ARM1 versions / batches

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firthmj
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ARM1 versions / batches

Post by firthmj » Tue Dec 18, 2018 4:26 pm

Hi,

Does anyone have any information on how many ARM1 chips were produced, or in how many batches?

Most of pictures I have been able to find have been of the same batch of chips, dated week "8625", and labelled "AUTUMN" (is that a code name or a season?)

This includes the ARM evaluation picture on Wikipedia:

https://en.wikipedia.org/wiki/ARM_archi ... System.jpg

And all but one of the ARM chips in the various boards that Ed posted pictures of here:

viewtopic.php?f=32&t=13379&p=174900#p174900

Interestingly, if I am reading it right, what should be the oldest board (the 1MB one with mod wires at the top of the group) has a younger ARM1 CPU than the rest (date code 8634)

My next question is about the A500 computer (not to be confused with the A500 second processor). I originally had the impression that this would have had an ARM1, but the older instance described at Chris's Acorns has an ARM2:

http://chrisacorns.computinghistory.org ... /A500.html

Were all of them at least ARM2, or were there early ones that had ARM1s fitted?

And finally, after some rambling, the point of my post!

There seems to be two instances of "engineering sample" versions of the ARM1 that have been seen, which presumably are the original 1985 ones, rather than the later "production" run.

The first is in Dave M's pre-production ARM evaluation unit, which has been on loan to various people, and currently is residing with me. The ARM in this looks like this:
arm_eval_es_crop.jpg
ES ARM1
Other images of the same unit are on Beebmaster's site here:

http://www.beebmaster.co.uk/Shows/ARMSecond.html

I thought this was the only instance of this flavour of the CPU that had been mentioned online, but today I found a reference to another chip, "in a box at the Centre for Computing History":

viewtopic.php?f=3&t=13223&p=173205#p173205

So my question is whether anyone knows of any other instances of the "engineering sample" silicon, and whether any of them are running in any boards / systems?
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SarahWalker
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Re: ARM1 versions / batches

Post by SarahWalker » Tue Dec 18, 2018 6:59 pm

firthmj wrote:
Tue Dec 18, 2018 4:26 pm
Most of pictures I have been able to find have been of the same batch of chips, dated week "8625", and labelled "AUTUMN" (is that a code name or a season?)
Codename.
My next question is about the A500 computer (not to be confused with the A500 second processor). I originally had the impression that this would have had an ARM1, but the older instance described at Chris's Acorns has an ARM2:

http://chrisacorns.computinghistory.org ... /A500.html

Were all of them at least ARM2, or were there early ones that had ARM1s fitted?
I believe most if not all A500s were fitted with ARM1s initially. Most would have been upgraded to ARM2 so they could still be used as development machines, with some having prototype ARM3s.
I thought this was the only instance of this flavour of the CPU that had been mentioned online, but today I found a reference to another chip, "in a box at the Centre for Computing History":

viewtopic.php?f=3&t=13223&p=173205#p173205
Neither of the chips pictured in that thread are ARM1s I'm afraid. So there's probably just a small sample run in 1985, then a small production run in mid 1986.

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IanB
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Re: ARM1 versions / batches

Post by IanB » Wed Dec 19, 2018 3:14 am

firthmj wrote:
Tue Dec 18, 2018 4:26 pm
Most of pictures I have been able to find have been of the same batch of chips, dated week "8625", and labelled "AUTUMN" (is that a code name or a season?)
Mine is also "8625" and "Autumn"

The serial nunber of the unit is 25-ANC13-1000032 if that's any help

BTW The PSU in the ARM evaluation unit has RIFA caps like the BBC/Master PSUs so make sure they are changed before trying to power one up.

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Re: ARM1 versions / batches

Post by Boydie » Wed Dec 19, 2018 7:10 pm

Both mine are 8625 and Autumn as well.

Neither has a proper serial number, but one has a “51” label on the board, the other “56”. I’m guessing this was Acorn’s internal serial system. If so, it gives a minimum to the number if Arm1’s made.
Last edited by Boydie on Wed Dec 19, 2018 7:13 pm, edited 2 times in total.

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flynnjs
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Re: ARM1 versions / batches

Post by flynnjs » Thu Dec 20, 2018 11:30 pm

SarahWalker wrote:
Tue Dec 18, 2018 6:59 pm
Neither of the chips pictured in that thread are ARM1s I'm afraid. So there's probably just a small sample run in 1985, then a small production run in mid 1986.
No, the wafers were clearly not ARMs but in the same box there was a
packaged device which I thinks was. At the time I hadn't seen the ES in
the 2/4MB copro but now I've seen that I'm going to go back and check
what's in the box and compare.

firthmj
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Re: ARM1 versions / batches

Post by firthmj » Fri Dec 21, 2018 8:45 pm

SarahWalker wrote:
Tue Dec 18, 2018 6:59 pm
My next question is about the A500 computer (not to be confused with the A500 second processor). I originally had the impression that this would have had an ARM1, but the older instance described at Chris's Acorns has an ARM2:

http://chrisacorns.computinghistory.org ... /A500.html

Were all of them at least ARM2, or were there early ones that had ARM1s fitted?
I believe most if not all A500s were fitted with ARM1s initially. Most would have been upgraded to ARM2 so they could still be used as development machines, with some having prototype ARM3s.
Does this mean that the ARM1 and ARM2 were pin compatible and interchangeable?

The two A500s on the Chris’s Acorns page seem to have different types of sockets for two of the main chips - sadly the picture of the (older) one that hadn’t been upgraded with an ARM3 daughter board isn’t clear enough to read the two chips to see exactly what they are.
Last edited by firthmj on Fri Dec 21, 2018 8:45 pm, edited 1 time in total.
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Boydie
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Re: ARM1 versions / batches

Post by Boydie » Sat Dec 22, 2018 8:49 am

They’re VIDC1 (production Arcs used VIDC1a) in the rear-right corner and early MEMC near the ARM.
Not sure if ARM1 and 2 are pin-compatible, but my A500 (ARM2) is an Issue B board. Could be that Issue A was socketed for LCC chips (ARM1) and Issue B for PLCC (ARM2)...

edit: Just checked the ARM Family Datasheets - if the ARM1 pinout on wikipedia is correct, the pinouts are near-identical, certainly close enough for a minor bodge.
Last edited by Boydie on Sat Dec 22, 2018 10:16 pm, edited 1 time in total.

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SarahWalker
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Re: ARM1 versions / batches

Post by SarahWalker » Sun Dec 23, 2018 11:09 am

Even if they aren't compatible, it's entirely possible that the boards could have been reworked. They'd need some rework anyway, to allow for the MEMC1 w/ARM2 workarounds.

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