Inside
MAN WOMAN :shock:

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Re: An unknown Acorn Atom Clone found?

Post by Kazzie » Wed Aug 01, 2018 3:03 pm

From the advert: "Grafica multimodo 49.152 pixel" - 49.152 pixel multimode graphics? What's that when it's at home?

At first I was suspecting that just below 50hz it might be a PAL TV-related frequency (actually thinking of NTSC: 59.94Hz), but the only mention I can find of it as a frequency is as a reference clock for Firewire. :shock:

On the other hand, maybe it's 49 rows and 152 columns of pixels on a TV screen. But that's less exciting.
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Re: An unknown Acorn Atom Clone found?

Post by roland » Wed Aug 01, 2018 3:10 pm

Kazzie wrote:
Wed Aug 01, 2018 3:03 pm
From the advert: "Grafica multimodo 49.152 pixel" - 49.152 pixel multimode graphics? What's that when it's at home?
It's just 256 x 192 pixels (like the Atom CLEAR4) :)
Last edited by roland on Wed Aug 01, 2018 3:11 pm, edited 1 time in total.
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Re: An unknown Acorn Atom Clone found?

Post by Kazzie » Wed Aug 01, 2018 3:23 pm

Ah, the continental style of denoting thousands with a period rather than a comma!

So that's 49,152 pixels (or 49kilopixels) in our notation.
BBC Model B 32k issue 7, Sidewise ROM board with 16K RAM
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Re: An unknown Acorn Atom Clone found?

Post by roland » Wed Aug 01, 2018 3:30 pm

Yep. 49 kilopixels.

It really would be nice to find some more documentation of this system because it might be possible to run the roms on the Atom2k15. Well, at least partly. I should find out where the 6847 is set up and how the keyboard is scanned. And then, with one ROM at #Axxx and the rest at #C000 - #FFFF (like BBC Basic) it might work :)

There is very little documentation of this computer on Google :(
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Re: An unknown Acorn Atom Clone found?

Post by carlosanta » Mon Aug 06, 2018 8:06 am

Hello, here it is some photo in high-resolution, hope it can help!
Thankyou!
https://www.dropbox.com/s/drfp4jvx7qdg9 ... 1.zip?dl=0

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Re: An unknown Acorn Atom Clone found?

Post by Kazzie » Mon Aug 06, 2018 11:09 am

Those pictures are better, but some chips are still difficult to read. (You've taken some good pictures of the overall board, six or eight close-up pictures of different parts of the board to get the component numbers would complement these pictures and help us identify everything. Try to photograph them perpendicularly (at 90 degrees) so that every part of the picture is in focus. If you know somebody who owns a DLSR camera, it may be worth borrowing it, as it will take clearer pictures than a mobile phone.)

Looking at the pictures, I can see that the floppy disk controller is a 1771B-01. Acorn used Intel's 8271 in the System, Atom and early BBCs. It has a 6502A and 6522A, suggesting we're looking at 2MHz operation, but I can't see a crystal anywhere near the 6502. It looks like there are a pair of 6522s toward the back, which would be similar to the BBC Micro. I think the left one is used for the keyboard and serial port, and the right one is used for the parallel port, and possibly the expansion bus on PL10. (I can't make out whether PL10 is connected to the 6522 or direct to the CPU's address/data bus.)

There are sixteen TMS4116-15 DRAM chips in the lower left had corner, at 16x1Kbit each that makes for a total of 32kilobytes of RAM. The advert posted up-thread only listed 16kB; perhaps it was sold with eight chips and was then expanded like a BBC Model A? All sixteen chips are socketed, and there are two different date codes used: seven have 811, nine have 8144.

In fact, on further exploration, one of the older pictures shows the top row IC13-20) soldered to the board, with IC21-28 socketed. It seems that the later photos show a board that has been repaired due to a RAM failure, and expanded at the same time.

Several of the 7400 series "glue" chips look to be old stock: ICs 29, 30, and 35 have 1977 date codes on them, IC 38 and 39 are 1979, whereas the sixteen 4116 DRAM chips are all dated 1981.

Comparing the photos from the two machines, it seems that the expansion board in the top left corner is placed in the MC6847's socket, has the MC6847 replaced on the board, with some LM319 comparators and other chips nearby before exiting the back above the serial port. At first I assumed that this was related to the serial port, but as it's connected to the 6847, it must be a video card. It has a LM 1889 TV modulator at the rear end. There's also one under the board near the original video output, suggesting that this board replaces the video output, but I can't see any extra RAM on this board (whereas I think there was extra video RAM for the Atom's colour TV card). The wide flat connection at the back intrigues me.

What is the vertical expansion board between the 6502 and the RAM? I'd day it looks like a third party add-on from its colouration (and the fact it seems to be connected by lots of flying wires). A picture of the front of it would be interesting.
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Re: An unknown Acorn Atom Clone found?

Post by Pernod » Mon Nov 26, 2018 1:40 pm

Decided to take another look at this, and made a little progress...
0004.png
I had the video RAM in the wrong place, it's actually at 0x6800-0x7fff, and it's mapped backwards so top left of screen starts at 0x7fff and counts down. Now need to figure out the keyboard.

Hope the OP returns at some point.
Last edited by Pernod on Mon Nov 26, 2018 1:41 pm, edited 1 time in total.
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Re: An unknown Acorn Atom Clone found?

Post by Kazzie » Mon Nov 26, 2018 3:40 pm

Nicely done!

Looking at the Dropbox pictures posted above, it looks like the keyboard is built as an 8x8 matrix. Three lines are decoded into eight rows by a 74ls138, and there are eight other lines that would seem to serve as columns (though two of those are also connected to the thirteen diodes visible). Unfortunately the motherboard traces for the keyboard connector appear to be on the underside, but I'd suspect they connect to the nearby 6522 in some manner.

On a lighter note, when I read this thread I can't help thinking of this song, thanks to my young kids' viewing tastes. :roll:

Edit: here's the keyboard pinout from what I see (numbered left-right):
1-3: 5V (on 74ls138), speaker, Transistor T1 R1-8 bottom
4-7: 0V (on 74ls138), T1
8: T1, and via R9 to speaker
9: keys?
10-12: 74ls138 ABC
13-18: keys, top of R8-3 respectively
19: keys?, D7-10,D12,14,15,18 top, R2 top
20: keys?, D6,D11,D13,16,17 top, R1 top
Last edited by Kazzie on Mon Nov 26, 2018 4:04 pm, edited 2 times in total.
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Re: An unknown Acorn Atom Clone found?

Post by Pernod » Tue Nov 27, 2018 11:50 am

You were right about the keyboard having an 8x8 matrix. The row is written to VIA PB bits 0-2 and key status is read from VIA PA. I have the majority of keys correctly mapped, row 0 seems to only have CTRL and SHIFT with other 6 bits unused. Rows 1-6 are alpha-numeric and row 7 has COPY, RET, DEL, REPT, LOCK, and cursor keys. Not sure on the behaviour of COPY, REPT, LOCK though so may be incorrect.

Also corrected the inverse video which is bit 7 of video RAM, fixes cursor. Without a manual I have no idea how to select graphics modes so is highly likely the 6847 is not fully controlled.

The 1771 FDC is mapped at &9C00 but without any software/floppy images can go no further with this. Performing a DIR tries to write to &9D00 and read from &9E00, suspect &9D00 could be a latch.

Hooking up the serial port to the other VIA should be easy, but without knowing how to access it from BASIC is pointless.

The machine doesn't complain when I issue a SOUND command, so maybe able to get it to make some noise. I didn't see any particular sound hardware in the photos, maybe a beeper like the Electron? Will see if I can trace what CTRL-G does.

Overall, I think I'm almost done with this. Without a manual and software any more is just guesswork with no idea of correct behaviour.
0005.png
0006.png
Last edited by Pernod on Tue Nov 27, 2018 1:16 pm, edited 1 time in total.
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Re: An unknown Acorn Atom Clone found?

Post by BigEd » Sun Dec 09, 2018 6:31 pm

Is this a unique and novel version of BASIC? I notice it has a JPERR command, for example, not sure I've seen that before.

Edit: I see there's an early mention in the press in 1981 where the machine is expected to be launched in Jan '82 at 600 thousand lira. See p14 of issue 3 of MCmicrocomputer:
https://issuu.com/adpware/docs/mc003/85
SHINE-1981.png
Last edited by BigEd on Sun Dec 09, 2018 6:37 pm, edited 4 times in total.

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